PB-213 511
A State-of-the-Art Report on
Systems Incorporating
Highway Transportation
Environmental Protection Agency
1972
Distributed By:
National Technical Information Service
U. S. DEPARTMENT OF COMMERCE
5285 Port Royal Road, Springfield Va. 22151
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BIBLIOGRAPHIC DATA
SHEET
1. Report No.
EPA-SW-99-72
3. Recipient's Accession No.
PB 213-511
4. Title and Subtitle
Solid Waste Transfer Stations; A State-of-the-Art Report on
Systems Incorporating Highway Transportation
5- Report Date
1972
6.
7. Authot(s)
Tobias A. Hegdahl
8. Performing Organization Kept.
No.
9. Performing Organization Name and Address
U.S. Environmental Protection Agency
Office of Solid Waste Management Programs
Cincinnati, Ohio 45268
10. Project/Task/Work Unit No.
11. Contract/Grant No.
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
Office of Solid Waste Management Programs
Washington, D.C. 20460
13. Type of Report & Period
Covered
Final Report
14.
15. Supplementary Notes
16. Abstracts <
This state-of-the-art report on highway transportation systems for solid waste traces
their historical development in the United States, economic justification for their
use, basic design and location considerations, and basic cost criteria for constructing
owning, and operating. The report deals only with truck-to-truck transfer systems—
i.e., from route-collection vehicles to large-capacity transfer vehicles. Basically,
two categories of these transfer systems are discussed: direct-dump and compaction.
An extensive bibliography and specific appendixes are included. '
17. Key Words and Document,Analysis. 17o. Descriptors
*Refuse disposal, *Collection, *Storage, *Transfer, Highway transportation, Bulk
transporters, Site selection, Operating costs, Construction costs, Reviews
17b. Identifiers/Open-Hnded Terms
*Solid waste management, ^Transfer stations, United States
17c. TOSATI Field/Group
1313
18. Availability Statement
£^ ; Release to public
19..Security Class (This
Report)
UNCLASSIFIED
20. Security Class (This
Page
21- No. of Pages
170
22- Price
FORM NTIS-35 (REV. 3-72)
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EPA-SW-99-72
SOLID WASTE TRANSFER STATIONS
A State-of-the-Art Report
on Systems Incorporating Highway Transportation
This report (SW-99) was written by TOBIAS A. HEGDAJ1L
U.S. ENVIRONMENTAL PROTECTION AGENCY
1972
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An environmental protection publication in the solid waste
management series (SW-99).
This report is printed -as submitted by :the -Systems Management
Division-, 'which is responsible for its editorial and technical
content. Mention of 'commercial products does not constitute
endorsement by the U.S. Government.
II
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PREFACE
The rapid urbanization of the United States--71 percent of the
Nation's 203 million people today are concentrated in urban areas--
has perpetrated a crisis in locating suitable and unobjectionable
sanitary landfill disposal sites. By the year 2000, 85 percent of
a maximum estimated 320 million population will be concentrated
in a few megalopoles. Even now, in terms of amounts of wastes
generated and spatial concentration, cities are troubled most by
disposal problems. Public officials in many of these communities
are grappling with the same antithesis; the most accessible open
acreage around the city is already consumed while the demand for
disposal sites accelerates. So the sites are being located farther
and farther from the urban area. Collection vehicles are forced
to haul longer distances, and solid waste handling costs, that already
must vie for the public dollar, rise.
The concept of transferring waste from many route-collection
vehicles to large-capacity transfer vehicles can afford one solution
to this increasingly intractable problem. This transfer of solid
waste to large-pay load haulers, to conserve the travel time of the
whole collection vehicle force, is not a new practice. The transfer
station itself is basically very simple, but it can be designed to
incorporate several different types of transfer systems. And as its
use has become more prevalent, particularly in the last decade,
manufacturers have developed specialized equipment to meet the
demand.
This report is devoted largely to a discussion of the design,
operation, and economics of truck-to-truck transfer systems cur-
rently in use in the United States. The drop-box, or roll-on/roll-off
type container transfer system, although a popular and effective
method used by many industries, institutions, and smaller communi-
ties, has been excluded, because it has not yet been employed in a
central transfer operation that serves as an unloading point for route
collection vehicles.
The existing technology described here should be considered
discerningly in solving local solid waste problems. The implicit ques-
tion is this: Will use of a transfer station, as an intermediate handling
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step, represent an overall collection-transportation cost
savings? No general rule of thumb can be formulated to deter-
mine this; no two areas are the same. Although basic economic
criteria upon which to base the need for a transfer operation
are presented, the numbers used in any specific analysis must
be derived from a study of local conditions and variables.
Beyond the "short haul" transfer systems described, transfer
modes for longer distances are gaining impetus as urban entities
look to even more remote localities. A few communities have
been transferring waste via barges, and the use of railroads has
been under consideration for several years. Rail transfer oper-
ations undoubtedly will be employed if contract and political bar-
riers can be overcome. As part of its interest in technology
application in this area, the Office of Solid Waste Management
Programs is seeking now to initiate a rail-haul demonstration
project.
We hope that this information on current trends in solid
waste transfer, compiled by the Office of Solid Waste Manage-
ment Programs into a single source, will be helpful.
--Clyde J. Dial, Director
Systems Management Division
Office of Solid Waste Management
Programs
IV
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CONTENTS
Chapter Page
I DEVELOPMENT IN THE UNITED STATES 1
Historical Review 1 :
Transfer Station Locations 4;j
Economic Justification 7
Transfer Station Systems and Equipment 18
Operation and Management 25
II DESIGN AND LOCATION CONSIDERATIONS 27
Site Selection 27
Design Considerations 29
Building Design 29
Transfer Systems and Plant Layout 37 '
III TRANSFER STATION COSTS 82 ;
Construction Costs 82
Equipment Costs 87
Processing Equipment 87
Haul Equipment 89
Owning and Operating Costs 90
REFERENCES 95
BIBLIOGRAPHY 96
APPENDIX A Location and Other Character- 104
istics of Transfer Stations in
the United States
APPENDIX B Manufacturers of Transfer 109
Station Equipment Systems
APPENDIX C..; Specifications for Stationary 110
Compactors and Enclosed
Transfer Trailers
APPENDIX D An Accounting System for 111
Transfer Station Operations
APPENDIXE Site Surveys 131
APPENDIX F Comparison of Two Large- 15H
Volume Transfer Stations
v
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FIGURES
Page
1 Direct haul to the disposal site by each collection vehicle
may result in large hauling costs if a considerable distance
is involved. 2
2 When the contents of several collection trucks are transferred
to one large transfer vehicle, significant haul cost savings may
result. ; 2
3 The solid waste transfer stations as of 1971 are located as
indicated on the map. 5
4 Over 75 percent of the transfer stations have been placed in
operation since 1965. 6
5 The round-trip driving time at which transfer and haul becomes
justifiable is shown by the breakeven point for each crew size. 19
6 A direct-dump transfer station in which a backhoe is used to
compact and distribute the load. 2i
7 In a compaction pit transfer system a backhoe is used to j
compact the waste before it is pushed into a transfer trailer. 21
8 Enclosed reinforced steel trailers are utilized in horizontal
compaction transfer systems. ! 22
i
9 In some transfer systems stationary compactors are used for
loading and compacting waste into the rear of a transfer trailer. 22
10 Small direct-dump transfer stations are sometimes constructed
with only a small shelter covering the unloading area. 31
11 Although open-air, direct-dump transfer stations are usually
aesthetically objectionable, they are sometimes used in small-
volume operations. 31
12 An open-air, direct-dump transfer station may be aesthetically
acciiptabh' when the operation is well hidden by careful land-
scaping. 32
13 Sheet metal structures are often used to house transfer station
operations. 33
14 Transfer stations of concrete construction present a very
pleasing appearance. 33
15 Brick structures are occasionally used to house transfer station
operations. 34
16 When scales are utilized, a scale house should be provided for the
scalemaster and his records. 36
vi
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Page
17 Scales incorporating a printer and calculator can speed up
the weighing operations considerably. 36
18 The maximum densities allowable in an 80 cu-yd trailer are
shown at various empty trailer weights when a 16,000-lb
tractor is used and a 72,000-lb legal gross weight limit exists. 43
19 The maximum payloads allowable in an 80 cu-yd trailer are :
shown at various empty trailer weights when a 16,000-lb
tractor is used and a 72,000-lb legal gross weight limit exists. 43
20 The maximum densities allowable are shown at various trailer
capacities when the empty weight of the tractor-trailer rig is
40,000-lb and a 72,000-lb legal gross weight limit exists. 44
21 The total annual hauling cost from a transfer station can be
significantly reduced by maximizing the average payload per
trip. 45
22 The stationary backhoe used in many direct-dump transfer.
systems is permanently mounted and serves only a few
loading hoppers. 49
23 The self-propelled backhoe' used in many direct-dump transfer
systems moves from hopper to hopper. 49
24 The direct-dump transfer stations in King County, Washington,
are attractively housed under a steel roof. 50
25 The loading hoppers utilized in direct-dump transfer stations
are used to funnel the waste into open top trailers located one
level below. 50
26 The traffic flow and plant layout of a typical direct-dump transfer
station in which backhoes are used for compaction. 52
27 Self-propelled hydraulic tippers are used for open-top transfer
vehicles in San Francisco. 54
28 A hydraulic scooper is used to unload transfer vehicles in
King County. Washington. 54
20 As indicated in this floor plan of the compaction pit transfer
station in San Francisco, simultaneous loading of two transfer
vehicles and unloading of 17 collection trucks can be performed. 57
30 As indicated in this plot plan of the compaction pit transfer
station in San Francisco, traffic flows smoothly with no inter-
ference between collection trucks and transfer vehicles. 58
VI1
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Page
31 In a transfer trailer utilized in an internal compaction trailer
system, the waste is loaded through the top sliding door via a
hopper. 61
32 Horizontal compaction .transfer trailers utilize hydraulically
powered bulkheads to eject the load out the rear doors. 61
33 The internal trailer compaction system is best suited for low
volume operations. 62
34 A drive-through system for unloading incoming vehicles is
sometimes utilized in some internal compaction trailer systems. 62
35 At the transfer station, there can be a stationary power source
for operating the hydraulic system on an internal compaction
transfer trailer. 64
36 An internal compaction trailer may be equipped with a gasoline -
engine-powered hydraulic system. 65
37 A mobile hydraulic power source may be used for unloading
compaction transfer trailers at the disposal site. 67
38 In a stationary'compactor transfer system, transfer trailers
are locked to the stationary compactor for loading. 69
39 The stationary compactor transfer system has become very
popular in small-volume operations. 69
40 In this type of small volume transfer station, incoming solid
waste is dumped directly into the stationary compactor hopper. 71
41 In this type of transfer station, incoming solid waste is stock-
piled on the floor during peak delivery periods and is .then
loaded into the stationary compactor hopper with a front-end
loader. 71
42 In this incinerator that was converted to a stationary compactor
transfer station, the crane bucket is used to charge the conveyor
from the storage pit. 72
43 When an inclined conveyor is used to charge the stationary com-
pactor hopper, a simple single level building design can be
utilized. 73
44 In some transfer stations, hydraulic push-pits are used as both
a means of storage and as a means of loading the stationary
compactor hopper. 73
VLI I
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Page
45 A permanent concrete push-pit system is sometimes used for 75
charging solid waste into a stationary compactor hopper.
46 This portable steel push-pit system for charging solid waste
into a stationary compactor hopper is shown independent of
the transfer station to illustrate the construction. 76
47 An ejection bulkhead utilized on a compaction transfer trailer
pushes the waste out through the rear doors. 78
48 Small yard tractors are often utilized for moving trailers into
and out of loading position. 80
49 Conventional tractors are used for hauling transfer trailers to
and from the disposal site. : 80
TABLES
Page
1 Capital costs of collection truck 10
2 Annual time cost of collection truck . 11
3 Usage cost per mile for collection truck 12
4 Five-ton payload collection truck-unit haul costs 14
5 Capital costs of transfer vehicle 14
6 Annual time costs of transfer vehicle 15
7 Usage cost per mile for transfer vehicle 16
8 Maximum motor vehicle measurements for each State 40
9 Construction costs of transfer stations exclusive of land 84
and equipment
10 Construction costs of a King County, Washington, transfer 86
station
11 Owning and operating costs of transfer stations 91
12 1968 Cost breakdown for seven transfer stations in King County,
Washington 93
IX
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SOLID WASTE TRANSFER STATIONS
A State-of-the-Art Report
on Systems Incorporating Highway Transportation
CHAPTER I
DEVELOPMENT IN THE UNITED STATES
Historical Review
The basic concept of transferring solid waste from a relatively
small payload route-collection vehicle to a bulk hauler has been
practiced for several decades. Reducing the travel distance of
several collection vehicles by replacing them with one large payload
vehicle going to the disposal site offers savings (Figures 1 and 2).
The savings, however, must recover the cost of owning and operating
the transfer station and transfer vehicles. The economics will be
discussed later in this chapter. *
New York City started a system of barge transfer in the 1930's,
and Chicago utilized rail transfer to some extent during the 1930's and
1940's. Truck transfer systems began emerging on a significant scale
in the 1950's and have developed into the major haul medium. The only
significant barge transfer system currently in operation is in New York
City where nine installations have been established between 1937 and
1965. Rail transfer is not utilized to any significant extent, but is
receiving a great deal of study and consideration. With the tremendous
volumes of solid waste concentrated in our urban areas, extensive rail
haul may soon become a reality as contract, routing, disposal site,
materials handling, and location difficulties are overcome. Indeed,
1
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COLLECTION AREA
' DISPOSAL SITE
COLLECTION VEHICLES
Figure 1. Direct haul to the disposal site by each collection vehicle may result.
in large hauling costs if a considerable distance is involved.
COLLECTION AREA TRANSFER1'
STATION
TRANSFER VEHICLES PATH
COLLECTION VEHICLES PATH
DISPOSAL SITE
Figure 2. When the contents of several coflection trucks are transferred to lone
large transfer vehicle, significant haul cost savings may result.
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as the location of available disposal sites become increasingly distant,
only the tremendous bulk hauling capabilities of a rail system appear
economically feasible.
The location of disposal sites became an acute problem in the
1960's not only in the largest urban areas but in many intermediate and
smaller-size cities. As a result there was a tenfold increase in the
number of transfer stations over the previous decade as transfer became
a necessary economic alternative to direct haul to distant disposal
sites. To meet the increased demand, specialized highway bulk transport
vehicles have been designed along with processing equipment to maxi-
mize payloads within legal highway weight restrictions. The efficiency
of a transfer station depends largely on the speed with which transfer
vehicles are loaded and unloaded. The city of Chicago pioneered the
development of the large-capacity, van-type transfer trailers, but
encountered difficulty in the unloading operation. Finally a decision
was made to employ an endless belt type of moving floor unloader, but
even this proved somewhat inefficient. Since the early 1950's when
this system was used, many manufacturers have capitalized on the vast
increase in demand and have developed trailers with telescoping
hydraulic cylinders that move bulkheads from front to rear for rapid
unloading. Various other unloading systems designed by operating
authorities have also been developed for specialized use. More
detailed equipment descriptions will be given later.
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Transfer Station Locations
An inventory of nearly all the solid waste transfer stations in
the United States as of 1971 was made with the aid of the states, equip-
ment manufacturers, and the 1968 National Survey of Community Solid
Waste Practices. A list of the locations, their ownership, miles to
disposal site and annual tonnage are given in Appendix A. A few small
installations may have been overlooked, but each location listed
represents a facility that serves as a central transfer point utilizing
a truck and trailer system (Figure 3). The fact that over 75 percent
of the transfer stations have been placed in operation since 1965, I
clearly illustrates their relatively recent popularity (Figure 4).
Transfer stations have been employed in many large cities for a
number of years and several areas have incorporated them as an integral
part of their long-range plans. In some cases operating authorities
have developed specialized equipment for processing and hauling. In
recent years emphasis has been placed on the regional approach to solid
waste management, and in some areas this has resulted in the construction
of central transfer stations that haul to large regional landfill sites.
The use of systems of this type will undoubtedly increase as the
economy, efficiency and effectiveness of the regional approach is
realized.
The potential savings in transfer station utilization has unfortu-
nately misled some municipal officials. In attempting to justify a
transfer station through the use of a rule of thumb for breakeven haul
distance, some communities have constructed transfer facilities that
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Figure 3. The solid waste transfer stations as of 1971 are located as indicated on the map.
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1940
1950 1960 "1965' 1970
"YEAR""
Figure 4. Over 75 percent of the transfer stations have
been placed in operation since 1965
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are unnecessary and even more costly than direct haul. City officials,
beset by many other problems, and with insufficient time for necessary
study, have been persuaded to construct a transfer station as a method
of reducing costs in their rapidly increasing solid waste budget. In
some cases transfer stations have been constructed without the location
of disposal sites being firmly fixed, or at least not determined for
more than a few years in the future. Careful planning for long range
future needs is a must when capital expenditures for transfer stations
are under consideration.
Economic Justification
The utilization of a transfer station can only be justified by the
total cost reduction and convenience it offers to a given service area.
These potential savings must relate directly to the needs within a
service area whether the transfer station is intended to serve only
the collection vehicle fleet of a municipality or to serve the general
public on a free or user-fee basis. A transfer station will lower
neither the door-to-door collection cost nor the disposal cost. Savings
are realized only by reducing the haul distance from the collection
zone to the unloading area. Because collection trucks travel only
short distances to unload at a transfer station, they can be back on
their routes while a transfer vehicle containing several collection
truck loads is traveling to a distant disposal site.
Although a transfer operation offers potential savings it requires
an extra materials-handling step and the construction of a transfer
7
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facility. The associated costs must be recovered or money will be lost.
in the transfer operation. The costs that are incurred are as follows:
(T) the capital expenditures for land, structures, and equipment;
(2) the labor, utilities, maintenance, operating, and overhead costs
at the transfer plant;
(3) the labor, operating, maintenance and overhead costs incurred
in the bulk hauling operation.
Costs are saved with the utilization of a transfer operation
because:
(1) the non-productive labor time is. cut since collectors no longer
ride to; and from the disposal site; therefore, the larger the
collection crew the greater the savings;
(2) any reduction in mileage traveled by the collection trucks
results in a savings in operating costs and in addition, it may-
be possible to reduce the number of collection crews needed
because?of increased productive collection time.
Anyone considering a transfer operation must therefore determine
if the savings will exceed the costs. The primary variable is the
distance to the disposal site. Attempting to apply a rule of thumb
(i.e., a 10-miTe haul distance justifies transfer) to this determination
is unrealistic and mere guesswork unless a study is made of local con-
ditions. A decisive distance in one area may be totally misleadinc] in
another. Factors such as wage rates, type of access roads, collection.
truck capacity, and size of collection crews (i.e., one man, two men,
etc.) change the breakeven distance considerably.
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Although distance to the disposal site is important in comparing
direct haul with transfer and haul, a more realistic criteria is the
time necessary to travel the distance. Variables such as routes taken,
traffic conditions and speed limits could result in a time of 15 minutes
to cover a 10 mile distance in one area and an hour in another area.
Also the major item in total haul cost is labor which is directly related
to time and not distance. For these reasons the usual cost per ton per
mile unit of comparison will be replaced by the more realistic unit of
cost per ton per minute in the following analysis.
To determine whether a transfer system is economically feasible,
it should be compared with direct haul. Such a comparison requires
realistic data applicable to the particular service area in question.
If a contractor or municipality has accurate figures for the hourly cost
of owning and operating their collection trucks, this information can
be utilized, and the detailed analysis that follows for determining
hourly costs is not necessary. If, however, these costs are not avail-
able, the appropriate figures should be substituted into the example
that follows.' Costs applicable to a private collection contractor such
as taxes, licenses, and insurance may not be applicable to a municipal-
ity, and should be deleted from the analysis.
Assume that a collection agency uses trucks that average five tons
per load, that the crew consists of one driver and two collectors, and
that all three men ride to the disposal site located 20 miles from a
transfer station site under consideration. The haul cost analysis for
the collection truck will be presented first followed by that for a
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transfer system. After the necessary figures from these analyses are
obtained, a graphical comparison between direct haul and transfer and
haul will be presented.
TABLE 1
CAPITAL COSTS OF COLLECTION TRUCK
T. ' Cost
Item
Compactor truck (diesel) $15,000
Ti res :
Rear: 4 @ $110.00 ' 440
Front: 2 0 $110.00 220
Total 660
Truck cost less tires $14,340
The capital costs for the collection truck, less tires, is $14,340
(Table. 1). Annual owning and operating costs can conveniently be broken
2
into those incurred on a time basis and those incurred on a usage basis.
Costs incurred on a time basis are depreciation, labor, insurance,
licenses, and taxes (Table 2). Cost incurred because of usage are
gas, oil, tires, repair, and maintenance (Table 3).
10
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TABLE 2
ANNUAL TIME COST OF COLLECTION TRUCK
it™
Depreciation on truck, less tires, over 6 years $ 2,390
(straight line)
Driver's salary 8,400
Collectors' salaries 2 @ $7200.00 14,400
Fringe benefits @ 25 percent of salaries 5,700
Interest on truck investment less tires @ 6% 860
Taxes and licenses 500
Insurance 500
Total annual time cost $32,750
The cost per minute assuming 260 working days per year and 8 hours per
day is:
260 days X Hours X 60 minuTeT = $0.260/m1nute
11
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TABLE 3
USAGE COST PER MILE FOR COLLECTION TRUCK
Cost
I A- i • i \
($/mile)
Fuel @ $0.20 per gallon and 4 miles per galIon $0.0500
Oil @ $1.50 per gallon and 5,000 miles per gallon 0.0003
Tires:
Rear: 4 @ 20,000 miles 0.0220
Front: 2 @ 30,000 miles 0.0073
Repair and maintenance 0.0500
Total 0.130
The transfer station site under consideration has been assumed to
be located 20 miles from the disposal point, and it should be located
centrally to the area it is intended to service. Although some collec-
tion trucks would have to travel less than 20 miles from their service
area to the disposal point, others would have to travel more than 20
miles. An overall average distance of 20 miles will be assumed.
Both, a time factor and a usage factor are available to analyze
the round trip of a collection truck from the transfer station site to
the disposal point. In the case of the collection vehicle only the
actual driving time is included in the cost analysis. The unloading
time is not considered because this step is always required regardless
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of whether the truck unloads at the transfer station or at the disposal
point. With the transfer vehicle, however, the extra materials-handling
time involved in loading and unloading must be considered. This will
be discussed in more detail later. For this example assume that the
actual driving time required for the 40-mile round trip is one hour. In
a specific case this time can be determined by actually timing the
vehicles. The time cost was previously determined to be $0.260 per
minute. Ultimately the unit of cost per ton per minute is required so
the usage cost must also be converted from a per-mile to a per-minute
basis. The total usage cost involved in the 40-mile trip is: $0.13 per
mile X 40 miles = $5.20. Since the trip requires one hour of driving
time the per-minute usage cost is: $5.20 -^60 min = $0.087 per min.
The total cost per minute for the collection truck is the summation of
time and usage costs which is $0.260 per min + $0.087 per min = $0.347
per min.
This figure is for a driver and two collectors riding to the
disposal site. Identical calculations can be made for the driver and
just one collector, and for the driver only by simply deleting their
labor cost from the total time cost; usage cost will not change. The
total costs become $0.276 per minute and $0.204 per minute, respectively.
Labor therefore represents a substantial portion of transportation cost.
These cost per minute figures can easily be converted'to the
desired cost per ton per minute units by dividing them by the average
payload of the truck which is assumed to be five tons (Table 4).
13
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TABLE 4
FIVE-TON PAYLOAD COLLECTION TRUCK-UNIT HAUL COSTS
Crew Sl> ($/ton/m1n)
Driver only 0.041
Driver and one collector 0.055
Driver and two collectors 0.069
An identical procedure is used to calculate the cost per ton per
minute for transfer vehicle haul. Assume ttiat a 75-cu yd tandem axle,
trailer is pulled by a tandem axle diesel tractor and that a 20- ton
payload can be carried. The capital cost, less tires, would total
$34,520 (Table 5) and the annual time costs total $22,130 (Table 6).
The usage cost per mile for the transfer vehicle is $0.196 (Table 7).
TABLE 5
CAPITAL COSTS OF TRANSFER VEHICLE
Transfer tractor (diesel) $16,500
Transfer trailer (75 cu yd) 20,000
Ti res :
Tractor - 8 rear tires @ $110.00 880
2 front tires G> $110.00 220
Trailer -80 $110.00 880
Total tire cost 1 ,980
Transfer vehicle cost less tires $34,520
14
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TABLE 6
ANNUAL TIME COSTS OF TRANSFER VEHICLE
Tl-am C°St
Item
Depreciation on tractor less tires over six
years (straight line) $2,570
Depreciation on trailer less tires over six
years 3,190
Drivers salary 9,600
Fringe benefits @ 25 percent of salary 2,400
Interest on transfer vehicle investment
less tires @ 6% 2,070
Taxes and licenses 800
Insurance 1,500
Total annual time cost $22,130
The cost per minute assuming 260 days per year and 8 hours per day is
$22,130 tn 177/m,_
260 days X 8 hours X 60 minutes *u.i///rmn
15
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TABLE 7
USAGE COST PER MILE FOR TRANSFER VEHICLE
Item ($/Xle)
Fuel @ $0.20 per gallon and 4 miles per gallon $0.0500
Oil @ $1.50 per gallon and 5000 miles per gallon 0.0003
Tires:
Tractor - 8 rear tires @ 20,000 miles 0.0440
2 front tires @ 30,000 miles 0.0073
Trailer - 8 tires @ 20,000 miles 0.0440
Repair and Maintenance 0.0500
Total usage cost per mile $0.196
A time factor and usage factor are now available for the analysis
of the transfer vehicles 40-mile round trip to the disposal site. As
mentioned previously, however, the time for a complete cycle of events
including loading, travel time and unloading must be included because
the transfer operation requires extra materials-handling steps. During
the actual travel time, both time and usage costs will be incurred but
during the loading and unloading time only time costs are involved.
Because the transfer vehicle is less maneuverable than the lighter
collection vehicle assume the round-trip driving time is 1.25 hours but
that each transfer vehicle and driver make four trips per day or that
each complete cycle requires two hours. Therefore, each round trip
requires 45 minutes (2.00 hr - 1.25 hr) of unproductive time in loading
16
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and unloading. The cost of this unproductive time is $0.177 per min X
45 min = $7.97. For the 20-ton payload the cost per ton is $7.97 4- 20
tons = $0.40 per ton. This cost will be plotted at zero travel time in
i
the graphical cost comparison presented later. For the 1.25 hours
(75 minutes) of driving time both time and usage costs are Incurred.
The time cost equals $0.177 per minute. The usage cost must be converted
to a per minute basis:
The total cost per minute while traveling is therefore:
$0.177/min + $0.105/min = $0.282/min
This cost is simply divided by the 20 ton payload to get the desired
cost per ton per minute:
*n 907
= $°-014 Per ton Per minute-
2o tons
A transfer operation involves not only haul costs but the costs
involved in owning and operating the transfer station. This cost
includes all depreciation of buildings and equipment, labor, utilities,
repair and maintenance, overhead and operating expenses of equipment
kept permanently at the station. In this example, instead of attempting
to determine the cost based on a hypothetical installation, a figure
of $1.50 per ton will be used. This is representative of what is
experienced in typical transfer stations in the United States.
17
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A graphical comparison between direct haul and transfer and haul
can now be made (Figure 5). The slope of each haul cost line is equal
i
to the cost-per-ton-per-minute figure determined for each case. For
I
the transfer and haul operation, the unproductive costs of owning and
operating the transfer station plus the unproductive costs of loading
i , •
and unloading the transfer vehicles must be included. These costs ;
($1.50 + $0.40 = $1.90 per ton) are plotted at zero travel time in
Figure 5. It should be emphasized that the abscissa of Figure 5 is the
actual travel time involved and not the total-round trip time. The
points where the collection vehicle lines intersect the transfer and
haul lines are the breakeven points for each crew size. For the three -
man collection truck, transfer becomes justifiable at round-trip travel
times of over 35 minutes and with one and two man trucks at 71 and 46
minutes, respectively.
Transfer Station Systems and Equipment
The trend toward solid waste transfer has led to the development
of equipment specifically suited to the need. Early transfer station
operations relied completely on equipment built by various manufacturers
tg specifications of the operating authority. In the 1960's, however,
as the popularity of transfer increased rapidly, solid waste equipment
manufacturers developed specialized processing and haul equipment. At
the present time those interested in a transfer operation have the
option of either designing their own system and writing specifications
for desired equipment or of buying specialized equipment from the manu-
facturers and designing the system around it.
18
-------
6.00 w.-
5.00 —
4.00 -
3.00 -
2.00
1.00
0.00
BREAKEVEN
POINTS
UNPRODUCTIVE COST OF
LOADING AND .UNLOADING - $0.40/tOP
1 TRANSFER VEHICLE '
COST OF OWNING
AND OPERATING = $'.50/ ton
TRANSFER STATION
40 60 80
ROUND-TRIP DRIVING TIME (minutes)
Figure 5. The round-trip driving time at which transfer and haul becomes justifiable
is shown by the breakeven point for each crew size.
19
-------
Two basic types of transfer systems have developed as a result of,.
this option: The first is the basic direct-dump system where a collec-
tion truck dumps by gravity into a large open-top trailer. The trailer
is located under a funnel shaped hopper to prevent spillage and a
backhoe is usually used to compact and distribute the load after it
has been placed in the trailer (Figure 6). An offshoot of this system
utilizes a dumping pit where a crawler tractor crushes and compacts the
waste before pushing it into the trailer via the hopper (Figure 7).
Because of the densities achieved with the compaction tractors, a back-
hoe is usually required for load distribution only. The compaction pit
system is used primarily in high-volume transfer stations because of
the expense df incorporating the extra equipment whereas the basic
direct dump system has been used in both small and large installations.
All direct dump systems are characterized by the fact that open-top
trailers are used and the equipment employed is usually not specifically
predesigned for solid waste transfer. Some type of cable system is
usually employed to pull the loads out of the rear of the trailer at
the disposal site. The specifications for hoppers, trailers, and any
other desired equipment are written and bids are let to various manu-
facturers.
The sec'ond basic transfer system utilizes hydraulic pressure to
achieve horizontal compaction of the waste within the trailer. Two
methods have been used to achieve compaction but both are characterized
by the use 'o'f 'enclosed reinforced steel trailers specifically manufac-
tured for solid waste transfer (Figure 8). The first compaction method
20
-------
Figure 6. A direct-dump transfer station in which a backhoe
is used to compact and distribute the load.
Figure 7. In a compaction pit transfer system a backhoe
is used to compact the waste before it is pushed into a
transfer trailer.
21
-------
Figure 8. Enclosed reinforced steel trailers are utilized
in horizontal compaction transfer systems.
Figure 9. In some transfer systems stationary compactors
are used for loading and compacting waste into the rear of
a transfer trailer.
22
-------
is partially a direct-dump operation in that waste is dumped directly
into the trailer near the front. A hydraulic-powered bulkhead traverses
the length of the trailer and compacts the waste against the rear doors.
The entire compaction process is self-contained within the trailer body
and the bulkhead also pushes the load through the rear doors at the
disposal site. The second compaction method involves the use of a
stationary compactor (Figure 9). The transfer vehicle is backed up and
securely fastened to the compactor. Waste is fed by gravity into the
compactor chamber from an overhead hopper located above. The compaction
ram forces the waste forward through the rear doors of the trailer in
horizontal reciprocating cycles. This trailer is also equipped with
a hydraulic-powered bulkhead which traverses the length of the trailer
for unloading at the disposal site. Either compaction method can easily
produce maximum legal payloads. A list of the major manufacturers of
transfer station equipment is given in Appendix B. This list includes
only major manufacturers of total package, transfer-station equipment
systems.
Either of the two basic transfer systems may be equipped with
storage provisions if they are needed to prevent queuing problems with
incoming vehicles during peak delivery periods. Some systems are more
adaptable to the incorporation of storage than others. If the compaction
pit direct-dump system is employed, a large storage area can be made
available in the pit much the same as in incinerator operations. Direct
dumping from one vehicle to another requires many dumping hoppers and
trailers to accommodate heavy incoming traffic flow unless waste is
23
-------
stockpiled in the unloading area and later pushed into the hoppers with •
a front end loader. In compactor systems, front-end-loaders, conveyors,
crane buckets, and specially designed hydraulic push-pits can be utilized
to charge the compactors from a floor or pit storage area.
Any transfer system can be an enclosed or nonenclosed operation.
A nonenclosed or open-air transfer station is cheaper to construct, of
course, but aesthetic and public health problems will probably result
unless the facility is well hidden or isolated. Open-air installations
are used primarily in dry, year-round warm climates or in small direct
dump operations. In many areas solid waste transfer operations are
housed in very aesthetically designed structures resulting in very little
neighborhood opposition and few citizens complaints.
One method of transfer not investigated as part of this study
that has had application in reducing costs in rural areas, apartment
complexes, commercial establishments, industries, and recreational
areas is the drop box, the roll-on/roll-off, and the lift-on/lift-off
container. In this system the full container is replaced with an empty
one and then carried to the disposal site. These systems can be used
in connection with compaction devices to achieve large payloads. Some
manufacturers are conducting research of this system in connection
with a large municipal transfer station as an alternative to the use of
transfer trailers. One manufacturer is marketing a mobile transfer
system. Solid waste picked up on the collection route is compacted
into a seven cu-yd detachable container by a hydraulic apparatus on a
small truck. This truck drops a full container off at a transfer yard,
24
-------
picks up an empty one, and then proceeds back to the collection route.
The full containers are later picked up and emptied into a large com-
pactor truck which hauls the solid waste to the disposal site.
Operation and Management
A transfer station may be designed to serve only as part of the
collection system of a contractor or city or in addition to serve as a
convenient solid waste unloading site for the general public. As the
number and types of incoming vehicles increase, both the initial con-
struction costs and the station operating costs rise. If only large
packer trucks use a transfer station, less processing is required to
produce legal payloads and less traffic congestion is encountered. On
the other hand, if the general public has access to the site, much of,
the incoming waste will be uncompacted, additional unloading space must
be provided, and more traffic flow regulation is required.
The simplest and most economical transfer operation is therefore
one that has the sole purpose of providing haul cost savings to a fleet
of contractor or city-owned collection trucks. Waste inputs are rela-
tively predictable and record keeping is simple. Weighing of incoming
vehicles may not be required if the outgoing transfer vehicles are
weighed. The utilization of an inexpensive direct-dump system may be
desirable because of the precompacted nature of the incoming waste.
A transfer station which is open to the general public is usually
financed either by a system of user-fees or from some type of general
fund. To break even with a user-fee system, the charge at the transfer
25
-------
station must cover both the cost of transfer and disposal. It must,
therefore, be cheaper for the prospective user to pay the transfer fee
than to haul directly and pay only the disposal fee. The cost per ton
for a user-fee-financed transfer system will be higher because of
necessary weighing and billing expenses. A transfer system financed
from a general fund will be subjected to a heavy incoming traffic flow
because no direct charges are made. This type of operation is often
used in an effort to reduce indiscriminate dumping within the area.
In a transfer station utilized by only a fleet of city or private
collection trucks, the hours per day and days per week of station
operation are set to meet the needs of the collection schedule. Open
access transfer stations, however, are sometimes operated a specified
period of time, seven days per week for the convenience of customers.
If storage is available, dumping may be permitted 24 hours a day with
the transfer vehicles operating during a single daytime shift. To avoid
excessive overtime costs, most transfer operations, operating six or
seven days a week, utilize a rotating shift labor scheduling procedure.
In summary, transfer station design should not be attempted until
a determination is made of who will use the facility and how the opera-
tion will be financed. Plant layout and the type of transfer system
to be utilized are largely dictated by the type of incoming vehicles.
26
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CHAPTER II
DESIGN AND LOCATION CONSIDERATIONS . '.
A detailed economic analysis of transfer station feasibility cannot
be made until a transfer system suited to the particular area is decided
upon. Major design decisions concerning buildings, processing equipment
and haul equipment for systems basically equivalent may have to be
determined at the discretion and personal preference of the deciding
authority. Basic criteria upon which to analyze different systems should
not, however, be ignored. Primary considerations related to site selec-
tion are: (1) traffic accessibility; (2) type of neighborhood (zoning);
(3) proximity to collection routes; (4) proximity to disposal site.
Basic considerations related to the transfer system are: (1) volume
handled; (2) haul vehicle restrictions; (3) type of wastes handled;
(4) types of incoming vehicles; (5) processing equipment; (6) peak load
allowances - storage; (7) traffic patterns.
Site Selection
Ideally a transfer station should be located so that costs are
minimized in the tradeoff between the travel time of the route-collection
vehicle to the transfer point and the travel time of the transfer
vehicle to the disposal site. This may result in the need for several
transfer stations within a service area. Operations research techniques
have been used to develop mathematical optimization models for the
27
-------
number and location of transfer stations. In Mathematical Analysis of
Solid Waste Collection by Marks and Liebman of Johns Hopkins University,
3
one such example of this type of work is presented.
A limited number of sites will usually be available, however, and
often the acquisition of even one site may be difficult due to the
reputation of "garbage" being a bad neighbor. If several sites are '•
obtainable, the choice may be obvious because of proximity to waste-
generation areas and uncongested streets and freeways.
The type of neighborhood can have a large influence on the cost of
a transfer station. A residential section may be the ideal location :
from a waste concentration standpoint but considerable initial opposition
i
by residents of the area should be expected. To be aesthetically
acceptable, large capital costs in structures and landscaping may be !
necessary. If a residential location provides obvious advantages and1
neighborhood opposition is overcome, it is imperative to maintain a
"good neighbor" standing. This usually requires that all waste be
removed from the site at the end of each working day, and that the site
be kept free of litter and well maintained.
It may prove advantageous to locate in an industrially or commer-
cially zoned area even though a greater haul distance is involved. This
will probably result in fewer citizen complaints, a smaller investment
in buildings and landscaping, and fewer problems with access streets.
This does not mean sloppy operations will be condoned, but in these
areas the operation is less likely to be visible to the public.
28
-------
Of prime importance in site location is accessibility to streets,
i
highways, or freeways where fast moving traffic flows freely. Time
savings resulting from the use of rapid moving access routes may easily
offset additional distances resulting in usage of such routes. Indeed,
an authority may be well ahead if efforts are initially made to start
looking for a site in a centrally located industrially or commercially
zoned area near existing primary roads.
Again, every area must deal with its own set of conditions concern-
ing waste generation areas, zoning and access routes, but thorough con-
sideration should be given to the above-mentioned points before commit-
ment to a site location is made. Easy inflow and outflow of traffic
combined with a location as near as possible to waste generation areas
are of primary importance.
Design Considerations
Once a site has been selected a basic transfer system must be deter-
mined. A structure that is aesthetically acceptable to the surrounding
neighborhood can then be chosen to house the operation. The following
detailed discussion elaborates on the various considerations involved in
building design, plant layout, and system selection. The basic systems
briefly described in the previous chapter will be discussed in detail
along with the advantages and disadvantages of each.
Building Design. Buildings for housing transfer stations range
from none at all (open-air) to large concrete and steel structures that
are very pleasing in appearance. An open-air transfer station works
well only in a dry climate with year-round warm weather. In some areas,
29
-------
however, small transfer stations that employ a direct-dump system often
utilize only a small shelter over the unloading area (Figure 10) or in
some cases not at all (Figure 11). Unless open-air transfer stations
are well hidden or in remote areas, such as one example located in
Southern California (Figure 12), they often create aesthetic problems.
These stations are also faced with wind problems and require constant
policing to keep litter from accumulating. In many cases, operators of
open-air transfer stations have converted to an enclosed operation or,
i
strongly recommend that only enclosed installations be considered in j
rainy or windy climates. I
I
i
Conventional sheet metal, concrete, or brick construction is useld
i
i
I
in the majority of transfer station buildings (Figures 13-15). Any \
type of transfer system (direct-dump or compactor types) can be house'd
i
in any of the building enclosures above. Sheet metal buildings are i
usually cheaper to construct per square foot of space and can be erected
the fastest; they may not, however, be as architecturally attractive
as some concrete buildings. As mentioned earlier, the landscaping an'd
architectural requirements will usually become greater, the closer the
transfer station is to residential areas.
Transfer station buildings are usually equipped with water sprays
and/or ventilation fans for dust control and enclosed with chain link
fence to control litter and access. Buildings should also contain
rest rooms anrf an office for communication and record keeping purposes.
The foundation" requirements and physical dimensions of the building
cannot be determined until the plant capacity, layout, and type of
30
-------
Figure 10. Small direct-dump transfer stations are sometimes
constructed with only a small shelter covering the unloading
area.
Figure 11. Although open-air, direct-dump transfer stations
are usually aesthetically objectionable, they are sometimes
used in small-volume operations.
31
-------
oo
ro
Figure 12. An open-air, direct-dump transfer station may be aesthetically
acceptable when the operation is well hidden by careful landscaping.
-------
Figure 13. Sheet metal structures are often used to house
transfer station operations.
Figure 14. Transfer stations of concrete construction
present a very pleasing appearance.
33
-------
Figure 15. Brick structures are occasionally used to house transfer station operations,
-------
transfer system are determined. Keep in mind, however, that considerable
expense beyond that for the buildings proper is usually required in the
form of excavation, access roads, utility provisions, fencing, and land-
scaping.
The transfer station should be equipped with a scale to weigh
incoming vehicles especially if user-fees are levied. Estimation .of fees
on a volume basis can prove very inequitable. Accurate tonnage figures
also provide valuable information needed for future planning. In addi-
tion, a record of incoming loads permits close estimates on outgoing
transfer vehicle loads so legal highway weight restrictions are not
exceeded. Of course, this estimate is not necessary if outgoing loads
are weighed. Several large-volume transfer stations incorporate scales
in the transfer vehicle loading platform so a continuous weight readout
is available as the trailers fill up. In this way maximum payloads are
always achieved without risking costly fines for overweight conditions.
The expense of utilizing these scales, however, is seldom justified in
low-volume operations so estimates are necessary.
The scale must be capable of handling the largest incoming trucks
anticipated and a scale house should be provided for the scalemaster
and his records (Figure 16). If user-fees are charged, considerable
time can be saved by equipping the scale with a printer and calculator
for determining fees (Figure 17). In some large transfer stations the
scale is coordinated with a computer system so all weight data are
received instantly at a central data processing point for record keeping
and billing purposes.
35
-------
Figure 16. When scales are utilized, a scale house should
be provided for the scalemaster and his records.
Figure 17. Scales incorporating a printer
and calculator can speed up the weighing
operations considerably.
36
-------
Sanitation must be considered an integral part of any transfer
\
station operation. Besides creating public health hazards, unsanitary
conditions will quickly result in the loss of badly needed public
support. Operations must be kept free of litter and transfer vehicles
must be adequately covered during travel to the disposal site. High
pressure hoses should be available at the transfer station for frequent
washdown of storage areas, solid waste handling equipment, and transfer
vehicles. A vehicle washing center has been incorporated into the
design of some transfer stations. Frequent washdown of vehicles is a
routine part of the haul operation and adds immeasurably to the public
image of the overall solid waste management system.
Transfer Systems and Plant Layout. The basic transfer systems
described briefly in Chapter I are those that are currently used in the
United States. The system best suited to a specific area must be deter-
mined by considering local conditions. A system that has application
in one area may not be flexible enough in another. The advantages and
disadvantages of the various basic systems will be discussed as they
relate to such considerations as: volume of solid waste handled;
types of solid waste handled; transfer vehicle weight and size restric-
tions ; types of vehicles using the facility.
.The two basic transfer systems previously discussed were the direct-
dump system characterized by the use of open-top trailers, and the com-
pactor system characterized by the use of enclosed reinforced steel
trailers. Each system can be subdivided into the following categories.
37
-------
Direct dump-transfer systems: (1) Gravity dumping from one vehicle
to anotherrr-no compaction; (2) Gravity dumping from one vehicle to
another followed by load leveling and compaction with a backhoe; (3) Com-
paction pit method - waste is unloaded into a storage pit or onto a
floor area and crushed under crawler tractor treads before being pushed
over a ledge into an open trailer below. Load leveling is usually per-
formed with a backhoe. When incoming traffic is heavy, the first and
second methods may have an intermediate step whereby the waste is first
dumped onto a storage floor before being pushed over a ledge into the
open-top trailer.
Compaction transfer systems: (1) Internal compactor system - waste
is placed in the trailer through a door located on top and near the
front. Waste may be dumped directly from the collection vehicle through
the door or it may be pushed over a ledge and into the trailer by a
front-end loader working from a storage area. The internal hydraulic
compactor compacts the waste toward the rear of the trailer in cycles.
(2) Stationary compactor system - the trailer is backed up to the
compactor which horizontally pushes the waste through a door in the rear
of the trailer in reciprocating strokes. Waste can be fed to the com-
pactor in different ways as will be discussed later.
The following basic information applicable to any transfer system
is presented before each system is discussed in detail.
The primary purpose of the utilization of any transfer station is to
reduce costs through reduction in haul time. It follows that maximizing
the payload of each transfer vehicle is mandatory to fully utilize the
38
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costs savings of a transfer system. An upper limit, however, is placed
on the payload obtainable with a given transfer vehicle because of gross
weight and axle weight restrictions. In addition, State restrictions
on maximum lengths, heights, and widths that limit total volume must be
adherred to (Table 8). Maximum legal payloads for most State motor
vehicle codes will result from a vehicle configuration in which the
number of axles and their spacing allow an upper limit of combined dead
load and live load to the maximum permissible gross vehicle weights.
Some States allow multitrailer rigs to be used within certain overall
length restrictions, which will often be the vehicle configuration
whereby maximum payloads can be achieved. They are not compatible, how-
ever, with some transfer systems and usually complicate the unloading
operation. Trailer manufacturers are very familiar with vehicle con-
figurations that give maximum payloads under different State .motor
vehicle codes.
State highway regulations should be carefully checked before the
selection of a transfer vehicle is attempted; The designer is faced with
the legal limitations and must work backward to determine optimum vehicle
configuration. When a direct-dump operation with limited compaction is
used, a large-volume vehicle is required to obtain maximum payloads.
Compactor systems produce higher densities so smaller volume trailers
can be used, but necessary strength reinforcement increases tare weights,
thereby lowering payloads.
The primary goal is to determine an inexpensive and reliable method
of obtaining maximum payloads. Obviously the lighter the transfer
39
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-pi
o
TABLE 8
MAXIMUM MOTOR VEHICLE MEASUREMENTS FOR EACH STATE*
State
Alabama
Alaska
Ari zona
Arkansas
California
Colorado
Connecticut
Delaware
Dist. of Columbia
Florida+
Georgia
Hawaii
Idaho
Illinois
Indiana+
Iowa
Kansas+
Kentucky
Louisiana
Maine
Maryland
Massachusetts^-
Michigan*
Minnesota
.Height
(in)
162
. 162
162
162
162
162
162
162
150
162
162
156
168
162
162
162
162
162
162
162
162
162
162
162
-Width
(in)
96
96
96
96
96
96
102
96
96
96
96
108
96
96
96
96
96
96
96
102
96
96
96
96
Length
Single Double
trailer trailer
(ft) (ft)
55
60
65
55
60
65
55
55
50
55
55
55
60
55
55
55
55
55
60
. .55
. 55
. 65
55
. 55
N.P.
65
65
65
65
65
N.P.
65
N.P.
N.P.
55
65
65
65
65
60
65
65
N.P.
N.P.
65
N.P.
65
N.P.
Axle weights
Single
•Ob)
18,000
20,000
18,000
18,000
18,000
18,000
22,400
20,000
22,000
20,000
20,340
24,000
18,000
18,000
18,000
18,000
18,000
18,000
18,000
22,000
22,400
22,400
18,000
18,000
Tandem
(lb)
36,000
34,000
32,000
32,000
32,000
36,000
36,000
36,000
38,000
40,000
40,680
32,000
32,000
32,000
32,000
32,000
32,000
32,000
32,000
36,000
40,000
36,000
26,000
32,000
Gross comb.
weight
"(lb)
73,280
100,000
76,800
.73,280
76,800
74,600
73,000
73,280
70,000
66,610
73,280
73,280
76,800
73,280
72,000
73,280
73,280
73,280
: 73,280
73,280
73,280
73,000
: 143,000
. 73,280
-------
TABLE 8 (Cont'd)
Mississippi
Missouri
Montana*
Nebraska
Nevada*
New Hampshire
New Jersey
New Mexico
New York*
North Carolina
North Dakota
Oh io+
Oklahoma
Oregon+
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah+
Vermont
Virginia
Washington*
West Virginia
Wisconsin
Wyomi ng
162
162
162
162
N.S.
162
162
162
162
162
162
162
162
162
162
162
162
162
162
162
168
162
162
162
162
. 162
162
96
96
• 96
96
96
96
. 96
96
96
96
.96
96
96
96
96
102
96
96
96
96
96 .
96
96
96
96
96
96
55
55
60
60
70
55
55
65
55
55
60
55
55
60
55
55
55
65
55
55
60
55
55
60
55.
55
65
55
65
. 65
65
70
55
55
65
N.P.
N.P.
65
65
65
75
. N.P.
N.P.
N.P.
65
N.P.
65
65
N.P.
N.P.
65
N.P.
N.P.
65
18,000
18,000
18,000
18,000
18,000
2 2., 400
22,400
21 ,600
22,400
18,000
18,000
19,000
18,000
18,000
22,400
22,400
20,000
18,000
18,000
18,000
18,000
22,400
18,000
. 18,000
18,000
19,500
18,000
32,000
32,000
32,000
32,000
32,000
.36,000
32,000
34,320
36,000
36,000
32,000
32,000
32,000
34,000
36,000
36,000
36,000
32,000
32,000
32,000
33,000
36,000
32,000
32,000
32,000
32,000
36,000
73,280
73,280
76,800
71,146
76,800
73,280
73,280
86,400
85,000
73,280
73,280
78,000
73,280
76,000
71,145
73,280
73,280
73,280
73,820
72,000
79,900
73,280
70,000
76,000
73,280
73,000
73,950
*These figures should serve only as a rough guide because they are subject to change and certain
limitations. .
+Greater length and gross weights allowed on designated highways
N.P. - not permitted
-------
vehicle, the larger the payload. Controversy develops as to whether
this goal can be best accomplished with ah open-top direct-dump trailer
or an enclosed compactor loaded trailer. Open-top, tractor-trailer rigs
have empty weights ranging from about 26,000 to 33,000 Ib and the initial
purchase price is usually lower than the heavier compactor trailer rigs
which weigh from about 39,000 to 42,000 Ib. Assuming a gross vehicle
weight limit of 72,000 Ib, the open-top vehicles can carry a maximum
payload of about 19.5 to 23 tons while the enclosed compactor rigs are
limited to about 15 to 16.5 tons. Graphical comparisons of trailer
characteristics versus allowable densities and payloads clearly illus-
trate the hauling restrictions placed on transfer systems by legal
weight limits (Figures 18 to 20). Enclosed compactor trailers, however,
have definite time saving advantages in unloading and in their ability
to handle various bulky wastes. In addition, maximum payloads may be
difficult to obtain with certain types of wastes when using open-top
trucks. These points will be discussed in more detail later.
To obtain an idea of the sensitivity of total haul cost to payload,
assume that a transfer station handles 100,000 tons per year and that
the approximate total cost per transfer vehicle trip is $30, which is
a realistic figure. If each trip averages a 16-ton payload, 6,250
trips are required while a 20-ton payload requires only 5,000 trips.
Thus, 1,250 trips are eliminated giving a total annual savings of $37,500
(Figure 21). The total annual haul cost can therefore be reduced sub-
stantially by maximizing the payload each trip. The cost per trip is
nearly constant regardless of payload so transporting less than maximum
payloads increases the cost pe.P ton per minute accordingly.
42
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30,000
20,000;
10,000
100
200
300
400
500
600
DENSITY ALLOWABLE (Ib/cii-yd)
Figure 18. The maximum densities allowable in an 80 cu-yd trailer arc shown
at various empty trailer weights when a 16,000-lb tractor is used
and a 72,000-lb legal gross weight limit exists.
30
I
I
T
T
T
20
10
I
I
I
I
5000
10,000 15,000
•; EMPTY TRAILER WEIGHT
20,000
25,000
1 30,000
Figure 19. The maximum payloads allowable in an 80 cu-yd trailer are
shown at various empty trailer weights when a 16,000-lb Tractor
is used and a 72,000-lb legal gross weight limit exists..
43
-------
cj
«c
O-
«c
CJ
250
500 ' 750 1000
DENSITY ALLOWABLE (Ib/cu-yd)
1250
1500
Figure 20. The maximum densities allowable are shown at various trailer
capacities when the empty weight of the tractor-trailer rig is
40,000-lb and a 72,000-lb legal gross weight limit exists.
44
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300,000
CO
o
200,000
100,000
HAUL COST=$30 per trip
I
100,000 .200,000
ANNUAL TONNAGE
300,000
Figure 21. The total annual hauling cost from a transfer station can be significantly
reduced by maximizing the average payload per trip.
45
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Planning the size of a transfer station requires that expected
future solid waste quantities be estimated. To allow for future expan-
sion, necessary land must be available and provisions for easy additions
to initial buildings should be provided. Foundation work for future
expansion can usually be most easily done during initial construction.
Hauling and handling equipment for expanded operations should be acquired
as needed to prevent operation slowdowns. If a transfer station is con-
structed in a well-developed area, it may never be necessary for the
station to draw upon a larger population area unless a more distant dis-
posal site is used. An increase in volume, however, should be expected
over the years as the per capita waste generated increases.
Planning the size of a transfer system can only be attempted after
a study of local conditions is made. The choice of a system must first
be made to meet the needs and desires of the service area. The choice
should be based on consideration of the advantages and disadvantages
of each system as they relate to the specifics of the area. Such factors
as who will use the facility and the type of neighborhood in which it •
is to be located may have a great influence on the decision. Several
systems may appear basically equivalent. Hence, the preference of the
operating authority may have to determine which system best meets the
aesthetic or economical requirements of the area.
Once selected, the size of the transfer system must first be
determined so that the actual physical dimensions of the structure and
traffic areas can be planned. The expected daily waste quantities and
the round-trip time to the disposal site are the most important variables
46
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in planning the size of the system for the number of trailers, unloading
stalls, compactors, etc. After the daily waste volume and round-trip
travel time are known, it is relatively easy to determine the number of
trailers needed to handle the load. At least one trailer must always
be in loading position and an old tractor or other vehicle should be
available for moving the trailers into and out of loading position. A
fewer number of tractors than trailers is necessary since tractors should
not be idle at the transfer station. Storage provisions based on peak
load periods are necessary to prevent queuing problems with incoming
collection vehicles. The capacity of a transfer station depends on the
capacity of its least efficient element. For example, a sufficient
number of trailers may be available but a small storage area may sub-
stantially slow down the operation.
In summary, planning the size of a transfer station is not a diffi-
cult problem once a transfer system has been selected and the important
variables have been determined from a study of the area. A rule of thumb
is not available for planning the size of various elements of a transfer
system because a wide variation of conditions will exist in different
communities.
In the following paragraphs, each of the transfer systems within
the direct-dump and compaction categories will be discussed in detail.
Gravity Dumping from One Vehicle to Another - No Compaction. This
is the most basic and simple form of transfer and has been practiced for
many years in small operations, especially in the once widely practiced
hog-feeding operations. This system is employed where small volumes
. 47
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are handled and usually consists of an earthen or asphalt ramp from
which the unloading vehicles dump into a trailer located below. This
system is inadequate for most purposes and should not be considered
except possibly in rural locations where less than one transfer load per
day is expected. Unless a hopper is utilized, problems with spillage .
will probably arise. With special types of high-density waste such as
might be produced in an industrial process, this method may be entirely
adequate, however, because compaction would not be required to obtain
maximum legal payloads.
Gravity Dumping from One Vehicle to Another Followed by Load Leveling
and Compaction With a Backhoe. This method has become quite popular and
has been used in both small and large transfer stations. Basically this
method is the same as that above except that backhoes provide the
necessary leveling and compaction to obtain maximum payloads. This
system works well where most of the incoming waste comes from compactor
collection vehicles because little'additional compaction is usually
required to obtain maximum legal payloads. The backhoes used in this
system can be mounted either stationarily above the trailers or be self-
propelled vehicles that move from trailer to trailer (Figures 22 and 23).
This type of system has been used both in open-air operations and
enclosed operations (Figures 12 and 24). Incoming vehicles back up and
unload directly into the funnel-shaped hoppers located above the trailers
(Figure 25). The hoppers are designed large enough to prevent spillage.
The backhoe then distributes, compacts, and levels the transfer trailer
load as required. Backhoes are capable of exerting up to 10,000 Ibs
48
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Figure 22. The stationary backhoe used in many direct-
dump transfer systems is permanently mounted and serves
only a few loading hoppers.
L.
Figure 23. The self-propelled backhoe used in many direct-
dump transfer systems moves from hopper to hopper.
49
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Figure 24. The direct-dump transfer stations in King
County, Washington, are attractively housed under a steel
roof.
Figure 25. The loading hoppers utilized in direct-dump
transfer stations are used to funnel the waste into open
top trailers located one level below.
50 '
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of downward force on the waste depending upon size and can easily achieve
maximum payloads if most of the incoming material is precompacted in
collection trucks.
To avoid the problem of backing and maneuvering the transfer vehicles
into position under the hoppers, a drive-through arrangement is usually
employed. The unloading area can be at ground level with the transfer
vehicle loading positions excavated at a lower level; or the unloading
areas can be elevated with the transfer vehicles loading at ground level.
The existing terrain at the site may easily determine which method
requires the least construction. A typical traffic flow and plant lay-
out diagram is shown (Figure 26). Simultaneous loading of two transfer
vehicles and unloading of eight collection vehicles can be performed at
this facility.
To prevent queuing problems, the facility must be designed to have
a sufficient number of hoppers and trailers available to accept peak
incoming waste loads since storage is not easily incorporated into this
system. In special circumstances waste can be stockpiled on the loading
floor and later be placed into the empty trailers when the heavy incoming
.waste load subsides.
Many methods have been used to unload open-top trailers. The
cable pullout method is popular but somewhat inefficient. Cables are
crossed, and positioned before loading at the front of the trailer and
run along the sides all the way to the rear door. A tractor at the land-
fill is attached to the ends of the cables and pulls the load out, but
unless care is taken to place bulky material near the front of the
51
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en
no
TRANSFER VEHICLE
LOWER LEVEL
•> COLLECTION VEHICLES PATH
-* TRANSFER VEHICLES PATH
Figure 26. The traffic flow/ qnd plant layout of a typical direct-dump transfer station in which backhoes are used for compaction.
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trailer to provide a sweeping action, waste is often left in the trailer.
The cables must .also be manually repositioned in the trailer before it
can be reloaded. A similar but more efficient unloading method utilizes
£7
a steel cargo net that, ejects the. load by being ...pulled from the front
to the rear of the trailer. The same tractor and cable procedure provides
the ejection power. After unloading, the cargo net is repositioned in
the front of the trailer with electric winches and small cables.
Two unique methods for unloading open-top trailers are used on the
West Coast. The new transfer station in San Francisco utilizes a
transfer vehicle configuration consisting of a 73-cu-yd trailer in tow
of a 70-cu-yd body truck. Self-propelled hydraulic tippers capable of
tilting the trailers to a maximum of 70 degrees from the horizontal are
utilized in the unloading operation (Figure 27). The trailer is first
backed onto one tipper and unhooked, and the truck is then backed onto
the other tipper. After both are unloaded the truck drives off the
tipper, rehooks to the trailer, and proceeds back to the transfer station.
The tippers can move to any desired location on the landfill under their
own power. Unloading can be accomplished in six minutes. The tippers
are expensive ($72,000 each), however, and are not warranted unless a
large volume is handled.
King County, Washington, utilizes a unique transfer trailer config-
uration made up of a flatbed truck carrying two 42-cu-yd containers. At
the landfill, a self-propelled hydraulic scooper fitted with specially
designed arms picks up the containers and flips them for emptying
(Figure 28). The transfer vehicle stops on the road with the hydraulic
53
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Figure 27. Self-propelled hydraulic tippers are used for
open-top transfer vehicles in San Francisco.
Figure 28. A hydraulic scooper is used to unload transfer
vehicles in King County, Washington.
54
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scooper moving to the designed location for unloading the containers.
Unloading is accomplished in a matter of a few minutes. Once again, a
large volume is required to justify the use of this expensive ($130,000)
specialized machine.
This type of direct-dump transfer system has the following advan-
tages: (1) open-top trailers are lighter and capable of carrying larger
payloads than enclosed compactor trailers with their heavy reinforced
steel bodies and hydraulic equipment; (2) the simple loading method
prevents the possibility of having to completely halt operations as
would be required in a compactor system with enclosed trailers if a
breakdown occurred; (3) open-top trailers are usually cheaper in initial
cost and require less maintenance than enclosed compactor trailers;
(4) if incoming waste is precompacted in collection trucks, this method
will usually produce maximum payloads with the minimum amount of process-
ing; (5) drive-through provisions for loading transfer vehicles can
easily be incorporated into the design.
This type of transfer system has the following disadvantages:
(1) maximum payloads may be difficult to obtain when large amounts of
uncompacted waste are received; (2) unloading of open-top trucks is
more difficult and usually takes more time than required with enclosed
compactor transfer trailers and investment in expensive disposal site
unloading equipment may be required; (3) bulky items are not as easily
handled as in an enclosed compactor trailer system where considerable
hydraulic crushing force is available; (4) time is wasted in the place-
ment and removal of canvas or metal tops that are required to prevent
littering during transportation.
55
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Compaction Pit System. Other than utilizing an intermediate compac-
tion operation, this method is very similar to the preceding one. It
offers the advantage of providing storage as a routine part of the oper-
ation. Waste is dumped from the collection truck directly into a storage
pit. Here a crawler tractor crushes the waste before pushing it over a
ledge and into the hoppers located over the open-top trailers (Figure 7).
Backhoes then distribute and level the load but are not usually needed
to provide additional compaction.
This system is usually utilized when much of the incoming waste is
not precompacted in collection vehicles and when heavy traffic inflows
are experienced. The crawler tractor crushes and compacts the waste
and can quickly load large volumes of waste into the open-top trailers.
The storage pit allows many vehicles to unload simultaneously thus
eliminating long waiting lines. The preceding system, however, can
accomplish the same task more economically if most of the incoming waste
is from compactor collection trucks and if a large amount of storage is
not required to handle peak loads.
The new transfer station in San Francisco, with its well designed
plant layout and traffic flow patterns, is the best example of the com-
paction pit system (Figures 29 and 30). Currently about 2,000 tons per
day are being handled in a one-shift operation. Two transfer vehicles
are loaded simultaneously from the compaction pit with one crawler
tractor. The transfer vehicles rest on scales and as they fill up their
weights are instantly visible on a readout device, ensuring maximum
payloads without exceeding highway weight restrictions. The lightweight
56
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en
STORAGE AND
COMPACTION
PIT
COLLECTION TRUCK
-UNLOADING AREA
(UPPER LEVEL)
Ql p
TRANSFER VEHICLES
LOADING (LOWER LEVEL)
Figure 29. As indicated in this floor plan of the compaction pit transfer station in San Francisco, simultaneous
loading of two transfer vehicles and unloading of 17 collection trucks can be performed.
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TO DISPOSAL SITE
LEGEND:
•> TRANSFER TRUCKS.
-t> COLLECT!ON TRUCKS
Figure 30. As indicated in this plot plan of the compaction pit transfer station in San Francisco,
traffic flows smoothly with no interference between collection trucks and transfer vehicles.
58
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aluminum open-top transfer vehicles discussed previously are capable of
carrying 25.5-ton payloads. Seventeen incoming collection trucks-can
unload simultaneously. Incoming and outgoing traffic flow is smooth and
uninterrupted by bottlenecks because collection trucks and transfer
trucks have independent circulation patterns. The transfer vehicles are
not required to back into position as drive-through provisions are incor-
porated into the three-level design. The trailers can be loaded in
about six minutes. Several smaller compaction pit systems are also
operated on the West Coast. The San Francisco operation is described in
more detail in Appendix E.
The advantages of the compaction pit system are as follows: (1) a
convenient and efficient storage area is available that does not clutter
the unloading area; (2) uncompacted material is crushed in the pit
making maximum payloads obtainable without further processing; (3) the
open-top transfer trailers are lighter and capable of carrying larger
payloads than the enclosed compactor trailers with their heavy reinforced
steel bodies and hydraulic equipment; (4) the open-top trailers are
usually less expensive initially and require less maintenance than the
enclosed compactor trailers; (5) large volumes of waste can be handled
very quickly and many incoming vehicles can be unloaded simultaneously;
(6) drive through loading provisions for transfer vehicles can easily
be incorporated into the design.
The compaction pit system has the following disadvantages: (1) con-
siderable capital investment is required to construct the compaction pit
and to purchase the crawler tractor; (2) unloading of open-top trucks
59
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is more difficult''and usually takes more time than required with enclosed
V ' . . -
compactor transfer trailers and investment in disposal site unloading
equipment may be required; (3) time is wasted in placement and removal
of canvas or metal tops that are required to prevent littering during
transportation.
Internal Compaction Trailer System. In this system the transfer
trailer serves as both the compactor and the bulk hauler. A traveling -
bulkhead powered by a telescoping hydraulic cylinder is initially posi-
tioned at the front of the trailer to start the cycle. Waste drops
through a door located on top and near the front of the trailer to a
position immediately forward of the bulkhead (Figure 31). The bulkhead
then pushes the waste horizontally toward the rear of the trailer and
compacts it against the rear doors. The bulkhead is then repositioned
in the front of the trailer to receive a new charge of material. At the
disposal site the rear doors are opened and the bulkhead traverses the
trailer length and ejects the load (Figure 32).
This system can be set up in a variety of ways. For a small opera-
tion, the incoming vehicle simply backs into position and dumps its load
through a hopper and into the trailer (Figure 33). To eliminate the need
for backing into position, a drive-through operation is sometimes used.
The incoming vehicle drives over a door above the hopper and stops. The
hopper door is then hydraulically opened to receive the waste from the
collection vehicle (Figure 34). Holding hoppers can be used so that
the flow of waste into the trailer can be controlled. Often the load
from a collection vehicle may be larger than the volume the bulkhead can
60
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Figure 31. In a transfer trailer utilized in an internal
compaction trailer system, the waste is loaded through the
top sliding door via a hopper.
Figure 32. Horizontal compaction transfer trailers utilize
hydraulically powered bulkheads to eject the load out the
rear doors.
61
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Figure 33. The internal trailer compaction system is best
suited for low volume operations.
Figure 34. A drive-through system for unloading incoming
vehicles is sometimes utilized in some internal compaction
trailer systems.
62
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handle in one cycle. The holding hopper must therefore be capable of
receiving the entire load but must discharge only a portion into the
trailer.
Queuing problems with incoming vehicles can easily result with the
two operations above because only one incoming vehicle can be unloaded at
a time for each transfer trailer available. Therefore, in large-volume
operations this system requires that storage provisions be provided.
The overflow of incoming waste can be stockpiled on the unloading floor
and later pushed into the hoppers with a front-end loader. Attempts at
utilizing this system in a large-volume operation with only a few unload-
ing hoppers and no storage area will result in inefficiency.
Several methods for powering the hydraulic bulkhead system on the
trailers can be used. At the transfer station the hydraulic pump can
be located on a stationary unit along with an electric power source
(Figure 35). Quick-connect couplings are attached to the telescoping
hydraulic cylinder of the trailer which moves the bulkhead during the
compaction process. The hydraulic pump along with a gasoline engine
power source can be mounted permanently on the trailer itself (Figure 36).
This method is sometimes required in a small open-air operation when no
protection for a stationary unit would be available. Each trailer,
however, must be fitted with a pump and gasoline engine, and this extra
dead weight must be carried on each trip to the disposal site. The
gasoline engine also supplies the power for ejecting the load at the
disposal site.
63
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RETRACT RELIEr VALVE
WIRING CONDUIT
40 H.P MOTOR
COUPLING
GUARD
1
SOIENOID
CONTROL
VALVE
PILOT VAL
SECTION
TANK
BREATHER
FILTER
MAIN RELIEF
VALVE (red)
SUCTION
LINE
VALVE
Figure 35. At the transfer station, there can be a stationary
power source for operating the hydraulic system on an internal
compaction transfer trailer.
64
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Figure 36. An internal compaction trailer may be equipped
with a gasoline-engine-powered hydraulic system.
65
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If each trailer is not equipped with a gasoline motor, load ejection
at the disposal site can be accomplished in several ways. Each haul
tractor can be equipped with a wet-line kit which is powered by the
tractor engine through a power take-off system. At the disposal site,
quick-connect hoses are attached from the power take-off unit to the
hydraulic cylinder of the trailer for load ejection. Load ejection can
also be performed with a trailer mounted mobile power unit located at
the disposal site (Figure 37). This unit consists of a hydraulic pump
powered by a gasoline engine. The power unit is moved to the desired
unloading point and attached with quick-connect hoses to the hydraulic
cylinder on each trailer. The one power unit therefore takes the place
of the wet-line kits that would be required on each tractor, but unless
access to the disposal site is well controlled the risk of vandalism or
theft is apparent.
At any transfer station, drive-through access for transfer vehicles
is preferable to avoid the problem of backing and maneuvering the large
rigs into loading position. If a drive-through operation is not possible
because of peculiarities in site topography or location, sufficient
turnaround space must be provided to avoid wasted time in positioning.
The advantages of the internal compaction trailer systems are as
follows: (1) the system is easily adaptable to small operations where
incoming waste requires considerable compaction to achieve maximum pay-
loads because only a ramp and hopper are needed to transfer the load to
the trailer; (2) unloading of the trailers is very fast and efficient;
(3) the enclosed nature of the trailer does not require that canvas or
66
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en
Figure 37. A mobile hydraulic power source may be used for
unloading compaction transfer trailers at the disposal site.
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metal tops be handled with each loading and unloading; (4) maximum pay-
loads are easily and quickly obtained whether the incoming waste is in
a compacted or uncompacted state.
The disadvantages of the internal compaction trailer system are as
follows: (1) should the hydraulic bulkhead system fail, the trailer is
out of commission since there is no way of placing waste in the trailer;
(2) the extra dead weight of the hydraulic bulkhead system and required
reinforcement steel effectively reduce maximum payloads; (3) the initial
cost of compaction trailers is higher than that of open-top trailers and
they usually require more maintenance; (4) if the majority of incoming -
waste is precompacted in collection trucks, the heavier enclosed trailer
offers little advantage as maximum payloads can easily be achieved in
lighter open-top trucks with top tamping.
Stationary Compactor Transfer Systems. This system has gained wide
popularity, since it was introduced in 1961 and is the predominant transfer
system in use today. A transfer trailer is backed into position and
locked to a stationary compactor that is firmly anchored in a concrete
foundation (Figure 38). The hydraulically powered reciprocating ram of
the compactor forces the waste horizontally through a door in the rear
of the trailer.
Nearly all recent transfer station installations of this type utilize
an equipment package consisting of the trailers, compactors, hoppers and
sometimes the compactor feed equipment, all of which are purchased from one
manufacturer. The building foundation specifications and floor plan lay-
out are dictated largely by the particular equipment package being utilized.
68
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Figure 38. In a stationary compactor transfer system,
transfer trailers are locked to the stationary compactor
for loading.
Figure 39. The stationary compactor transfer system has
become very popular in small-volume operations.
69
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The stationary compactor system has been used in a variety of
different-sized installations ranging from small open-air single compac-
tor stations to.large enclosed multi-compactor plants. Small enclosed
operations have become very popular in many communities throughout the
country (Figure 39). The compactor chambers are always fed by gravity
from a hopper arrangement but the movement of waste from the incoming
trucks to the hoppers is accomplished in a variety of ways. In small
operations a storage area may not be required and incoming waste is
dumped directly into the hopper above the compactor (Figure 40). In
operations requiring storage the compactor can be fed with crane buckets,
conveyors, front-end loaders, and hydraulic push pits, alone or in com-
binations.
The front-end-loader charging method is a simple and inexpensive
method of providing storage. Waste is stockpiled on the floor and later
pushed into the compactor hopper with the front-end loader (Figure 41).
The conveyor feed method offers advantages of simpler one-level
building design and can be housed in a standard modular steel building.
Some incinerators have been converted to transfer stations by simply
placing a conveyor on the charging floor and utilizing the old furnace-
charging buckets as the conveyor feed (Figure ,42). In other plants one
section of the conveyor is placed at floor level and the incoming trucks
dump directly onto it (Figure 43). During peak delivery period, the
waste can also be dumped on the floor adjacent to the conveyor and pushed
onto the belt with front-end loaders.
70
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Figure 40. In this type of small volume transfer station, incoming solid waste
is dumped directly into the stationary compactor hopper.
Figure 41. In this type of transfer station, incoming solid waste is stockpiled
on the floor during peak.delivery periods and is then loaded
into the stationary compactor hopper with a front-end loader.
71
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Figure 42. In this incinerator that was converted to a stationary
compactor transfer station, the crane bucket is used
to charge the conveyor from the storage pit.
72
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Figure 43. When an inclined conveyor is used to charge the stationary compactor
hopper, a simple single level building design can be utilized.
Figure 44. In some transfer stations, hydraulic push-pits are used as both a means
of storage and as a means of loading the stationary compactor hopper.
73
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The hydraulic push-pit is another method developed to provide storage
capacity. Solid waste is fed automatically to the compactor by means of
a hydraulically actuated bulkhead (Figure 44). The incoming trucks back
up and dump into the pit, and when required, the bulkhead traverses the
pit horizontally and loads the compactor hopper. A central control
panel is used to actuate both the stationary compactor cycle and push-
pit bulkhead cycle. Two types of pits are used with the push-pit bulk-
head. The first is a concrete pit that is initially poured into the
floor foundation (Figure 45). The second type is a steel pit constructed
integral with the stationary compactor unit (Figure 46). The steel pit
is more flexible in that it can be moved to a new location if required
and requires only that an unloading level equal in height with the top
of the pit be available.
The stationary compactors used in this type of transfer system are
large heavy-duty units that can handle almost any material placed in
them (Figure 9). The range of specifications for transfer compactors are
included in Appendix C. The compactors are capable of easily producing
in place densities necessary to obtain maximum legal payloads but care
must be exercised to prevent overloading. Because of the large forces
produced by the compactor ram the trailers must be firmly anchored to
the compactor. Chains were formerly used to secure the trailers but most
new units utilize an automatic locking device that is released manually.
The large pressures also require that the walls of the trailers be
heavily reinforced to prevent splitting. This adds considerable weight
to the unit. The compactor does not force solid waste through the entire
74
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Figure 45. A permanent concrete push-pit system is sometimes
used for charging solid waste into a stationary compactor
hopper.
75
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~rm=n
~rrnq-*
~miq: "
Figure 46. This portable steel push-pit system
for charging solid waste into a stationary com-
pactor hopper is shown independent of the transfer
station to illustrate the construction.
-------
rear door of the trailer but through a smaller area equipped with double
dutch doors. At the disposal site the entire rear section is opened
and the ejection bulkhead pushes out the load (Figure 47).
Some trailers utilize the load-ejection bulkhead as a packing plate
during loading. The waste forced in by the compactor is compressed
against the bulkhead until enough pressure is obtained to force the bulk-
head slowly to the rear. In other systems, the bulkhead is not used but
remains in the front part of the trailer. Compaction is obtained only
when the trailer is nearly full and the last several cycles of waste are
forced against the preceding ones. Because nearly all the compaction
is obtained at the rear of the trailer with this system, horizontal'as
well as vertical reinforcing of the walls is required to handle the
pressures produced. Most stationary compactor systems utilize a light
on the control panel to indicate when a preset resistance is met by the
reciprocating ram. This warns the operator as to when the trailer is
nearly full. A booster cycle can then be switched on which increases
the hydraulic pressure several hundred Ib per sq in. The increased
pressure is used to force in the last compactor charge of waste. Opera-
tors of stationary compactor systems have indicated that care is required
in loading the trailers because fine material tends to drop from the
lip of the compactor at the rear of the trailer and cause overweight
conditions on the rear axle.
An electrically driven hydraulic system is used to power the sta-
tionary compactors. If hydraulic push-pits are used they are usually
driven by a separate electric motor. The hydraulic ejection bulkhead
77
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Figure 47. An ejection bulkhead utilized on a compaction
transfer trailer pushes the waste out through the rear
doors.
78
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of the trailer is driven either by a wet-line kit to the power take-off
of the tractor or by a stationary gasoline motor mounted on each trailer.
The stationary compactor transfer system requires that the trailers
be backed into position to be attached to the compactors. Therefore ample
turnaround space must be provided. Incoming vehicles must also back
into position to unload into the compactor hopper or into the storage
area.
In large stationary compactor transfer stations, traffic flow is
sometimes controlled with a colored lighting system. The compactor oper-
ator flashes a light to signal incoming trucks to a dumping stall. In
addition, transfer vehicle positioning is often done with tractors
specially designed only to move trailers around the yard (Figure 48).
The yard tractors move the full trailers to a pick-up area and replace
them with an empty trailer. The haul tractors can then spend all their
time moving between the station and the disposal site (Figure 49). They
leave their empty trailer in the designated area and pick up a full
trailer and drive directly back to the disposal site.
The advantages of the stationary compactor transfer system are as
follows: (1) maximum payloads can easily be obtained with uncompacted
or compacted solid waste; (2) unloading of the trailers is very fast and
efficient; (3) the enclosed nature of the trailer does not require that
canvas or metal tops be handled with each loading and unloading; (4) the
compactor can handle nearly all bulky material that can be placed in
the hopper because of the large hydraulic force available; (5) the
incoming waste usually receives minimum exposure because it is rapidly
pushed into the sealed trailers.
79
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Figure 48. Small yard tractors are often utilized for
moving trailers into and out of loading position.
Figure 49. Conventional tractors are used for hauling
transfer trailers to and from the disposal site.
80
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The disadvantages of the system are as follows: (1) should the
compactor fail, there is no other way of loading the trailer; (2) the
extra dead weight of the ejection bulkhead system and required steel
reinforcement effectively reduce maximum payloads; (3) the initial cost
of the trailers is higher than open-top types and they usually require
more maintenance; (4) a drive-through system for transfer trailer load-
ing is not possible with current compaction systems; (5) if the majority
of incoming waste is precompacted in collection trucks, the heavier
enclosed trailer offers little advantage as maximum payloads can be
achieved in lighter open top trailers with top tamping.
81
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CHAPTER III
TRANSFER STATION COSTS
The basic logic for economically justifying a solid waste transfer
operation was- presented in Chapter I. In the present chapter some
representative construction and operating costs will be presented based
on information gathered in a field survey of several transfer stations
throughout the United States. Unfortunately, in many cases data on
the owning and operating costs were nearly impossible to extract from
the existing accounting system. Various costs were interwoven and
combined witH costs incurred in solid waste collection and disposal
activities. The importance of accurate cost accounting cannot be
overemphasized as the existence of the transfer station is based
solely on economics. A cost accounting system is presented in Appen-
dix D. The two direct cost centers, namely> the Transfer Operations
Cost Center arid the Waste Transport Cost Center, developed in this
accounting system will be used in the following discussions of owning
and operating costs.
Construction Costs
Construction costs vary widely depending on locality, design and
site improvement requirements. Any conventional type of building con-
struction can be used to house the transfer facility once the desired
transfer system and size is determined. In addition to the building
itself, considerable expense for excavation and filling, foundations,
82
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utility provisions, access roads, fencing and landscaping is incurred.
Some types of transfer operations such as stationary compactor or com-
paction pit systems require more detailed foundation work thereby
increasing construction costs. If a site is not already owned, consid-
erable cash outlay for land may be required.
A wide variety of building types was encountered during the survey
ranging from none at all (open-air) to well-landscaped, aesthetically
designed concrete and steel structures (Table 9). It is difficult
to correlate initial cost to handling capacity. Although many of
these transfer stations are underutilized, a definite design capacity
is hard to place on any transfer station for several reasons. First,
a major concern in designing for size is to minimize the time expended
in unloading each incoming vehicle. Thus a sufficient number of
unloading spaces must be provided, but each vehicle requires one stall
whether it will unload 1 ton or 10 tons. If the facility is restricted
to use by a fleet of standard-sized packer trucks, the capacity can
be determined more easily. Second, it is not necessary for the waste
to be loaded as fast as it is brought in when storage is available. A
peak input period usually occurs in both the morning and afternoon,
but during slack periods the peak loads can be quickly reduced. In
addition, most transfer stations are seldom operated more than one
shift per day but are flexible in that overtime can be scheduled when
necessary to handle unusually heavy loads. Ultimately, of course,
the maximum capacity of a transfer station is limited by the maximum
rate with which the transfer vehicles can be loaded. For example, if
83
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TABLE 9
CONSTRUCTION COSTS OF TRANSFER STATIONS EXCLUSIVE OF LAND AND EQUIPMENT
Location
Detroit, Michigan
Hamilton, Ohio
Lancaster, Pennsylvania
Type
Stationary compactor
Stationary compactor
Stationary compactor
Year
Constructed
1970
1970
1968
Building
material
Brick and concrete
Steel
Steel
Yearly
tonnage
handled
350 ,000
3,800
120,000
Cost*
$ 863,420
115,000
160,000
King County, Washington
Algona
Bow Lake
Factoria
oo Houghton
•** Kent
Northeast
Renton
Orange County, California
Stanton
Huntington Beach
Anaheim
San Francisco, California
Seattle, Washington
Direct dump-backhoe tamping
Direct dump-backhoe tamping
Compaction pit
Compaction pit
1968 Steel roof, no sides
1960 Open-air
1966 Steel roof, no sides
1966 Steel roof, no sides
1960 Open-air
1969 Steel roof, no sides
1964 Steel roof, no sides
1961 Open-air
1963 Open-air
1966 Open-air
1970 Steel
29 ,000
57,900
57,800
44,200
21,700
66,800
42,300
181,195
136,022
206,996
177,000
65,000
102,000
100,000
31 ,000
173,000
124,000
347,000
212,000
350,000
550,000
*A11 costs are indicative of the year in which the facility was constructed.
To be opened in August 1971.
900,000
North
South
S.E. Oakland Co., Michigan
Topeka, Kansas
*•
Direct dump
Stationary compactor
1968
1966
1971 .
1968
Concrete
Concrete
Brick and concrete
Steel
190,000
160,000
160,000
26,000
900,000
700,000
1,500,000
160,000
- =•- -'.---,- •
-------
a stationary compactor can displace 10-cu-yd every 45 seconds, it
could theoretically handle 800-cu-yd per hour but only if a transfer
trailer is always in position and if the compactor can be fed contin-
uously at the rate of 800-cu-yd per hour. This ultimate capacity
is more difficult to determine in a direct-dump and compaction pit
system.
In trying to estimate the cost of a transfer station per ton of
handling capacity, difficulty is also encountered because of varying
aesthetic requirements. Considerable extra, construction cost will
usually result from building in a residential neighborhood.
In summary, the desired transfer system must first be selected.
This is followed by an estimation of the number of unloading stalls
required to handle the anticipated peak incoming traffic flow. Then
the necessary processing equipment to load the daily waste volume should
be determined. Finally, a building aesthetically acceptable to the
neighborhood and of dimensions suitable to house the operation should
be determined so construction and site development costs can be esti-
mated.
Construction cost figures for the type of transfer stations built
in King County, Washington show that many other costs in addition to
those for the structure itself are involved (Table 10). This station,
which is typical of the seven in King County, can accommodate about
12 vehicles unloading simultaneously and is covered entirely by a roof
but not completely enclosed (Figure 24). Backhoes are used for com-
paction in the two-level, direct-dump operation.
85
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TABLE 10
CONSTRUCTION COSTS OF A
KING COUNTY, WASHINGTON, TRANSFER STATION
Item Cost
Supervision, bond,, insurance $ 3,700.00
Excavation and filling 13,000.00
Asphaltic roads • 12,500.00
Fencing 9,700.00
Steel guard rails 2,800.00
Concrete walls 17,000.00
Concrete slabs 10,200.00
Reinforcing steel 8,800.00
Steel building 29,800.00
Roofing and sheet metal 12,500.00
Painting 2,500.00
Plumbing, sewer, drainage 14,700.00
Electrical wiring and lighting 3,000.00
Landscaping 12,600.00
Miscellaneous items 1,000.00
State taxes • 6,800.00
Architects and engineers fees 12,500.00
Total cost (except land) $173,100.00
86
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Equipment Costs
The equipment used in transfer stations falls into two major cate-
gories. The first is processing equipment which includes every device
utilized in the transfer process and varies from system to system. The
second is haul equipment which includes trailers, tractors, and unload-
ing equipment.
Processing Equipment. Processing equipment requirements vary from
none at all in the very simplest direct-dump systems to stationary com-
pactors used in an enclosed trailer system. Each system will be listed
below along with the processing equipment utilized.
Gravity Dumping from One Vehicle to Another - No Compaction. This
system usually requires the use of a hopper to avoid spillage. The
hopper should encompass the length of the open top transfer vehicle..
No actual mechanical equipment is required, but maximum payloads are
not obtained unless very dense waste is being handled.
Gravity Dumping from One Vehicle to Another Followed by Compaction
with a Backhoe. In addition to the hopper used in the preceding method
a mobile or permanently mounted backhoe is used. Small, permanently
mounted, electrically powered backhoes cost from $5,000 to $10,000 but
are seldom capable of producing the necessary compaction to achieve maxi-
mum payloads and serve mainly as load leveling devices. Larger electric
stationary backhoes capable of producing up to 8,000 Ib. of downward
force cost between $20,000 and $30,000. Diesel or gasoline-powered
mobile backhoes capable of exerting 8,000 to 10,000 Ib. of downward force
cost about $40,000. If a floor storage area is used in conjunction
87
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with the transfer system to handle peak loads the waste is pushed into
the hoppers with ordinary rubber-tired, front-end loaders.
Compaction Pit System. This system requires a crawler tractor
to compact the waste in the storage pit and push it into the open-top
trailers. The compaction pit system requires the use of crawler tractors
ranging in price from $30,000 to $70,000 depending on the size of the
operation. A backhoe similar to those listed above is also used to
distribute the loads but is seldom needed for compaction purposes.
Internal Compaction Trailer System. This system requires only a
hopper over the opening in the front of the trailer. The compaction is
achieved entirely within the trailer. These trailers cost from $23,000
to $26,000. If floor storage is used with the system the hoppers are
loaded with ordinary rubber-tired, front loaders.
Stationary Compactor Systems. The compactors are usually sold as
a package with various^sized hoppers available. With hoppers and all
accessories, the compactor units range in cost from $20,0,00 to $24,000.
The compactors can be fed in various ways as discussed in the previous
chapter. The cost of push pits starts at about $8,000, and the cost
of conveyor feed systems varies considerably depending upon such speci-
fications as length, width, and feed rate.
The cost of scales which might be used in any type of transfer
station varies widely with such specifications as length, capacity and
automatic features. As an example, the cost of a 30 ton capacity
scale that could be used for weighing incoming vehicles would be about
$10,000.
88
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Haul Equipment. Two basic types of haul vehicles are utilized in
truck-transfer operations. The first is the open--top trailer associated
with direct-dump and compaction pit systems; the second is the enclosed
trailer manufactured specifically for use with either an internal com-
paction system or a stationary compactor system. Both types of trailers
can be pulled by any conventional haul tractor.
Unlike the enclosed trailer with its built-in hydraulic bulkhead
unloading system, the open-top trailer requires that some unloading
system be designed to fit the operation. The simple crossed cable or
cargo net pull out systems require little capital expenditure but are
somewhat inefficient, and landfill tractors must leave their spreading
and compaction tasks to pull the loads from -the transfer trailers.
As discussed in the preceding chapter, the unique unloading systems
used in San Francisco and in King County, Washington require expenditures
for auxiliary machines. The hydraulic tippers used in San Francisco
cost approximately $72,000 each while the modified hydraulic scooper
of King County costs about $130,000.
Single, open-top trailers of 90 to 110 cu yd capacity cost $12,000
to $18,000 depending on construction material (i.e., stainless or
ordinary steel). Double trailer units with a combined capacity of
120 to 145 cu yd cost $12,000 to $20,000. The San Francisco aluminum
transfer vehicles consisting of a truck with a body of 70-cu-yd pulling
a 73-cu-yd trailer cost about $4.3,000 each. The flat-bed trailers used
in King County cost approximately $5,000 and each container about $3,000,
giving a total cost of about $11,000 for the 84-cu yd configuration.
89
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Enclosed trailers utilizing internal compaction list for $23,000
to $26,000 depending on capacity and the hydraulic power system used
(i.e., auxiliary gasoline engine or power take-off kit). Enclosed
trailers utilized with stationary compactors cost $18,000 to $22,000.
Trailers range in size from 60 to 80-cu yd. When several units are
purchased, bid prices are usually several thousand dollars less than
list prices.
Diesel haul tractors usually cost $16,000 to $17,000 each. All
transfer station authorities advised against the use of gasoline tractors
because of excessive fuel costs and maintenance problems.
Owning and Operating Costs
Total costs per ton for transfer and haul vary widely depending
primarily on wage rates, efficiency of operations and haul distances..
The range of costs for operations surveyed was $2.25 to $4.50 per ton.
This includes all costs incurred both in the transfer station operation
and in the long-haul operation (Table 11). Total costs were broken
down into transfer station operation and haul operation cost centers
when existing data permitted. It must be kept in mind, however, that
haul cost varies directly with the haul distance. No cost data were
obtained at several of the transfer stations surveyed because of
inadequate accounting procedures.
The cost of operating a transfer station varies with the degree of
service rendered and the type of financing used for the operation. If
the station is open to the general public and user charges are levied,
additional billing, accounting and weighing expenses are incurred. The
90
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TABLE 11
OWNING AND OPERATING COSTS OF TRANSFER STATIONS*
Location
Transfer
Station Cost
' ($/ton)
Haul Cost
($/ton)
Total Cost
($/ton)
Hamilton, Ohio
Lancaster, Pennsylvania
King County, Washington+
(average of 7 stations)
Orange County, California
$2.19
$2.38
$3.40 (est.)
2.23
4.57
Stanton -
Huntington Beach
Analieim —
San Francisco, California 1.88
Seattle, Washington 1.23
(both stations)
2.93
2.91
2.82
1,76 3.64
1.55 2.88
*These cost figures were obtained from interviews with the respective
operating authority.
1968 figures.
91
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most efficient and economical type of transfer station is that which is
run only as part of the collection operation of a city or contractor.
Waste loads and incoming traffic flow are relatively predictable and
billing services are not required.
As was discussed in the previous chapter, the efficiency of opera-
tion from the standpoint of carrying maximum payloads on each trip
can affect total costs substantially. Scales for weighing transfer
vehicles can therefore be a valuable tool in reducing haul costs because
both light loads and possible delays and fines resulting from overweight
conditions are eliminated.
From records available, a further breakdown of the costs proved
very difficult, but interesting information was gleaned from various
sources. For the seven transfer stations operated by King County,
Washington, some complete data for 1968 were obtained (Table 12). The
rather high costs can be explained in part by the fact that all seven
stations render a great deal of service as they are open to the public
seven days per week and are financed by user charges. Solid waste
from all seven stations is hauled to one landfill resulting in a long
travel distance from several of the installations. For all seven
stations the average round-trip hauling time is 89.2 minutes of which
73 percent is in travel time, 12 percent is unloading time and 15 per-
cent is loading time at the station.
The following costs pertaining to transfer vehicles were obtained
from Orange County, California, where open-top, double-trailer diesel
rigs are utilized in an open direct-dump system. For vehicles with
92
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TABLE 12
1968 COST BREAKDOWN FOR SEVEN TRANSFER STATIONS IN KING COUNTY, WASHINGTON
Transfer station operation cost center
Item Cost/ton ($)
Operation $1.67
Depreciation 0.12
Construction and modification 0.02
Overhead
Administrative 0.18
Facilities and equipment 0.20
Total 2.19
Waste transport cost center
I tern
Wages, salaries and benefits
Equipment operation
Equi pment mai ntenance
Depreciation
Overhead
Administrative
Facilities and equipment
Total
Cost/ton
$1.12
0.26
0.19
0.42
0.18
0.21
2.38
Cost/mile
$0.41
0.09
0.07
0.15
0.06
0.07
0.85
Cost/ton/mile
$0.025
0.006
0.004
0.009
0.003
0.004
0.052
Cost/ton/minute
$0.013
0.003
0.002
0.005
0.002
0.002
0.027
Extracted from King County Solid Waste Disposal For 20/20 Vision Volume II,
December 1970.
93
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less than 24,000 miles the fuel cost is $0.040 per mile; the deprecia-
tion is $0.070 per mile; and the maintenance, including tires, is $0.110
per mile. For vehicles with over 180,000 miles the fuel cost is $0.042
per mile, the depreciation cost is $0.048 per mile, and the maintenance
cost including tires is $0.160 per mile. These figures are based on
averages for the entire fleet. Transfer-vehicle fuel consumption for
all operations surveyed ranged between four and six miles per gallon.
The vehicles are usually amortized over a 6 to 8-year period.
94
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1962. p. 176-221.
Refuse transfer systems. Milwaukee, Heil Company. 21 p.
Zaun, W. L. The Orange County refuse disposal program. Santa Ana,
Calif., Orange County Road Department, 1965. 44 p.
Transfer cuts collection costs 20%. Refuse Removal Journal. 9(10); 28,
41, Oct. 1966.
Transfer plant operations for combined refuse pretreating with the
Heil-Tollemache pulverizer and baling the milled refuse. Milwaukee,
Heil Company, 1968.
Transfer reduces routes. Refuse Removal Journal, 9(9);30, Sept. 1966.
Transfer station saves nearly $100 a day. American City. 79(9) ; 25.
Sept. 1964.
Transfer stations assist refuse disposal. Public Works. 100(1) ;74-76.
Jan. 1969.
Transfer stations. In Solid waste disposal for the Omaha-Council
Bluffs; Metropolitan~Area Planning Agency, 1969. Omaha Henningson,
Durham & Richardson, p. Ill (4- 10).
102
-------
Transfer operations. In Refuse disposal study, chap.3. Regional
planning study No. 42. Akron, Tri County Regional Planning Commission,
Oct. 1965. p.17-19.
Truitt, M. M., J. C. Liebman, and C. W. Kruse. Mathematical modeling
of solid waste collection policies. 2 v. [Cincinnati], U.S. Department
of Health, Education, and Welfare, 1970. p.115-134, 185-188.
Vondrak, G. H. Transfer station shrinks the dead haul. American City.
83(2):100-101, Feb. 1968.
Washington county plans for transfer stations and burial. Solid Wastes
Management/Refuse Removal Journal, 14(8);72, 76, Aug. 1971.~
Wuest, K. L., and N. B. Hansen. World's largest solid waste transfer
station. Public Works, 102(2);61-64, Feb..1971.
19 miles not too long for Toulon. Public Cleansing, 55(2):75-78, 1965.
103
-------
APPENDIX A
LOCATION AND OTHER CHARACTERISTICS
OF TRANSFER STATIONS IN THE UNITED STATES*
State City or region
Alabama Decatur
California Alhambra
Beverly Hills
Chi co
Col us a
Doming uez
Fresno
Hollywood
Los Angeles
Lovelace
Lynwood
Orange County
Anaheim
Huntington Beach
Stanton
Oroville
Sacramento
San Francisco
Santa Barbara Co.
Santa Monica
South Gate
South Lake Tahoe
So. San Francisco
Wilmington
Colorado Colorado Springs
Denver
feaan°dPoe;^r?!!lbpe9an
1969, public
private
public
Under construction
1970, public
1970, private
1968, private
private
1950, private
1950, private
1950, private
private
private
municipal
1969, private
1963, private
1966, private
1966, public
1963, public
1961, public
1969, private
1959, private
1970, private
1967, public
1959, public
1959, public
Under construction
Under construction
1967, private
private
1965, municipal
Miles to
disposal; site
•
8
11
.
-
-
-
-
40
40
30
-
'
-
• ' -
• - •
25
13
15
25
- -
23
32
22
10
20
- -
• -
8
12
13
Annual
tonnage
-
2,000
27,000
-
-
-
33,000
500.
600
600
1,250
500
500
14,000
'
11,000
3,600
207,000
136,000
181,000
15,000
31 ,000
730,000
146,000
52,000
68,000
-
- •
6,250
400
30,000
104
-------
State
Connecticut
Delaware
Florida
Georgia
Illinois
Indiana
Kansas
Kentucky
Louisiana
Maryland
Massachusetts
Michigan
City or region
Middlebury
Orange
Westport
Kent County
Del ray Beach
Fort Lauderdale
Hollywood
New Smyrna Beach
Orange Co.
Palm Beach
Porapano Beach
West Palm Beach
Winter Park
Chamblee
Doraville
Forrest Park
Chicago
Chicago
Rosemont
Wilmette
Fort Wayne
Kokomo
Muncie
Kansas City
Topeka
Bellevue
Louisville
Gretna
Metairie
Baltimore
Arlington
Bedford
Boston
Medf ord
Birmingham
Dearborn
Detroit
State Fair
South-field
Flint
Year operation began
and ownership
1966, private
1970, private
public
public
public
-
public
1970, public
Under construction
public
private
public
1961 , public
1966, public
1966, Industrial
- •
private
private
1970, private
1965, public
1970, private
1969, private
1970, private
1970, private
1969, public
1969, public
1968, private
Under construction
1970, private
1969, private
1971, private
1969, public
1969, public
1969, private
1969, private
1971, public
1966, public
public
1970, public
private
private
1970, private
Miles to
disposal site
_
-
-
-
22
-
-
24
« **
10
-
7
-
16
12
—
-
—
• -
8
-
-
-
' '.
11
- •
-
-
• . -
—
-
•
14
- •
15
12 1/2
26
-
30
-
•
-
Annual
tonnage
4,000
7,000
20,000
-
-
-
15,000
220,000
—
-'
-
—
11,000
—
-
—
-
20,000
• '- •
-
-
-
18,000
•
- .
20,000
40,000
37,000
15,000
39,000
-
-
31 ,000
200 ,000
50,000
-
400,000
-
-
—
105
-------
State
%
Minnesota
Missouri
Nevada
New Jersey
New York
V
City or region
Highland Park
Lincoln Park
Monroe
Redford Township
Trenton
Wyandotte
Blaine
Grant Township
Minneapolis
Minnetonka
New Brighton
Osseo
So. St. Paul
Jefferson City
North Kansas City
University City
Reno
Bloomingdale
Bound Brook
Englewood
Ken il worth
Park Ridge
Pi scat away Tnwp.
Harrison
Hemps tead
Larchmont
Mamaronack
Mill ford
Mt. Vernon
New Rochelle
New York City
(9 Marine)
Port Chester
Rochester
West Seneca
Yonkers
'ear operation began
and ownership
_
1966, public
1970, private
1969, private
public
1964, public
1971, private
1971, private
1968, private
1971 , private
1969, private
1968, private
1969, private
private
1969, private
1967, private
1970, public
1963, private
1968, public
1966, public
1967, public
1969, public
1969, public
1966, public
1970, public
1969, public
1969, public
1969, public
1965, public
1969, public
-'
1937, public
1939, public
1939, public
1950, public
1954, public
1955, public
1955, public
1958, public
1965, public
1966, public
Under construction
1967, public
1969, public
Miles to
disposal site
_
25 .
-
15
' -
25
-
-
15
-
23
- -
17
-
6
25
15 . .
11
-
-
-.
-
-
14
-
12
-
-
-
-
-
13
22
20
17
27
23
20
25
16
27
-
-
-
Annual,
tonnage
_
20,000
-
'
- .
40,000
-
-
80,000
-
. '
-
-
—
16,000
5,000
24,000
-
-
-
-
-
-
100
- -
.
-
.-
-
-
-
272,000
333,000
90,000
294,000
355,000
343,000
355,000
170,000
225,000
-
-
'
-
106
-------
State
North Carolina
Ohio
Pennsylvania
Tennessee
Texas
Washington
West Virginia
Wisconsin
City or region
Kannapolis
East Cleveland
Euclid
Girard
Hamilton
Lakewood
Madison Twnp.
Parma
Pepper Pike
Rocky River
Shaker Heights
Warren
Youngstown
Erie
Lancaster
Pittsburgh
Norn's town
Washington Twnp.
Chattanooga
Johnson City
Abilene
Arlington
Dal 1 as
El Paso
McAllen
Sherman
Tyler
King County
Algona
Bow Lake
Factoria
Hough ton
Kent
N.E. Seattle
Renton
Seattle
Seattle North
Seattle South
Huntington
Marshfield
Milwaukee
Year operation began
and ownership
1970, private
1963, public
1967, public
1962, private
1970, public
1931, public
public
1956, public
public
1967, public
public
1967, private
Under construction
1970, private
1970, industrial
1968, public
1966, private
1967, private
1969, public
1964, public
1964 public
1960, public
1961, public
1963, private
1969, public
1962, public
-
1968, public
1967, public
1968, public
1960, public
1966, public
1966, public
1960, public
1960, public
1964, public
1968, public
1966, public
-
1970, private
1971, private
1971 , private
Miles to Annual
disposal site tonnage
-
-
-•
-
10
12
.
-
-
30
\
-
-
-
16
17
18
22
• -
18
24
5
7
5
29
14
-
•
7
21
17
16
25
20
36
12
22
13
7
22
-
—
_
' - -
13,000
7,000
36,000
31 ,000
- ' •
15,000
.
18,000
-
31 ,000
-
• •
_ '
100,000
62,000
-
-
27,000
5,200
156,000
94,000
12,000
36,000
.
-
.
.
30,000
60,000
55,000
45,000
13,000
68,000
44,000
190,000
160,000
-
_
'
-
107
-------
*This, list of locations is nearly complete; however a few installations
may be omitted, especially those that might have gone into operation
in late 1971.
108
-------
APPENDIX B
MANUFACTURERS OF. TRANSFER STATION EQUIPMENT SYSTEMS*
American Solid Waste Systems
63 South Robert Street
St. Paul, Minnesota 55107
Atlas Hoist and Body, Inc.
7600 Cote de Liesse Road
Montreal 376, Quebec
S. Vincen Bowles, Inc.
12039 Branford Street
Sun Valley, California 91352
Industrial Services of America
Tri-Pak Division
P.O. Box 21-070
7100 Grade Lane
Louisville, Kentucky 40221
Pak-Mor Manufacturing Co.
1123 S.E. Military Drive
P.O. Box 14147
San Antonio, Texas 78214
Dempster Brothers, Inc.
P.O. Box 3127
Knoxville, Tennessee 37917
Elgin Leach Corporation .
222 West Adams Street
Chicago, Illinois 60606
E-Z Pack Company
Division of Peabody Gallon
Gallon, Ohio 44833
The Heil Company
3000 West Montana Street
Milwaukee, Wisconsin 53201
Hobbs Trailers
609 North Main
Fort Worth, Texas.
76106
*Inclusion or exclusion of any manufacturer does not mean endorsement
or lack of endorsement by the Office of Solid Waste Management Programs,
EPA.
109
-------
APPENDIX C
SPECIFICATIONS FOR STATIONARY
COMPACTORS AND ENCLOSED TRANSFER TRAILERS
The following figures give a range of values found on currently manu-
factured equipment.
Stationary Compactors
Capacity 9-11 (cu-yd/cycle)
Cycle time. 28-48 (sec)
Total ram force 90,000-120,800 (Ib)
Hydraulic pump capacity 65-150 (gal/min)
Electric power unit 40-60 (hp)
Distance ram travels into trailer 13-50 (in.)
Hydraulic cylinder stroke 8-10 (in.)
Hydraulic cylinder diameter 30 ft long x 10 ft wide x
Dimension 5 ft high
Transfer Trailers
Capacity 60-75 (cu-yd)
Empty weight 22,500-27,500 (Ib)
Length 32-40 (ft)
Width 8 (ft)
Height 145-162 (in.)
Axle capacity 20,000-25,000 (Ib)
Ejection thrust 78,000-100,000 (Ib)
Ejection cylinder diameter 7-8 1/2 (in.)
Ejection cylinder stroke trailer length
110
-------
APPENDIX D
fox*
transfer station
operations
Eric R. Zausner*
The increasing costs and complexities of solid waste hand-
ling require new, more sophisticated management tech-
niques. Data on performance and the costs of operation and
ownership are essential for the use of these management
tools. A good information system is, therefore, a prerequisite
to effective management. Although cost accounting repre-
sents only one part of the total information system,.its design,
installation, and utilization can represent the most significant
step in the development of an effective solid waste man-
agement program.
Present information on transfer stations activities and asso-
ciated costs is both inadequate and nonstandardized. Fur-
thermore, the use of transfer stations will continue to ex-
pand as urbanization causes increased concentrations of
solid wastes and a scarcity of proximate disposal sites. The
proposed system provides a guide to the type and quantity
of information to be gathered, its classification, and the
method of collection. It is intended to be of use to municipal
or private personnel involved in transfer station operation
and ownership.
* Formerly Chief, Management Sciences Section, Operational Analysis Branch,
Division of Technical Operations.
in
-------
Installation of a cost accounling system can help the trans-
fer station manager control the costs and performance of
operation and also plan for the future. The system can be
implemented as presented or modified to meet the specific
needs and problems of the potential user.
The relationship of the transfer station to the total solid
waste management system is shown in Diagram I. The ac-
counting procedure can be utilized with all types of trans-
fer operations: compaction and noncompaclion, truck trans-
fer, and hauling by railroad cars or barges. In the last two
cases, some provision may be needed to account for disposal
charges.
System Benefits
Some of the more important advantages are:
1. The system facilitates the orderly and efficient collection
and transmission of all relevant data. In fact, most of the
data to be recorded are probably being collected already,
although perhaps only sporadically and inefficiently. Hence,
the added cost of installing the proposed system is minimal.
2. Reports are clear and concise and present only the amount
of data required for effective control and analysis. They can
be understood and completed easily by station personnel.,
3. The data are grouped in standard accounting classifica-
tions. This simplifies interpretation of results and comparison-
with data from previous years or other operations. This, in
turn, allows analysis of relative performance and operational
changes.
4. The system accounts for all relevant costs of operations.
5. Because the system detects high costs and identifies their
underlying causes, the supervisor can control expenses more
effectively. Similarly, performance and efficiency may be
monitored and controlled.
6. Accountability is superimposed on the system to indicate
who or what is responsible for the increased costs.
7. The data provided are in a form that aids in the short- and
long-range forecasting of operating and capital budgets. Re-
quirements for equipment, manpower, cash, etc., can be
112
-------
DIAGRAM I
SOLID WASTE MANAGEMENT SYSTEM
ROUTE
SERVICE
PRELIMINARY
HAUL '
TRANSFER
OPERATIONS
FINAL
HAUL "~
DISPOSAL
OPERATIONS :
i
T
COLLECTION
TRANSFER 'STATION
T
DISROSAL
BSWM (1/70)
-------
estimated lo aid budgeting and planning al all levels of
management. The data are also available for later evalua-
tion and analysis using operations research techniques.
8. The system, with only minor modifications, is flexible
enough to meet the varying requirements of different sizes
of transfer stations.
Cost Centers and Cost Allocation
The complexity of transfer station operations requires a
breakdown and description of operations to facilitate analy-
sis. In this presentation, the transfer station is assumed lo
consist of several interrelated suboperalions, each of which
is analyzed separately. These suboperations are called cost
centers because expenses are accumulated separately for
each of these functional activities (Diagram II). Analysis and
control are simplified if excessive costs or inefficiencies can
be traced to a functional activity or area of the facility.
The number of cost centers required increases as the size
and complexity of operations increase. Additional cost cen-
ters, however, require the collection of more data, and this
increases costs. In most cases, transfer operations would
include activities al ihe transfer slalion as well as the final
haul lo the disposal site. In this event, three cost centers
would probably be able to gather adequate information
wilhoul incurring excessive data collection costs. The Trans-
fer Operations cosl center and the Waste Transport cost cen-
ter are called direct cosl centers because they are directly
associaled with transfer and haul operations. Repairs and
Maintenance is an indirect cosl center. All repairs and main-
tenance expenses are accumulated in il and ihen allocated
lo ihe olher centers based on the amount ihey have incurred.
Because repairs and maintenance cosls can be a large per-
cenlage of tolal expenses, the use of a separate center focuses
attention on this critical area.
If railroad cars or barges are used, the cosl of the final haul
may not be included in a separate center but be accounled
for as a lolal charge for both final haul and disposal.
The cenlers classify cosls by one of two functions —opera-
lions and financing and ownership. Operating costs include
114
-------
DIAGRAM II
COST CENTERS AND COST ALLOCATION
Labor
Utilities
Parts and supplies
Overhead
Depreciation
Interest
P
P
E
R
A
T
I
N
G
C
0
S
T
TRANSFER
OPERATIONS
REPAIRS AND
MAINTENANCE
WASTE
TRANSPORT
TOTAL
•ANNUAL
COST
-------
labor, parls and supplies, utilities, external charges, and
overhead. Financing and ownership costs consist of depre-
ciation and interest. Table I summarizes these costs and
presents brief definitions of each.
There are many alternatives for actually allocating operat-
ing costs. A straightforward method for each type of expense
will be outlined. Labor charges should be allocated to the
cost centers based on the number of hours employees worked
in each and on their respective wage rales. Parts and sup-
plies include oil and gasoline as well as any materials used
for repairs and maintenance. Oil and gasoline costs are
assigned directly to the Waste Transport cost center because
they are incurred by its vehicles. All other parts and sup-
plies are allocated to each direct cost center after being
recorded in the Repairs and Maintenance cost center. Repair
charges levied by other municipal departments or private
firms are also allocated to the direct cost centers after being
recorded in the indirect cost center. Utility costs are incurred
by the Repairs and Maintenance and the Transfer Operations
cost centers. These expenses can be divided between them
on the basis of an engineering estimate or, for simplicity,
they can be assigned completely to the Transfer Operations
cost center. General overhead, which includes supervision,
administration and charges from other departments (payroll,
accounting) can be allocated equally to each cost center or
on the basis of the number of employees each has.
Finally, costs accumulated in the Repairs and Maintenance
cost center are allocated to the two direct cost centers based
on the expenses each has incurred. Their sum is the total
operating cost.
Capital costs are easily associated with each of the direct
cost centers. For instance, the capital cost of transfer vehicles
can be associated with the Waste Transport center, while the
purchase of scales can be included in the Transfer Opera-
lions cost center. Depreciation for each cenler can be calcu-
lated with these capital costs and estimates of their expected
useful lives. Total interest cosl can be allocated based on
the proportions of capital utilized in each cenler.
These allocation procedures are illustrated in Diagram II.
116
-------
TABLE I
SUMMARY OF COST TYPES
Labor (!)
Parts and supplies (2)
Utilities (3)
Overhead (4)
TOTAL OPERATING COSTS
Depreciation (5)
Interest (6)
TOTAL FINANCING AND OWNERSHIP COSTS
TOTAL COSTS
(1) Labor includes all direct wages, overtime pay and fringe benefits.
Fringe benefits include 4he costs of group insurance, .social security,
pensions, vacation benefits, etc.
(2) Parts and supplies include oil, gas, grease, repair parts, miscellaneous
supplies, etc.
(3) Utilities include electric, natural gas, water, etc.
(4) Overhead includes supervision, payroll and accounting services by
other departments, liability and property insurance, taxes; and external
charger;. External charges include audits, contractual services, etc.,
when they are performed by other municipal departments, private
contractors or consultants.
(5) Depreciation may be calculated using either straight line or accelerated
methods.
(6) Interest should represent actual costs of funds.
117
-------
The actual system is designed to facilitate the accumulation
and allocation of costs to the centers.
Forms and Reports
Information flows through the cost system by way of eight
reports (Diagram III). They transmit data collected in the field
for use at various levels of supervision and management.
The reports are most easily grouped into those that are
primarily used to collect data on operations and those that
are used to reduce and analyze for decision making and
control.
Reduction and presentation cannot be accomplished unless
all pertinent activities and cost information are recorded
daily. If this is not done, the data cannot be retrieved later.
Transfer station personnel, supervisors, and others involved
in operations primarily use Forms 1 through 4 to record the
data required.
Weekly labor report (Form 1). Daily entries of labor activ-
ity are recorded in duplicate at the site by the foreman or
supervisor. One copy is forwarded to the payroll department
for determining weekly wages. The supervisor or the ac-
counting department uses the other copy to compute the
total hours worked and to assign the lime and associated
costs to the cost centers.
Daily truck record (Form 2). This form shows the quanti-
ties, sources, and types of solid waste delivered to the trans-
fer station. The number, identification, and net weight of
outgoing transfer vehicles are also recorded. Each delivery
or departure is entered by the weighmasler. The form is
forwarded to the accounting department at the end of each
month. In addition to using recorded weight data to bill
public and private users later, the sources and types of waste
data are useful in special analyses of trends, compositions,
and distributions of solid wastes in the community.
Transfer station maintenance record (Form 3). This form
accumulates the activities and associated costs of repairing
and maintaining the transfer station. Entries are made only
when repairs are undertaken. These data are particularly
useful in anlyzing maintenance department performance,
118
-------
DIAGRAM III
REPORTS AND INFORMATION FLOW
Wage rates, utility bills,
charges from other departments
From purchase >" f X
records or / / Equipment and )
a survey
0
P
E
R
A
T
1
0
N
S
S V facility inventory /
(Wppklv labor V- .. ..' »
f . . \
(Station \
maintenance \ *
(Vehicle \ ^
maintenance y
A
C
C
0
U
N
T
N
G
D
E
P
A
R
T
M
E
N
T
r-1
(Operations \
summary r~
<
(
Vehicle
;
/ Total cost \
I summary I *
\ evaluation 1
"H
E
A
D
0
F
0
P
E
R
A
T
1
0
N
S
Key:
Report
119
Information
flow
-------
WEEKLY LABOR REPORT
FORM 1
TRANSFER STATION
IDENTIFICATION _
DATE:.
Employee ident.
o
TOTALS
Day 1
Cost
center*
X
Hrs.
Day 2
Cost
center
*
X
Hrs.
Day 3
Cost
center
X
Hrs.
Day 4
Cost
center
X
Hrs.
Day5
Cost
center
X
Hrs.
Day 6
Cost
center
X
Hrs.
Day 7
Cost
center
X
Hrs.
Individual
totals
Note causes and hrs. •
of absence, etc.
xxxxxxxxxxxx
Instructions: Transfer station supervisor to complete this form daily. List
all employees separately, including temporary help. "Hrs." refers to hours worked
daijy. At the end of the week forward one copy to the payroll department and
retain the original for further use.
*For this column TO, WT, or R&M could be used to indicate the cost center in
which each employee is working. For more accuracy, the following classifications
are suggested:
D (driver), VM (vehicle maintenance), SM (station maintenance), W (weigh-
master), F (foreman), S (supervisor), 0 (compacting equipment operator), C (clerk).
-------
FORM 2
DAILY TRUCK RECORD
TRANSFER STATION
SIGNATURE .
DATE:
No.
1
2
3
4'
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Truck ident.*
• «
TOTALS
Time
X
Incoming wastes
Source
X
Type
X
Weighted load
X
Weight empty
or tare wt.
X
Net amount of wastes
Incoming
Outgoing
Instructions: To be completed by weighmaster for each delivery of wastes or
departure'of transfer vehicle.
Symbols:
Source: R (residential), C (commercial), I (industrial)
Type: T (tires), G (garbage), etc.
*Truck ident. is #. of public truck; if private vehicle list name of company for
billing purposes. Also identify transfer vehicles by number, driver's name, and
type (barge, railroad car, etc.).
121
-------
FORM *
STATION MAINTENANCE RECORD
For Period
Date
Equipment or part
of facility repaired
Type repair
-
Mrs.
station
was down
Labor
hrs.
Parts
description
Labor
cost
Parts
cost
External
charges
Overhead
cost
<>
Total
122
-------
equipment availability, and equipment repair costs in the
Transfer Operations cost center.
Vehicle maintenance record (Form 4). This form accumu-
lates the activities and associated costs incurred in maintain-
ing the transfer vehicles. A separate sheet is kept for each
vehicle, and entries are made only when maintenance or
repairs are undertaken. These data are useful in analyzing
individual truck efficiencies and repair costs in the Waste
Transport cost center. The data on this form and those on
Form 3 represent the overall activity and costs in the Repairs
and Maintenance cost center.
Equipment and facility inventory (Form 5). This form is
completed when construction is finished or when the cost
system is first implemented. It is updated only when im-
provements or new equipment are constructed, purchased,
or sold. In addition to collecting the data required to calcu-
late depreciation for the period and allocating it to cost
centers, the form also summarizes the bond and interest
information needed to arrive at total costs of financing and
ownership.
Forms 6 through 8 are completed less frequently/ these
intervals depend on the type of information transmitted. To
be effective, certain types of control and analysis require
more frequent feedback than others. Forms 6 through 8 re-
duce the data contained in the first five as well as other
information available to the accounting department.
Operations summary (Form 6.) This report summarizes
system operations and its associated operating costs. The
report can be for the whole system or for individual stations,
since it is a critical cost control mechanism. The report should
be prepared monthly. The accounting department compiles
it and forwards copies to the supervisor and the head of the
sanitation department. The total unit costs presented, as well
as unit costs for the various centers, indicate where excessive
expenses were incurred. In addition, various measures of
efficiency are shown to isolate the cause or causes of high
operating costs. For instance, "tons/number of trips to the
disposal site" adequately measures truck utilization in the
Waste Transport cost center. This measure can help improve
scheduling and reduce costs.
123
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VEHICLE MAINTENANCE RECORD
FORM 4
TRUCK IDENTIFICATION
For Period ,
DATE
TOTALS
Odometer
reading
X
Type of service
or repair
X
Hrs.
down
Labor
hrs.
-.
Description
parts and supplies
X
Labor
cost
Parts
cost
External
charges
Overhead
(rate hrs.)
Total
cost
^
"
124
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FACILITY AND EQUIPMENT INVENTORY
Equipment
description
TOTAL
Capacity (cu. yd.)
X
Model No.
X
Model year
X
Manufacturer's
name
X
Date
of purchase
X
Purchase price
Estimated life
X
FORM 5
DatP / /
Annual
depreciation
Monthly
depreciation
ro
en
Facility description
Land
Buildings
Equipment
Site improvement
Other.
TOTALS
Description
(quantity, size, etc.)
X
Date put in use
X
New cost
Estimated
total life
X
Other comments
X
Annual
depreciation
X
Monthly
depreciation
X
Financing Data
Bond type
Face value
Premium or discount
Interest rate
-
Yearly interest*
Monthly interest
'Interest must account for effect of premium or discount on bond sale.
-------
FORM 6
OPERATIONS SUMMARY
For period.
to
TOTALS
TRANSFER
' OPERATIONS
COST
CENTER
WASTE
TRANSPORT
COST
CENTER
REPAIRS
AND
MAINTENANCE
COST
CENTER
Factor
Tons received
Average tons/day operated
Total operating cost
Total operating cost/ton
Labor cost/ton
Parts and supplies cost/ton
Utilities cost/ton
External charges cost/ton
Overhead cost/ton
"Cost center" cost/ton
Tons/hr. of operation
Percent volume reduction '
"Cost center" cost/ton
Tons/number of trips to disposal site
Labor hrs./ton
"Cost center" cost/ton
Repair and maintenance
cost/hr. of operation
Waste transport percent
Transfer operations percent
Percent time vehicles down
Percent time station down
Amount for this period
Percent
Budget
variance' from
• Budget last period
- '
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Vehicle evaluation report (Form 7). This form is optional.
It is nol needed if barges or railroad cars are used because
iransporl costs are incurred on a contract basis.
The data accumulated on this form represent the total and
individual costs of operating the transfer vehicles. Statistics
are accumulated separately for each piece of equipment, and
this allows efficiency and cost to be evaluated. The data
may also be used to determine when to sell or trade a vehicle.
Since this decision involves long-term assets, only quarterly
or semiannual reports are necessary. More frequent prepara-
tion would nol substantially improve decision making that
would minimize operating costs. It may be desirable, how-
ever, to prepare reports on a truck if it exceeds a given level
of repair charges. For instance, each vehicle's repair expenses
can be compared with the average for all the vehicles/ when
a vehicle exceeds this average by 25 percent or 50 percent, it
can be singled out for further analysis. The accounting de-
partment, which prepares this form, sends a copy to the opera-
tional supervisor and the head of the sanitation department.
Total cost summary (Form 8). All the activities and costs
associated with transfer system operations for a selected
period are compiled on this report from data available in
the Transfer System Operations Summaries and on the Facil-
ity and Equipment Inventory forms. The combined operat-
ing expenses and the depreciation and interest figures repre-
sent the total cost of operations for the period. The report
also summarizes the sources and amounts of revenues asso-
ciated with the system's operation. The accounting depart-
ment can complete this form quarterly or semiannually and
send it to the head of the sanitation department or his
equivalent.
Report Flow Summary
A brief summary may help to put the system in perspec-
tive. The personnel directly engaged in transfer activities
complete data accumulation forms daily and transmit them
periodically to the accounting department. The latter col-
lates the information and adds additional data it has on file
to complete summary reports on performance, activity, and
costs. These forms are then sent back to the supervisor for
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VEHICLE EVALUATION
FORM 7
GARAGE
For period.
.to
Equipment
identification
TOTALS
AVERAGES
BUDGET
Total
miles
X
X
Mrs. down
-
Hrs. down/total hrs.
X
Repairs and
maintenance cost
128
Fuel cost
Repairs and
maintenance
cost/hr.
X
Fuel
cost/hr.
-
X
Total
cost/hr.
X
Total
cost
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TOTAL COST SUMMARY
FORM 8
DISTRICT
For period ,
to
DATA
Tons of waste received
Total operating cost
Total financing and ownership cost
TOTAL COST
Operating cost per ton
10
Financing and ownership cost per ton
TOTAL COST PER TON
Public revenues (participating communities)
Private revenues (industry, etc.)
Miscellaneous revenues
TOTAL REVENUES
TOTAL REVENUES PER TON
NET COST (PROFIT)
NET COST (PROFIT) PER TON
FOR THIS PERIOD
BUDGET THIS PERIOD
CUMULATIVE
(YEAR TO DATE)
BUDGET
(YEAR TO DATE)
•
-
-------
conlrol purposes. In addition, selected summary reports on
lolal cosl and equipment performance are compiled and
forwarded lo the supervisor and lo his immediate superior.
System Utilization
Only with efficient and intensive utilization of the informa-
tion generated by the accounting system and its forms can
the additional lime, effort, and money required to implement
and maintain it be justified. The system's intensive use pro-
moles two major objectives — quality control and cosl conlrol.
Reduce costs must be accomplished without degrading oper-
ating quality. Similarly, quality is interrelated with the costs
of obtaining it.
All ihe factors thai affect the quality and effectiveness of
transfer system operations can be translated into costs: Cosl
conlrol does not call for economizing at the expense of qual-
ity. On the contrary, once an acceptable level of operations
and costs has been achieved, the system can help the super-
visor maintain it.
Effective conlrol requires timely recognition and assign-
ment of responsibility for any increased costs. Comparing
unil costs (cosl per ton of waste transferred) wilh the current
budget and thai for ihe corresponding period of the preced-
ing year helps pinpoint excessive expenses. This approach
facilitates the analysis of costs, independent of changes in
the level of activity. Cost center breakdowns help single
out the factor or person responsible for increased expendi-
tures, and this allows corrective action to be initiated.
P0352
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APPENDIX E
SITE SURVEYS
Several selected transfer stations were surveyed during the study
to observe the operation of the various types of transfer systems.
Interviews .with operating personnel were conducted and all available
information on buildings, equipment and costs was gathered. As mentioned
previously, very little cost information was obtained from some of the
facilities because of poor cost accounting and record-keeping. A general
description and summary of information follows for each site visited.
San Francisco, California
t
This privately owned transfer station was opened in November, 1970
to reduce the haul costs to a sanitary landfill site located 32 miles
south of San Francisco near the community of Mountain View. A solid
waste disposal crisis had developed when rail haul contract negotiations
for transport to a remote desert landfill site had broken down. Mountain
View needed tremendous volumes of fill material to continue development
of its 550 acre recreational park adjacent to San Francisco Bay, and
made a proposal to accept all of the solid waste of San Francisco for
approximately five years. In light of its pressing needs, San Francisco
accepted the offer as an interim measure to permit exploration of other
options for a permanent solution.
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The new transfer station was designed to handle approximately 5,000
tons per day over a 24-hour period. Currently, however, it is averaging
about 2,000 tons operating 9 to 11 hours per day. The two largest
collection contractors in San Francisco haul nearly all the residential
solid waste and have joint ownership of the transfer station with a
landfill company and an equipment company under the name of Solid Waste
Engineering and Transfer Systems (SWETS). The facility is not open to
the general public but serves only compactor trucks and various indus-
trial vehicles. Users pay a fee of $6.55 per ton to cover all costs
associated with transfer and disposal.
The transfer station utilizes a compaction pit system and has a
storage capacity of about 4,000 tons in the pit. Seventeen incoming
trucks can unload simultaneously, and an entrance and exit door is avail-
able on each side of the pit for smooth traffic flow (Figures 29 and 30),
Unloading requires five to eight minutes from the time the vehicle
enters the site until the time it leaves. A peak traffic load of about
100 vehicles per hour is easily handled without excessive delay.
A 200 x 180 ft clear span steel building equipped with a ventila-
tion and sprinkling system encloses the unloading area. Two transfer
vehicles are filled simultaneously in the loading area attached to one
side of the building. The transfer vehicles have drive-through access
and can be loaded in about five minutes; an unloading level, a storage
level and a transfer vehicle loading level are utilized (Figure 29).
A D8 Caterpillar tractor is used in the storage pit to compact the
waste and push it into the hoppers where it then falls into the open-top
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trailers. Originally, it was thought that two tractors would be
necessary, but one tractor has been handling the 2,000-ton-per-day load
in about 10 hours. An electric-powered hydraulic backhoe is mounted
stationarily above each trailer to distribute and level the load. Maxi-
mum legal payloads have been obtained without utilizing the backhoes
for compaction. Each transfer vehicle rests on an electronic recording
scale while being loaded. This enables the backhoe operator to see
exactly how much weight is in each vehicle at all times.
The transfer vehicles are specially designed aluminum body units;
each consists of a truck with a 70-cu-yd body towing a 73-cu-yd trailer.
The total weight of the rig is about 26,000 Ib allowing 25.5-ton pay-
loads to be carried on the five axles. This is the largest payload
carried by any transfer vehicle in the United States. Fuel pumps are
located in the loading area to permit refueling of the transfer vehicles
while they are loading. About 2 hours are required to cover the 64-mile,
round-trip distance to the disposal site. This includes unloading time
which requires a minimum of 6 minutes. Most of the route involves
travel on the Bayshore Freeway.
Two self-propelled tippers are located at the landfill for unloading
the truck-trailer combinations. The trailer is backed onto one tipper
and the truck uses the other. The waste slides out the rear doors as
the truck or trailer is hydraulically raised to a near vertical position
(Figure 27). Each of the 17 transfer vehicles makes about four trips
per day to the disposal site.
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All incoming vehicles are weighed on a 35-ft scale located in front,
of the plant. Both this scale and the two 65-ft scales on which the
transfer vehicles are weighed are automatically tied into an IBM system
for recordkeeping and billing purposes. A 6,000-sq-ft maintenance
building for minor repair work and servicing is also located on the site.
The following building and equipment cost figures were obtained in an
interview with the general manager of SWETS. .-,.-,
Building proper $550,000
Maintenance building & scale house 40,000
Site development 300,000
Scales 65,000
Total building cost $955,000
Transfer vehicles 17 @ $43,000 $731,000
Landfill tippers 2 @ 72,000 144,000
Compaction tractors 1 @ 65,000 65,000
Backhoe 2 @ 21,000 42,000 --.'•-
Total equipment cost $982,000
Of the $6.55 per ton charged for incoming solid waste, $3.64 is
allocated for the transfer operation. They estimate that $1.88 per ton
goes for transfer station operation and $1.76 goes for the haul operation.
The remainder of the $6.55 per ton goes to the disposal operation.
A total of 23 men are employed in the operation; 16 are drivers
and the remainder work at the transfer station. Labor rates are high in
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the area and with fringe benefits annual labor costs are roughly $400,000
for a 45-hour week.
The entire operation has been running smoothly. The open-top
trailer and compaction system was chosen over a stationary compactor
system because of the speed with which the compaction tractor can load
the waste and because the lighter trucks can carry larger payloads. The
one compaction tractor and two backhoes effectively replace the six to
eight stationary compactors that would be required with that type of
system. The additional investment in landfill unloading equipment, how-
ever, was required. A comparison between a large-volume compaction pit
system and large-volume stationary compactor system is included in
Appendix F.
Seattle. Washington
Seattle opened its South Transfer Station CSTS) in 1966 and added
the North Transfer Station (NTS) in 1968. Both stations utilize the
same design and incorporate a user fee system. Solid waste disposal is
operated as a self-supporting utility in Seattle but private haulers
handle all collection. The Solid Waste Utility owns and operates the
transfer stations and the sanitary landfill. Transfer station fees which
also cover disposal are as follows: Loads from passenger cars without
trailers are free for city residents and $0.50 per load for non-city
residents. The minimum load charge for cars with trailers and all other
vehicles is $1.25; bulk solid waste from private collectors and industry
is charged at $4.50 per ton.
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The transfer stations of the city of Seattle are unique in that
separate provisions for unloading and processing have been made for
incoming compacted and uncompacted wastes. Eight compactor collection
trucks can simultaneously unload directly into the open-top transfer
vehicles via a hopper, and a rubber-tired mobile backhoe is used to pro-
vide any necessary compaction and load leveling. Uncompacted waste is
unloaded into a compaction pit where it is compacted by a track dozer
and then pushed into an open-top transfer vehicle. About 10 vehicles
can unload simultaneously in this area. Two trailers are loaded simul-
taneously from the direct-dump operation and one trailer is loaded from
the compaction pit area. One backhoe serves all three trailers. The
trailers are backed into position by small yard tractors to prevent
the long-haul tractors from being tied up in the switching operation.
No particular transfer vehicles are permanently assigned to either
station but the haul operation is well coordinated to provide dispatch-
ing efficiency.
A total of 38 open-top 95-cu-yd transfer trailers and 18 haul
tractors serve the two stations. The rigs travel about 44 miles round
trip from the NTS and 25 miles round trip from the STS. Approximate
round-trip times are 2 hours and 1.5 hour respectively including unload-
ing. Pneumatically-operated steel lids cover the load during
transit and the waste is pulled out through the rear with a cargo net .
and cable system. A landfill tractor provides the ejection power and
the cables and net are repositioned with two small electrical winches.
The maximum legal weight limit is 73,280 Ib so the rigs which weigh
about 32,700 Ib can carry slightly more than 20-ton payloads.
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In 1970 both stations handled a total of 17,704 loads, each weigh-
ing approximately 20 tons for a total of 354,000 tons. Falling economic
conditions in the Seattle area have reduced this from a high of 19,164
loads in 1969. The best day for the NTS in 1970 was 760 tons and for
the STS, 708 tons. Currently the NTS averages 700 tons (35 loads) per
day and the STS averages about 600 tons (30 loads per day) Monday through
Friday. Approximately 200 to 250 tons (10 to 12 loads) come out of
both stations on weekends. Each station was designed with an ultimate
capacity of 300,000 tons per year.
Both transfer stations are well landscaped and fenced, and incor-
porate an attractive concrete building design. The NTS is located on
about 4-1/2 acres of land and the STS occupies about 7 acres, but the
city feels that 4-1/2 acres is too small to permit easy maneuvering.
The NTS is located in a residential area and presents a completely
unoffensive appearance; one condition of its operation, however, is that
all waste must be removed from the site at the close of each day. The
NTS is open 9 hours per day on weekdays and 10 hours on Saturday; the
STS is open 24 hours per day Monday through Friday, 17 hours on Satur-
day and 15 hours on Sunday. Hauling takes place 6 days per week with
storage on Sunday. Because of the stipulation that waste be removed
from the NTS at the end of each day, all storage must take place at
the STS.
Approximate capital costs associated with buildings and equipment
are:
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North Transfer Station building and $900,000 ; . .
development cost exclusive of land
South Transfer Station building and $700,000
site development exclusive of land
Vehicle washing center at South $ 80,000
Transfer Station
Transfer trailers $ 10,000 each
Haul tractors $ 17,500 each
Compaction pit tractors $ 65,000 each
Compaction backhoes $ 31,000 each
Yard tractors $ 13,800 each
A detailed analysis of owning and operating costs was not possible
because of the complex accounting system used. The city presented the
following total cost breakdown:
Total haul cost for both stations $1.55 per ton
Transfer dost at North Transfer Station $1.23 per ton
Transfer cost at South Transfer Station $1.95 per ton
The higher cost at the STS can be attributed at least partially to
the cost of the vehicle-washing center and the lower total tonnage
handled.
The entire Seattle operation was impressive. The problem of pro-
viding service to all types of incoming vehicles was overcome by incor-
porating both the compaction pit and the backhoe direct-dump transfer
systems. In addition, the NTS has been located in a residential area
with few complaints. Considering the very attractive design and the
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extra expense of incorporating a user fee system, the operating costs
are very reasonable.
King County, Washington
The King County transfer station system was started in 1960 to
handle wastes generated in Xing County outside the city limits of Seattle.
Three open-air, direct-dump, two-level stations were initially constructed.
The last four were constructed during the 1960's and incorporate an
aesthetic design with gable roof steel construction (Figure 24). The
buildings are not entirely enclosed but can be very acceptably located
near residential neighborhoods. In 1968, the N.E. transfer station was
converted to the newer design leaving only Bow Lake and Kent with open-
air installations. In all, the seven transfer stations have eliminated
15 previously used open dumps.
All seven stations utilize a direct-dump and backhoe transfer system.
The four new stations and the modernized N.E. station have permanently
mounted backhoes while the open-air installations utilize rubber-tired
mobile backhoes. Before the incorporation of the backhoes for compac- '
tion, payloads were considerably less than what the 73,280-1b gross
vehicle weight permitted. Within 120 days after installation, the cost
of the backhoes was amortized because of savings realized from hauling
fewer loads. User fees have been instituted to partially finance the
operations, but fees are assessed on an estimated yardage basis since
no scales are available.
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Transfer vehicle design has undergone a number of changes since'
operations began in 1960. Initially, open-top trailers of 90-cu-yd
capacity were used. They were unloaded by a hydraulically operated
conveyor chain device which proved inefficient as 20 to 25 minutes were
required to unload each trailer. An open-top 88-cu-yd side dumping
trailer was then adopted. It could be unloaded in 3 to 5 minutes, but
high maintenance costs and tire-wear rates were incurred because it had
to be pulled across the waste it discharged. Currently a very satisfac-
tory container concept is being used which consists of two 42-cu-yd
steel containers carried on a flat-bed trailer. At the landfill, a
hydraulic scooper lifts, empties, and replaces the containers in about
three minutes and the transfer rig never leaves the temporary roads on
the landfill site (Figure 28). The container flat bed trailer configu-
ration is considerably cheaper ($10,000) than most other types of
transfer trailers; the hydraulic scooper for unloading, however, is
priced at about $130,000 and a large transfer operation is required to
offset this cost. King County operates 48 transfer trailers and 14
tractors.
The only problem encountered at the newer stations is the station-
ary backhde size. The authority plans to replace the small $5000 units
with a heavier design to obtain better compaction. All waste is hauled
to the Cedar Hills sanitary landfill site where a complete maintenance
facility is located for immediate repair and servicing of all rolling stock.
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A breakdown of operating costs for King County operations was pre-
sented in Chapter III along with a listing of each of the seven stations,
their initial cost, year constructed, and volume handled. A breakdown
of construction and site development costs for a typical facility was
given in Table 11.
King County transfer and haul operations are incurring relatively
high costs. The system was designed, however, to eliminate open dumps
and provide county residents with convenient disposal points. The added
expense of their user fee system combined with the high haul cost from
some of the distant transfer stations are largely responsible for the
high overall cost. The authority plans to streamline the operations and
improve the efficiency of the entire seven transfer station systems.
Lancaster, Pennsylvania
The Lancaster transfer station is an example of a stationary com-
pactor system incorporating a package design of a manufacturer which
consists of trailers, compactors and hydraulic compactor feed equipment.
The transfer station, which opened in 1968, serves 150,000 people in
Lancaster and six surrounding townships and operates on a user-fee basis.
The transfer fees are:
Automobiles $0.75
up to 500 Ibs 1.00
500-750 1.25
750-1000 1.65
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1000-1250 2.05
1250-1500 2.45
1500-1750 2.85
1750-2000 3.20
16<£ per TOO Ib over 1 ton
The.operation consists of two stationary compactors which are fed
by two hydraulic push pits, each having a storage capacity of 100-cu-yd.
Large trucks usually dump directly into the two compactor hoppers while
small vehicles dump into the push-pits from one of six other unloading
stalls. During peak periods, trucks can be handled at the rate of
about 2-1/2 minutes each. The movement of material from each push pit
to the compactor hopper is regulated by an operator who also regulates
the stationary compactor operation. The control booth for the two
operators is located between the two pits. These operators also regulate
a water-spray dust control system and application of deodorizer and in-
secticides.
Two of the 65-cu-yd trailers are backed up to the compactors and
loaded simultaneously. Compaction does not occur within the trailer
until it is nearly filled. Communication between upper and lower levels
is by a buzzer system. The transfer trailer rigs weigh 39,000 Ibs so
that with the 72,200-lb legal load limit, a payload of approximately
17 tons is carried. Once at the sanitary landfill located 17 miles
away, the trailers are unloaded with a hydraulic push-out blade powered
from the power takeoff on the tractor. The total round trip requires
about 1-1/2 hours.
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A total of seven enclosed trailers and four tractors are used in
the hauling operation. Two open-top trailers are also used to haul
bulky noncorapactable material. The bulky waste is dumped directly in the
trailers from a ramp. A total of nine people are employed to handle the
station and hauling duties: one weighmaster, two compactor operators,
two laborers, three drivers and one foreman. The station is usually
open 9-1/2 hours per day 6 days per week.
The main building is 100 ft long, 40 ft wide, and 20 ft high and
is located on 2.6 acres. A scale house and an air-conditioned office are
also located at the site. The following capital cost information was
obtained from the supervisor:
Land $ 17,500
Buildings and scale house 160,000
Equipment
Scale 1 @ $9,500 9,500
Compactors 2 @ 17,500 35,000
Push pits 2 @ 7,500 15,000
Closed trailers 7 G> 17,500 122,500
Open trailers 2 @ 5,000 10,000
Tractors 4-0 16,500 66,000
Equipment subtotal $258,000
Total $435,500
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The station is currently handling about 400 tons per day. From
July 1969 to July 1970 a total of approximately 100,000 tons was handled
through the station. The total transfer and haul cost was $2.23 per
ton with no further breakdown available, the haul cost is estimated to
be, however, under $1.00 per ton.
The overall operation is run very efficiently and the equipment has
presented no major maintenance problems. The supervisor indicated the
only change he would make if 'he could redesign the plant would be to
incorporate a larger storage volume.
Hamilton, Ohio
The transfer system in Hamilton, Ohio, is identical to the system
utilized in Lancaster, Pennsylvania, except for size. The same type of
equipment is used but only one compactor and a push pit arrangement have
been installed. The footings, however, have already been laid for
future expansion to a two-compactor system.
A population of about 80,000 is serviced by the new transfer
station. Most of the eight 20-cu-yd compactor trucks owned by the city
unload at the facility twice a day. Operating hours are 8 a.m. to
6 p.m., Monday through Saturday. During the first few months of opera-
tion daily tonnages have ranged between 100 and 140 tons.
Work is staggered so that seven different employees work a 40-hour
week. In addition to the foreman, two laborers and four drivers are
employed. Four 75-cu-yd trailers and three tractors are used in the
haul operation. One of the tractors is used as a spare and to move
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trailers around the yard. The round-trip, 20-mile haul distance usually
required about two hours with unloading time. Approximately 19 ton
payloads are legally carried on the five-axle rig.
A 40 x 60 ft steel building houses the operation (Figure 39). Other
than the small room for the compactor controls, no office is available.
Total land area is about 1-1/4 acres. The approximate capital costs
are:
Building
Steel structure $20,000
Concrete 70,000
Miscellaneous 25,000
$115,000
Equipment
Stationary compactor and
hopper $38,800
Push pit 15,000
3 tractors 45,000
4 trailers 75,200
2 PTO's 2,000
Portable hydraulic power
source 4,000
$126,200
Total $280,000
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At the time of the interview, data on owning or operating costs, .
were not available. Based on a rough estimate, the total cost would be
about $3.40 per ton. The city is very pleased with the operation and ,.
no significant problems have been encountered.
Denver, Colorado
The Denver transfer station was opened in 1965 to handle the waste
from three of the 11 districts of the city. After 1969 it was determined
that wastes could be handled more cheaply by hauling directly to smaller
landfill sites operated by suburban communities instead of transferring
and hauling to the Lowry disposal site located 18 miles from the transfer
station. The transfer station will be reopened when nearby landfill
sites are filled and more transfer stations may be built.
The internal compaction trailer system incorporated a drive through
design so backing incoming collection trucks into unloading position was
not required. After a truck drove over the hopper trap door, the door
opened and the load was discharged into the hopper located over the
trailer (Figure 34). Once in the trailer, the hydraulic bulkhead com-
pacted the waste against the rear doors in cycles. Two unloading hoppers
were available but the city was dissatisfied with the system because of
queuing problems that developed with incoming trucks. The city feels
that storage provisions will definitely be incorporated into any future
transfer station designs.
The facility was open 8 hours per day, 5 days per week and was used
only by Denver's residential compactor trucks. A total of seven men
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were employed at the station: three drivers, one shuttleman, one clean-
up man, one machine operator, and one foreman.
A fleet of six 60-cu-yd trailers and three tractors were utilized.
The hydraulic compacting bulkhead system in the trailer was powered by
a stationary e1ectric source during the loading operation and by the
power take-off of the tractor during unloading. The five-axle empty rigs
weighed 37,500 Ibs and 15-ton payloads were carried, which made the
operation somewhat inefficient. In 1969 a total of 191,000-cu-yd was
processed, which was estimated to amount to 38,200 tons.
An attractive concrete building housed the operation with office
and restrooms available (Figure 14). The entire area is fenced and
presents a very pleasing appearance.
Cost information was very sketchy because depreciation was not
routinely figured into the overall costs, and repair and maintenance
were contracted out. No estimate on cost per ton was available. A total
capital cost of $650,000 was incurred but this includes a vehicle main-
tenance center located at the site. The three tractors cost $17,000
each and the trailers were $15,000 each. Other capital cost breakdowns
were not available.
Topeka, Kansas
A transfer station was opened in Topeka in 1968 in an effort to
reduce the overall solid waste budget of the city. The transfer station
is located only a few miles west of the city limits, and hence the sta-
tion is not utilized on days when route collection is on the west side.
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The transfer station is used only by city trucks and has no weighing
system available.
The two-level, single stationary compactor system is housed in a
steel building. Each incoming vehicle must back up and dump directly into
the compactor hopper as no storage space is available. Three 75-cu-yd
enclosed trailers and three tractors are used in the operation. The
round-trip distance to the landfill is approximately 20 miles and
requires about one hour including unloading time. The five-axle rig
weighs 39,000 Ibs and with the 73,280 Ib legal load limit, 17-ton pay-
loads are obtainable.
Six men are employed at the transfer station: three drivers plus
one relief, one laborer and the supervisor. The station is open only
foyr days a week and from 6 to 12 hours per day as required. From 100
to 120 tons per day are hauled from the transfer station giving a yearly
total of approximately 25,,OQO tons. No accurate tonnage records are
kept.
Very little cost information was obtained. The following approxi-
mate capital cost breakdown was given,
Equipment
3 tractors $43,400
3 trailers 65,300
1 compactor and hopper 23,200
$131,900
Building and site development 168,000
Total $300,000
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No owning or operating costs were obtained as they are not broken
down in the total collection and disposal accounting system of the city.
Considering the initial investment, the low overall tonnage handled and
the close proximity of the landfill site, it is questionable whether
this transfer station can be justified economically.
Orange County, California
In 1959, Orange County adopted a master plan for solid waste disposal
which established the concept of solid waste transfer combined with
sanitary landfill disposal as the most economical means of meeting the
areas long-term needs. Since then, three transfer stations have been
constructed as required by the utilization of new landfill sites. The
transfer stations are operated by the Orange County Road Department.
All of the transfer stations in Orange County employ an open-air
direct dump and backhoe transfer system (Figure 12). The waste is dumped
directly into the open-top trailers via hoppers located one level above. .
A mobile backhoe moves from hopper to hopper to compact and distribute
the loads as needed. The large backhoe allows a considerable amount of
compaction to be obtained and payloads are easily achieved. Only munic-
ipal and commercial collection trucks are allowed to use the facility
and no user fees are levied. The double trailer units have a capacity
of 130-cu-yd and have averaged hauling 20.6 tons per load. The total
empty rig weight is 34,200 Ib. A crossed cable arrangement is used to
unload the trailers and the cables must be repositioned manually after
the landfill tractor pulls the load out of the trailer.
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All incoming vehicles are weighed at each transfer station and
accurate records are kept on each operation. Information concerning
each of these stations, extracted from the annual report, of the Orange
County Road Department to the Board of Supervisors, is given below.
Transfer Station No. 1
Stanton
Year constructed 1961 '
Site size 10.8 acres
Hours of operation 7:00 a.m.—4:00 p.riu, Mon-Fri
Number of employees 22
Round trip distance to disposal site 42.5 miles .
Waste transferred (July 1969—June 1970)
Total yearly tonnage 181,195
Average weekly tonnage 3,485
Average daily tonnage 724
Total number of delivery vehicles 30,529 '
Average tons per delivery vehicle 6.0
Total number of transfer trips to
disposal 8,812
Average tons per transfer truck trip 20.6
Equipment Cost each
14 tractors $18,000
19 double trailer sets 18,000
2 backhoes 44,000
2 sweepers 18,000
Initial construction and site development
cost $346,578
Equipment replacement cost at current
prices 699,000 ;
Costs (July 1969—June 1970)
Labor $196,656.92
Equipment 217,578.95
Materials and supplies • 15,073.56
Overhead 82,387.88
Land, buildings, capital projects 18,746.43
Total cost $530,443.74
Total cost per ton $2.93
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Transfer Station No. II
Huntington Beach
Year constructed 1963
Site size 7.4 acres
Hours of operation 7:00 a.m.—4:00 p.m., Mon.-Sat.
Number of employees 19
Round trip distance to disposal site 30.5 miles
Waste transferred (July 1969—June 1970)
Total yearly tonnage 136,022
Average weekly tonnage 2,616
Average daily tonnage 449
Total number of delivery vehicles 27,282
Average tons per delivery vehicle 5.0
Total number of transfer trips to
disposal 6,411
Average tons per transfer truck trip 21.2
Equipment Cost each
9 tractors $18,000
12 double trailer sets 18,000
1 backhoe 44,000
1 sweeper 18,000
Initial construction and site development
cost $212,034
Equipment replacement cost at current
prices 481,420
Costs (July 1969—June 1970)
Labor $160,950.30
Equipment 137,512.16
Material and supplies 13,478.40
Overhead 66,436.15
Land, buildings, capital projects 17,202.59
Total cost $395,579.60
Total cost per ton $2.91
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Transfer Station No. Ill
Anaheim
Year constructed 1966
Site size 7.5 acres
Hours of operation 7:00 a.m.—4:00 p.m., Mon.—Sat.
Number of employees 23
Round trip distance to disposal site 36.3 miles
Waste transferred (July 1969—June 1970)
Total yearly tonnage 206,996
Average weekly tonnage 3,981
Average daily tonnage 741
Total number of delivery vehicles 32,031
Average tons per delivery vehicle 6.5
Total number of transfer trips to
disposal 9,824
Average tons per transfer truck trip 21.1
Equipment Cost eacn
14 tractors $18,000
18 double trailer sets $18,000
2 backhoes $44,000
1 sweeper $18,000
Initial construction and site development
cost $350,042
Equipment replacement cost at current
prices 681,420
Costs (July 1969—June 1970)
Labor $215,961.57
Equipment 225,486.29
Material and supplies 3,877.73
Overhead 87,391.32
Land, buildings, capital projects 52,071.70
Total cost $584,788.61
Total cost per ton $2.82
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In addition to the specific information on each station, the follow-
ing vehicle costs were given.
Fuel Depreciation Maintenance
($7niiTe} ($/raile) t$/nrile)
Vehicle with less than
24,000 miles 0.040 0.070 0.110
Vehicles with 180,000
to 270,000 miles 0.042 0.048 0.160
The transfer stations in Orange County are examples of open-air
operations that have worked well because of the dry, warm climate and
the landscaping work that was done to conceal them. The purpose of the
stations is to reduce transportation costs for route-collection vehicles.
As a result operating costs are kept low (for this area of the country)
because lightweight vehicle traffic is prohibited and user-fee systems
are not utilized.
South Gate, California
The Los Angeles County Sanitation Districts have operated the South
Gate transfer station since 1957 and in addition currently operate five
major sanitary landfills. The transfer station is open to all types of
vehicles and a user-fee system is used. Originally a direct-dump and
backhoe compaction system was utilized, but recently the operation has
been remodeled to incorporate a compaction pit system because of the
increase in the amount of incoming uncompacted waste. The following user
fees are levied:
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$ per ton
Solid waste 5.00
Hard-to-handle bulky material 7.00
Minimum charge 2.00
The facility is an open-air installation and consists of a storage
pit where a crawler tractor compacts the incoming solid waste. The pit
is inclined so the tractor can push the waste to the high end and into a
hopper located above an open-top trailer. A stationary backhoe is used
to distribute the loads after they have been placed in the trailer.
Each transfer rig is composed of a tractor and a set of two trailers.
Each trailer has a 60-cu-yd capacity and the entire rig weighs about
32,800 Ib. With California's 76,800 Ib gross legal weight limit, 22 ton
payloads can be carried. The round-trip distance to the disposal site
is 35 miles and requires about 1-1/2 hour including 25 minutes for
unloading. The trailers are unloaded with a crossed cable pull out
system. Although slower than a self-unloading compactor trailer system,
the authority feels the positive assurance that each trailer will be
unloaded promptly, and that the larger payloads the lighter trailers can
legally carry, compensate for the quick automatic unloading system with
its possibility of hydraulic breakdown.
The facility is open from 6:00 a.m. to 5:00 p.m. Monday through
Saturday and all incoming vehicles are weighed. Unloading vehicles simply
back up and dump into the storage pit. The transfer vehicles have drive-
through access to the loading hoppers and can be loaded in five to seven
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minutes. An average of eight employees are used to operate the facility.
Fifteen sets of trailers and four tractors handle all the hauling duties.
Very little cost information was obtained. With the modifications
to convert the compaction pit system, the total cost was roughly $600,000
exclusive of equipment. The approximate equipment costs are as follows:
Tractors $16,000 each
Pairs of stainless steel
trailers 15,000 each
Backhoes 30,000 each
The facility currently has been handling approximately 200 tons per
day. The opening of a district landfill in the area has resulted in a
decline from 300 tons per day handled in 1969. Cost per ton figures
have, of course, increased with the decreased volume. No current figures
were available; from previous years, however, the cost of operating the
station itself ranges from $1.25 to $1.50 per ton and the haul cost is
approximately $16.00 per hour per transfer vehicle.
The Sanitation Districts have long-range plans for constructing
many more transfer stations as new landfill sites are acquired and the
economy of transfer is justified. Any new transfer operations will be
housed in an aesthetically designed building and will probably utilize
the compaction pit transfer system.
Santa Monica, California
In 1961, Santa. Monica, California started the first stationary
compactor transfer system in the United States. The single compactor
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open-air system is open to all types of vehicles except commercial con-
tract haulers. A user fee of $4.00 per ton is being charged. The
station is open Monday through Saturday from 8:00 a.m. to 3:30 p.m.
Waste from incoming vehicles is unloaded on the ground near the
compactor hopper. A front-end loader is used to charge the waste into
the hopper, and an automatically cycling compactor then pushes the waste
into the rear of an 84-cu-yd enclosed trailer. The trailer is backed
down a ramp and attached to the compactor located at ground level. This
older system utilizes chains to fasten the trailer to the compactor
Instead of the automatic latch used on newer systems.
The round-trip distance to the landfill is 21 miles and requires
about one hour to complete. A unique type of bulkhead unloading system
is used. An air-cooled gasoline engine mounted on the trailer is used to
power a hydraulic winch which is attached to the unloading bulkhead with
a cable. A cable runs from the winch, which is located in the front of
the trailer, over a sheave located in the rear of the trailer and back
to bulkhead. As the cable is wound, the bulkhead traverses the length
of the trailer and ejects the load. The unloading bulkhead also serves
as a packing plate during loading by moving from the rear to the front
as the trailer is filled. A resistance to its movement is applied by
regulating a by-pass value on the hydraulic system.
The empty weight of the transfer vehicle is 42,000 Ib; thus with
California have a gross legal weight limit of 76,800 Ib, approximately
17-ton payloads are possible. Overall the payloads have been averaging
16.4 tons. The station is currently handling about 225 tons per day
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with a fleet consisting of three tractors and three trailers. Six
employees including drivers are employed at the facility.
Cost figures for equipment replacement were not available and initial
purchase price has little meaning in that the equipment was obtained 10
years ago. Current transfer station and haul costs are estimated at
about $2.00 per ton.
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APPENDIX F
COMPARISON OF TWO LARGE-VOLUME TRANSFER STATIONS
Typically, it is very difficult to compare two transfer systems
located in different areas of the country solely on a total cost per
ton basis because wage rates, aesthetic requirements and types of
vehicles handled vary. A basic comparison of buildings, equipment, and
labor requirements, however, as related to daily output, is presented
below to provide an idea of what can be expected from two different
large-volume transfer systems: a compaction pit system used in San Fran-
cisco, California and a stationary compaction system used in Detroit,
Michigan. Both facilities were placed in operation in 1970. Information
on the San Francisco operation was gathered during a site survey while
the Detroit data were gathered by a telephone conversation with the
dperating authority..
This comparison shows the higher output potential of the compaction
pit system and also the greater capacity for handling incoming vehicles.
The stationary compactor system, however, utilizes a very fast and effi-
cient unloading system that does not require additional expenditures
for auxiliary landfill unloading equipment. Two transfer vehicles load
simultaneously in the San Francisco system in a drive-through operation
while five vehicles load simultaneously at Detroit and are required to
back into position. The sixth compactor is used for a spare in Detroit.
Detroit officials stated that they selected the stationary compactor
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COMPARISON DATA ON TWO LARGE-VOLUME TRANSFER STATIONS
Item
San Francisco
Detroit
Type of transfer system
Current one shift handling
capacity (tons/day)
Number of vehicles that
can unload simultaneously
Number of employees
At transfer station
Drivers
Compaction pit
2,000
17
7
16
Stationary compactor
1,250
11
20
San Francisco
Equipment
Detroit
Items Cost each
17 truck and
trailer rigs
2 stationary
backhoes
1 crawler compaction
tractor
2 landfill transfer
vehicle unloaders
$43,000
21,000
65,000
72,000
Items Cost each
32 trailers
16 tractors
6 stationary compac-
tors and hoppers
$18,000
.16,500
22,000
Total Costs
Item
San Francisco
Detroit
Buildings, scales and
site development
Total equipment cost
$895,000
982,000
$863,420
972,000
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system not necessarily as the cheapest method, but as the most sanitary.
The high output at San Francisco, however, requires rapid processing,
*
and therefore exposure of solid waste in the pit is minimal, and the
operation presents little health hazard.
Michigan allows a large legal .gross vehicle weight; thus the seven-
axle transfer vehicles can transport 23 ton payloads. Because of the
lightweight aluminum vehicles used in San Francisco, 25.5 ton payloads
are legally carried even though smaller gross vehicles weights apply.
Overall, the San Francisco operation is faster* eliminates queuing
problems because of,the large storage volumes available and is less
likely to be interrupted by hydraulic equipment breakdown. The Detroit
operation has its advantages in the sealed nature of the transfer
trailers and in the fast, efficient trailer unloading method.
ycr 72145s
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THE FOLLOWING PAGES ARE DUPLICATES OF
ILLUSTRATIONS APPEARING ELSEWHERE IN THIS
REPORT. THEY HAVE BEEN REPRODUCED BY
A DIFFERENT METHOD SO AS TO FURNISH THE
BEST POSSIBLE DETAIL TO THE USER.
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