Discusses the amount of solid wastes generated by wholesale food distribution centers, methods and cost of existing waste disposal systems and recommendations for improvements.Environmental Economics and Policy,

Stearns, Robert P.

English

Research Papers in Economics

Solid Waste Management in
Wholesale Food Distribution Centers
Z%esentecl by ROBERT P. Stearns
Discusses the amount of solid wastes genevated
by wholesale food distribution centers, methods
and cost of existing waste disposal systems and
recommendations for improvements.
ROBERT P. STEARNS is vice president of SCS Engineers.
Mr. Stearns is a registered professional engineer in the
State of California. He was employed as a sanita~y engi-
neer for the Bureau of Sanitation City of Los Angeles
fo~ 7 years. He joined Ralph Stone & Co., Inc., in 1967 as
pvoject manager and was elected a member of the
Board of Directors. Mr. Steams and two other engineers
founded SCS Engineers in 1970. He has directed a number
of projects dealing with solid waste management.
Wholesale food distribution centers help provide for
economical and orderly distribution of farm products to
the consumer. Their location in urbanized areas, however,
has brought their waste disposal practices under the close
scrutiny of local regulatory agencies, Recent concern
with the environment in nearly every area of the country
is limiting the choice of disposal methods while forcing
some centers to improve their existing waste disposal
system,
Six food distribution centers were selected by the
U.S. Department of Agriculture-Marketing Facilities and
Development Branch for intensive study by our firm.
The purpose of the study was to gather information on
solid wastes generated; to determine the cost-effective-
ness of disposal methods in use; and to record descriptive
information on center operations and problems associated
with present disposal methods, Based on this information,
recommendations for applicable waste disposal methods
were to be formulated.
A report describing the results of the study and in-
cluding recommendations was submitted to the U.S. De-
partment of Agriculture in June of 1971. The report
can assist center management in selecting a cost-effective
solid waste management system and provides base-line
information on quantities and types of solid waste pro-
duced in these establishments. The latter information
can aid local public works officials and solid waste COL
lection contractors in assessing their respective roles in
center waste management.
Description and Comparison of
Food Distribution Centers
Descriptive information for the six centers is con-
tained in Table 1, Of the six centers visited by the
project team, four were privately owned, one state owned,
and one municipally owned. The centers ranged in size
from 22 to 146 acres including buildings, paved areas
and railroad track sidings, Tenant stalls at all centers
were approximately the same size (2,500 sq ft ); there
were as many as 254 stalls at the largest center. Tenants
often operated from several stalls depending on volume
and type of commodity distributed.
Fresh fruits and vegetables were the predominant food
commodity distributed. For purposes of the survey, food
quantities distributed were measured by weight (tons)
rather than the more common carlot equivalent used by
the food industry, Although the weight per unit volume
of various foods will vary widely, field data indicated
Table 1. Descriptive Information on Food Distribution Centers Surveyed
Area
per
sta II
Total Number
Location
Including Number
Year
Center (state)
area of platforms of
opened Ownership (acres) stalls (Sq ft) tenants
1 Texas 1951 Private 36 84 2,250 34
2 California 1962 Private 16 84 2,200 15
3 New York 1967 Municipal 116 252 2,500 110
4 Massachusetts 1968 Private 37 130 2,400 51
5 Kentucky 1955 Private 22 50 2,750 14
6 Georgia 1959 State 146 254 2,250 51
JULY 72/page 62 JOURNAL OF FOOD DISTRIBUTION RESEARCHthat on the average, 19 tons of food was contained in
each carlot equivalent, Food quantities received in the
year 1970 at the six centers varied from 95,000 tons at
the smallest center to over 1,170,000 tons at the largest
center,
Common solid wastes included culled or spoiled prod-
uce, food trimmings, paper, cardboard, wood, and other
packing material. The quantity of solid waste generated
per ton of food distributed averaged 20 lbs or 1 percent
by weight and ranged from a low of 14 lbs at one center
to a high of 36 lbs at another center.
,/:
.0 /’”
.’- CENTER DES! GNATlON NuMBER
*kLl” #
IO, 200 300 400 500 6., 700 no, ~OQ IOoo ]100 ’200
%
FOOD QLIANTITY c>ISTRI BUTED (1000 TONWEARI .
Figure 1 graphically depicts the relationship between
the quantity of food distributed and the total quantity
of solid waste produced as determined from the surveys.
Table 2 identifies waste types and provides represent-
ative density figures for the wastes found at the centers.
Table 2. Solid Waste Characteristics
Range in
Average density
average density
Waste type in ioose condition
(lbs/cu yd)
and category (lbs/cu yd) High Low
Food
Spoiled 685 950 400
Scraps 685 950 400
Non-food
Corrugated 75 200 50
wood 200 350 150
Paoer 150 200 100
Present Waste Management Metlaods and
Associated Problems
Several methods were used to dispose of solid wastes
from the centers surveyed. Methods used resulted pri-
marily from the type of ownership, the importance of
sanitation to the manager, and local regulations governing
waste handling and disposal. The age and physical con-
dition of the grounds and buildings and the degree of
cooperation afforded to managers by tenants were also
factors.
At the cleaner centers, the conditions reflected tenant
acceptance of the need for proper waste containerization
and regular collection service. The manager also ex-
pressed concern for sanitation and enforced rules gov-
erning waste management at these centers.
At all centers surveyed, the tenants had responsibility
for maintaining their own stalls in a clean and sanitary
fashion. In nearly every case, the stalls were adequately
cleaned on a daily basis. However, conditions outside
the tenant stalls reflected less concern and as a result
were often heavily littered with wood, cardboard, paper
and rotting produce.
Crowded conditions in truck loading and unloading
areas often made waste collection operations difficult.
At one center, tenants were permitted to sweep stall
wastes off the loading docks onto the ground, Spoiled
and culled produce at this center were placed in card-
board boxes by the tenants for pickup by local hog
farmers. However, significant amounts of these highly
putrescible materials also were found on the ground,
Waste storage containers were used at the remaining
centers and some form of routine collection service pro-
provided by either the local municipal collection agency,
a private contractor, or center personnel. A combination
of service was frequently provided, with the private
contractor, municipal collection agency, and center per-
sonnel each responsible for some aspect of waste disposal.
For example, at one center a private contractor collected
wastes from tenants while municipal crews cleaned the
paved areas of the center. Center personnel were re-
sponsible for cleaning the railroad track areas. Even at
those centers receiving regular collection service, a con-
siderable quantity of waste material accumulated daily
in the truck and railway car unloading areas.
Problems with waste disposal were due to several
reasons, Primary among these were the lack of proper
waste storage containers and infrequent collection serv-
ice. This resulted in overflowing containers and waste
spillage onto loading docks and paved areas. Wind and
trafEc often carried the waste to other locations on the
center property.
Disinterest and/or inactivity of both managers and
tenants was another factor contributing to litter. The
lack of clear-cut lines of responsibility for solid waste
management was a problem at most centers.
Waste accumulated in the house and team track areas.
These areas were difficult to clean because of parked
rail cars or poor or non-existent paving. In most cases
shipping and packing wastes in the railroad car were
swept out of the car onto the ground.
Cleaning of streets and other areas was the responsi-
bility of either the center or the local municipality,
Equipment used for cleaning included mechanical street
sweepers, skip loaders, dump trucks, and hand tools.
Larger waste items, such as cardboard boxes, wood pallets,
and other similar material could not be picked up by
conventional means and costly hand labor was often
required,
Final disposal point for most of the waste was the
landfill, At bne c&ter, a small incinerator was operated
for disposal of cardboard cartons. A larger modern in-
cinerator had been abandoned as uneconomical at an-
other center. Existing incinerators at other centers had
been closed by local air pollution control agencies,
Grinding food wastes for disposal to the sewer was
used by some tenants processing or packing produce.
For occasional large quantities of unsalable produce,
centers disposed of the material at landfill or distributed
it to charitable organizations.
Costs of existing waste management, inchlding col-
lection, disposal and administration, varied from $7 to
$41 per ton of solid waste removed with the average
for the six centers being $25 per ton of waste.
Development of A Waste Management System
The basic components of a waste management system
include the storage container, collection procedure, waste
JOURNAL OF FOOD DISTRIBUTION RESEARCH JULY 72/page 63transport to the disposal site, and final disposal, Street
and paved area cleaning is also a part of the system.
Final disposal may be an incinerator, landfill, or other
method.
Waste Storage Containers. Containers are needed to
properly store waste until collection and should be located
near the point of waste generation, i.e., the individual
tenant’s stall, center restaurant, or administrative office,
Container needs are based on the volume of waste
generated, the collection frequency, and the type of
collection method used, Each tenant should have ade-
quate storage capacity for wastes generated between
days of collection,
Quantities and types of solid waste material generated
by tenants will vary, During the field survey, the weekly
volume of waste ranged from less than 1 to over 4 cu yds
per stall. Because of this variation, a survey of quantities
generated by each tenant is necessary to determine con-
tainer needs. Container types and sizes should be uni-
form in the center, This facilitates collection in an efficient
manner,
Due to the organic nature of some center wastes, and
the waste volumes generated, containers should be emp-
tied at least twice each week. Containers recommended
for use by tenants include salvaged 55 gallon drums or
metal bins, with the latter preferred. Metal bins are
available in capacities of from % to 8 cu yds and range
in cost from $90 to $700 each.
For storage of solid waste from several tenants, a
larger container or use of a stationary compactor is
recommended.
The stationary compactor is designed for use when
large volumes of solid waste are produced, When cen-
trally located at the center, preferably immediately ad-
jacent to a loading dock, it is available for use by
tenants whenever needed,
The compactor consists of a charge box and hopper
opening into which waste is deposited. A hydraulically
operated ram pushes the waste through an opening into
an attached container, The waste is compressed and
completely enclosed in the compaction container thereby
reducing waste volume by one-third or more and mini-
mizing fly and odor problems. The enclosed container
prevents scavenging of discarded produce by unauthor-
ized persons, When the container is full, it is detached
from the compactor and hauled to the disposal site,
The stationary compactor can accept all types of
waste generated at a center, including wood pallets.
In most localities stationary compactors may be leased
from distributors or from private collection contractors,
Installation costs, not including the compactor, average
about $3000, For a five-year lease, compactors generally
cost from $500/yr for a 35 cu yd per hr size to $1250/yr
for a 100 cu yd per hr model, Periodic dumping of the
container is not included in this costs.
Collection and Transportation The volume of waste
produced by the tenants, the number of containers to be
serviced daily, and the transport distance in large part
determine the requirements for collection vehicles, In
general, as haul distances increase, so should the capacity
of the collection vehicle.
Figure I is useful in determining anticipated total volume
of solid waste, based on quantity of food distributed. Con-
version of weights to cu yds can be made using average
density values presented in Table 2. However, verification
of derived values for a particular center is recommended.
Small 3-wheeled collection vehicles can be used to
transport wastes from tenant containers to a stationary
compactor, or to a center incinerator, These units have
capacities ranging from 1-3 cu yds and cost from $2500-
$7000 each, Tenant storage containers should be 55 gal
drums when this method of collection is used.
Larger compaction trucks capable of collecting and
transporting wastes from many tenants to a distant dis-
posal site are available in capacities up to 40 cu yds.
They range in cost from $8,500 to $40,000, These units
are “comm-only used by private collection contractors and
municipal agencies engaged in waste disposal service.
Some are equipped with devices for mechanically loading
large waste storage bins.
Alternative Disposal Methods. There are several meth-
ods of disposal suitable for wastes originating from a
food distribution center. An incinerator may be economi-
cal for disposing of wood pallets, cardboard cartons,
waste paper, and other combustible wastes if landfills
are located at long-haul distances from the center. How-
ever, center food wastes are difficult to burn and in-
cineration of th,is material is impractical unless the com-
bustible materials can be properly mixed with the food
waste prior to incineration. Problems in meeting local
air quality regulations may arise. Since incinerators have
high purchase and operating costs, careful economic an-
alysis should precede any proposed installation.
All center wastes can be readily disposed by the
sanitary landfill method. This method involves com-
pacting and covering the waste with earth to preclude
environmental nuisances. Sanitary landfill is less expensive
than incineration provided a landfill site is available
within a reasonable haul distance of the center.
Garbage grinders can be used by those tenants pro-
cessing food. The grinder can be placed in the process
line to grind material directly to the sanitary sewer.
Larger grinders operated by the center for tenant use
may be feasible. Grinding of food wastes to the sanitary
sevjer is prohibited in sore; locations.
Food type wastes can be fed to hogs. Restrictions by
local health authorities may effectively preclude the use
of this method, however. The seasonal ‘variation in hog
feed requirements may not coincide with the center-
generation of food type wastes and separation of food
waste from non-edible waste would be required. Con-
trol of collection is difficult.
Salvage of wood pallets and cardboard may be poss-
ible depending on local market conditions for these items.
Recommended Waste Management System
The manager of the center should have responsibility
for waste management, As a part of this responsibility,
he should be authorized to administrate all waste col-
lection and disposal services provided tenants, to con-
tract with private firms for services, or to establish center
capability ~n terms of labor and equipment to provide
for waste disposal as required.
Each tenant of the center should be provided with
and be required to use the proper number and type of
waste storage containers based on the volume of waste
generated. Tenant containers should be uniform in size
and design throughout the center and be serviced a
minimum of twice each week, Tenants generating larger
volumes of waste would use additional containers or
have their containers serviced more frequently. Waste
storage containers should be located as near the point of
waste generation as is practical. The rear dock area is con-
venient for tenant use and for collection service acces-
sibility.
Co~lection of waste from elevated and street level rear
dock areas can be made using a front-end loading packer
vehicle. Waste containers used when collections are made
from the dock should be of the metal bin type equipped
with casters and lift handles to facilitate use by tenants and
mechanical loading.
JULY 72/page 64 JOURNAL OF FOOD DISTRIBUTION RESEARCHBecause of high costs and increasingly stringent air
pollution control regulations, the installation of an incinera-
tor for disposal of center wastes is not recommended, Near-
by municipal or privately operated sanitary landfill sites
can provide economical disposal for center wastes, Several
storage containers of 4 to 6 cu yd capacity should be lo-
cated on the center premises and truckers encouraged to
dispose of packing wastes into these containers, These
containers can be used for railway car packing wastes also.
Hog feeding of center food wastes should not be con-
sidered a reliable, longterm waste disposal method. If
hog feeding is considered, local regulatory agencies having
jurisdiction over feeding of garbage to animals should be
consulted. In addition, center management must establist
rules under which the hog farmer will operate to insure
uninterrupted food waste removal in a sanitary manner,
Tenants processing or preparing produce for packaging
and center restaurants should be encourage or required,
local regulations permitting, to install a garbage for dispo-
sal of food wastes directly to the sewer sysem. Installation
of these units during new center construction is strongly
recommended.
The streets and other paved areas of the center should be
swept at least twice weekly using a mechanical street
sweeper. To facilitate this cleaning activity, all trucks
and piggy-back trailers should be parked away from the
dock on designated days (during night sweeping hours).
A skip-loader or hand labor can be used to remove items
too large for pick-up by the sweeper. Unpaved railroad
track areas should be paved to facilitate the used of ef-
ficient mechanical street cleaning methods.
When a suitable location exists at the center, the in-
stallation of a stationary compactor should be considered
by market management, Use of a pickup truck or small
three-wheeled collection vehicle can be used for trans-
porting tenant wastes to the compactor if the compactor
cannot be located readily accessible to the tenants, In gen-
eral, only the largest centers (receiving at least 1,000 tons
of produce daily) should consider the purchase of equip-
ment and the hiring of labor to provide waste disposal
service for tenants, Others, particularly those privately
owned, should contract with a competent private hauler for
the required service. Municipally owned centers may have
access to municipal waste collection service. If the center
wishes to evaluate establishing its own waste disposal
operation, or the installation of a stationary compactor a
careful planning and evaluation period is recommended.
An engineer experienced in solid waste management should
be retained to evaluate center conditions and recommend
eqllipment and other system components. Service cost
estimates submitted by local qualified private haulers
should be included in the evaluation process. Specifications
governing the services to be provided by the private hauler
are recommended. Competent technical and legal advise is
needed to prepare the specification.
ACKNOWLEDGEMENT
This work upon which this publication was based was per-
formed persuant to Contract No. 12-14-100-10322 (52)
with the U.S. Department of Agriculture.
JOURNAL OF FOOD DISTRIBUTION RESEARCH

SOLID WASTE MANAGEMENT IN WHOLESALE FOOD DISTRIBUTION CENTERS

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