S17-575
RESOURCE
R ECOVERY
TeCH-hOLOGY
UPDhTG
FRO/Vl THE USEPk
STEPHEN A LINGLE, CHIEF
Office of Solid Waste Management Programs Technology & Markets Branch
RESOURCE RECOVERY THROUGH
MULTI-MATERIAL SOURCE SEPARATION
By Penelope M. Hansen
Municipal waste recycling by citizens through vari-
ous forms of source separation has been an integral
part of the environmental movement from its inception
in the 1960's. Since that time, thousands of recycling
centers and hundreds of curbside collection programs
have come into being. All have had as primary mo-
tives the conservation of resources and reduction of
solid waste requiring disposal.
The majority of recycling centers have averaged a
one percent reduction in community waste going to
disposal, although outstanding exceptions exist—such
as Berkley, which recycles almost 15 percent of its
waste stream through recycling centers. Curbside
separate collection programs in general have had
considerably greater effect, recycling from 4 percent
to 9 percent of community waste, but these programs
have been limited almost exclusively to newsprint
and, occasionally, mixed paper collection. While
clearly more effective than collection centers, curbside
recycling programs nonetheless have suffered from a
limitation in scope.
Obviously the factor of convenience has played a
major role in encouraging more people to participate
in curbside programs than in recycling center pro-
grams. Based on the premise that minimizing house-
holder inconvenience would maximize the materials
recovery potential of a source separation program, the
Environmental Protection Agency (EPA) is demon-
strating the effectiveness of large scale materials re-
covery in a community-wide weekly multi-material
curbside collection program. Two Massachusetts
communities, Marblehead (suburban) and Somerville
(urban), received EPA grants in 1975 to demonstrate
such programs. The collection systems were de-
signed to recover a wide range of materials (all flat
paper, cans and glass) from the waste stream.
Preliminary results from the first seven months of
operation have been encouraging. Marblehead has
recovered from 23 to 33 percent of its residential solid
waste stream each month since the program began in
January, 1976. Somerville has recycled from 7 to 10
percent of its waste stream.
Marblehead: The Suburban Prototype
Marblehead is an affluent suburban community of
23,000 people located north of Boston. In 1972, long
before EPA's involvement, this community passed an
ordinance mandating separation of recyclable materi-
als. The system required separate monthly collection
of paper, cans, clear glass and green glass. Each ma-
terial was collected once per month on a rotating
weekly basis. Therefore, there were four separate ma-
terials which required storage space at the household
for a month. Although this program was not optimum
from a householder convenience standpoint, its exis-
tence, and the publicity it received, greatly influenced
community interest and participation in the EPA dem-
onstration program which began in January of this
year.
The demonstration program was designed for
greater simplicity and less householder inconve-
nience. It provides only three levels of separation:
1. all flat paper
2. clear glass and cans
3. brown and green glass and cans
All recyclable materials are collected weekly in a
compartmentalized vehicle. The compartmentalized
truck has three compartments, separated by parti-
tions, which extend lengthwise in the truck body. The
size of each compartment is based on the quantity of
each of the three categories typically collected. The
materials are first placed in compartments in a hydrau-
lically operated rear lift on the truck. When these small
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compartments are filled (every few homes) the lift is
raised and emptied through the top of the truck. The
collection truck was designed and constructed by the
Rendispos Corporation* of LaRose, Illinois, has a 16-
cubic-yard capacity and holds 21/2-3 tons of material.
Because the vehicle does not compact its cost of ap-
proximately $20,000 is considerably below that of a
standard packer.
The combined glass and cans are separated me-
chanically by a processor who purchases the materi-
als prior to sale to an ultimate user. Since other mate-
rials are not mixed with the glass and cans, it is pos-
sible to separate glass, steel cans, and aluminum
cans from each other with relatively simple screening
and magnetic separation. The paper is processed by
a wastepaper dealer for use by a paper mill.
Table 2
MARBLEHEAD PROGARM ECONOMICS
($ per month)
Revenues
from
Sales
January 112-31)
February
March
April
May
June
July
1870
2560
3790
3500
3400
3730
3280
Diverted
Disposal
Savings
2990
3390
3680
3640
3390
3850
3350
Incremental
Collection
Costs
2930
3570
4450
4470
3S50
4240
4040
Net
Savings
1930
2380
3020
2670
2940
3340
2590
*Includes labor costs as well as operation, maintenance and
capital amortization for the compartmentalized trucks and all other
equipment added as a result of the source separation program.
Recovery Levels
The amount of materials recovered has remained
more or less constant since the beginning of the pro-
gram, averaging roughly 200 tons per month.
Throughout the program approximately half of the re-
covered tonnage has been paper, while the remainder
has been mixed glass and cans (Table 1.) Though
specific surveys have not been conducted, it is esti-
mated that at least 75 to 80 percent of the house-
holders participate in the program.
The remaining waste stream in Marblehead has
gone through dramatic fluctuations, increasing from
379 tons in February, 1976 to a high of 689 tons in
June, 1976 (Table 1.) This increase is assumed to be
the result of lawn clippings and general spring house-
cleaning. In July, both the non-recycled portion and the
recycled portion dropped, probably as a result of family
vacations.
'Mention of product does not indicate endorsement
Total Residential
Recovered Materials
% of
Cans and Residential
Month
January (12- 31)
February
March
April
May
June
July
August
_Wast£
475
560
690
720
795
890
755
880
Pji£er.
80
80
90
90
95
105
85
105
_Glass
75
95
100
100
85
100
100
95
Total Jla:
155 3:
175 3;
190 2(
190 2}
130 2:
2C5 2:
135 2:
209 2:
*Though amounts recovered have increased soieuhat since the program began,
dramatic increases in the total waste strewn during sunder months have resulted
in a declined in the recycled percentage
Public Awareness Campaign
The public education efforts which brought about
the high participation rate in Marblehead were well
planned and extensive. A full report on all steps taken
to motivate the community to recycle will be published
by EPA by the end of this year. Extensive use of local
newspaper, radio, and Boston TV stations, was made
as well as community service groups, public schools
and local merchants. Heavy emphasis was placed on
the economic benefits of recycling, as well as the en-
vironmental benefits. The publicity campaign cost for
the first year was $4000, which included a nominal
sum for the salaries of the two coordinators.
Economics
The cost figures show the town to be making a prof-
it. Table 2, in simplified form, depicts Marblehead's
program economics. All figures presented are calcu-
lated on a full-cost basis, excluding the EPA grant.
Availability of good local markets for all of the mate-
rials separated has had a major influence on the
economic success of the program. Revenues from the
sale of materials over the seven-and-a-half-month
program have ranged as follows:
Paper—$12 to $27 per ton
Glass—$12 per ton
Cans—-$10 to $29 per ton
In each case the sale of materials is secured by a
one year contract that guarantees a minimum base
price of $5 per ton for paper, $12 per ton for glass and
$10 per ton for cans. As the market price rises above
these minimums, the price received by the town rises.
Since the mixed glass and can fraction must be me-
chanically separated by the purchaser, the revenue
received by the town is lower than it would be if the
materials were separated when purchased. However,
it is felt that eliminating the separation of cans and
glass, (and reducing householder effort,) significantly
adds to the volume of materials recovered to the point
where the lower revenue received per ton is more
than justified by increased volume.
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The second column of Table 2 indicates
Marblehead's most compelling economic reason for
instituting the recycling program. Marblehead cur-
rently pays a private hauler $18.95 per ton to dispose
of municipal solid waste. By recycling about 200 tons
of residential waste each month the town has saved
nearly $3800 (per month) in disposal costs, in addition
to receiving revenues for the sale of the material.
Incremental costs (Column 3 of Table 2) are the
additional costs which the town experiences due to
the recycling program over and above expenditures
normally budgeted for solid waste management. As of
this writing the regular waste collection system has
not been optimized to take advantage of the approxi-
mately 25 percent reduction in mixed waste collected.
Optimization steps currently under consideration
could lower collection costs by as much as $80,000
annually. EPA's Office of Solid Waste Management is
providing technical assistance to the city to aid them
in evaluating these optimization efforts.
Somerville: The Urban Prototype
Somerville is a densely populated urban community
where 90,000 people inhabit four square-miles. The
population density of 27,000 people per square-mile is
one of the highest in the nation. In contrast to
Marblehead, the city has had no previous recycling
experience prior to the EPA funded program. This
may have influenced the relatively low recovery rate
of 7-10 percent (compared to Marblehead's 23-33
percent recovery rate.)
The recyclable collection system employed in
Somerville began in December, 1975. It is similar to
that used in Marblehead with one major exception:
the Somerville program involves only two levels of
separation; 1) all paper, and 2) all cans and glass
(mixed.) Since cans and both clear and colored glass
are mixed together in a single container, only two
compartments are needed in the collection vehicle,
rather than three as in Marblehead. As in Marblehead,
the cans and glass are separated mechanically by a
processor who purchases the materials. The mixing ol
both clear and colored glass is feasible in Somerville
because the processor has a sales contract for mixed
color glass. The paper is processed by a wastepaper
dealer for use by a paper mill.
Recovery Levels
Table 3 depicts tonnages of waste disposed of
and recovered over the course of the Somerville
program. The figures for December, January and July
are distorted by collection-crew strikes and severe
snow storms which caused the program to be sus-
pended for two weeks during each of these months. In
each case these breaks in program continuity have
had a detrimental effect on the citizen participation
rate and on program economics.
Economics
Table 4 presents data on program economics frorr
December, 1975 to July, 1976. Net costs were in-
curred in four of the months shown, and a small profit
was realized in the other four. At Somerville's present
recycling rate it is hoped that the program will break
even for the year.
Somerville's materials sales contracts are the same
as Marblehead's with one exception: because
Somerville is located approximately an hour's drive
away from the purchaser, the collected materials are
loaded into 40 cubic-yard bulk containers at the city's
transfer station. These containers are hauled away
twice a week by the purchaser. This transportation
factor has lowered the revenue received by the city to
the ranges shown below:
Paper: $6-$21 per ton
Glass: $10 per ton
Cans: $5-$27 per ton
Somerville's disposal cost of $14.75 per ton paid to
a contractor is a major factor in the economic viability
QUANTITY OF MATERIALS RECOVERED
IN SOIIERVIILE
(tons)
Total Residential
Waste
1850
1120
2430
2890
3105
3260
3340
1295
2975
Pap_er
130
60
120
145
145
150
160
50
135
Recovered Materials
Cans and
Glass _
50
40
75
75
80
90
130
50
110
% of
Residential
Total __ Waste **
100
195
220
225
240
290
100
240
10
9
Table 1
SOMERVILLE PROGRAM ECONOMICS
($ per month)
December (1-14)*
January (12-31)*
February
March
April
May
June
July*
Revenues
from
1240
720
2080
3890
3350
3600
4200
1460
Diverted
Disposal
Savings
2670
1460
2890
3260
3350
3530
4290
1480
Incremental
Collection
Costs
7280
3570
5290
6930
6500
6200
6790
2950
Net
Savings
(Costs)
(3270)
(1390)
(320)
220
200
930
1700
(10)
**Though amounts recovered have increased somewhat since the program began,
dramatic increases in the total waste stream during summer months have resulted
in the recycled percentage remaining nearly constant.
*Stn"kes and snow storms prevented recyclables collection for
two weeks In each of these months.
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of its program. As in Marblehead, each ton recovered
lowers disposal costs significantly.
A major problem impacting on the economic effec-
tiveness of the program is the relatively low participa-
tion rate. If more people participate in the program, it
clearly will be standing on much firmer economic
ground.
Conclusion
The Marblehead program is yielding encouraging
results with high participation and cost savings to the
city. The primary goal of the second year of the
Marblehead recycling program will be the optimization
of collection practices to bring costs to a minimum and
take full advantage of a reduced waste stream. Con-
sidering the skepticism often associated with separate
collection in densely populated urban areas, the
Somerville program is off to a credible start. The
major effort in Sommerville will be to motivate a larger
segment of the population to separate their wastes for
recycling, and thus improve waste diversion and pro-
gram economics. EPA will present further reports as
these two programs progress. •
REPRINTED FROM WASTE AGE, OCTOBER 1976
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