EPA/600/A-94/210
94-RP140.03
Landfill Reclamation - Potential for Recycling/
Reuse and Results of the Evaluation of the
Collier County, Florida MITE Demonstration
Lynnann Hitchens
U.S. Environmental Protection Agency
Cincinnati, Ohio
Air & Waste Management
ASSOCIATION
~
Since 1907
For Presentation at the
87th Annual Meeting & Exhibition
Cincinnati,Ohio
June 19-24,1994
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94-RPK0.03
INTRODUCTION
In October 1993, Ibc US Environmental Protection Agency (EPA! issued the report "Evaluation
of the Collier County Florida Landfill Mining Demonstration " This technology was developed
by the Collier County Solid Waste Department and was evaluated as a part of EPA's Municipal
Solid Waste Innovative Technology Evaluation (MITE) Program The purpose of the MITE
program is to objectively evaluate innovative solid waste management technologies and transfer
the resulting information to municipalities and solid waste managers.
This paper details the demonstration and the subsequent evaluation of the landfill mining, or as
it is often called, landfill reclamation technology. Included among the results of the numerous
tests conducted during the evaluation period is a waste characterization that was performed on
all separated streams and physical and chemical analyses of the toil fraction for comparison to
Florida State Compost Regulations. The other aepamted fractions (ferrous and plastic) were
evaluated for their recycling market potential During one week of the demonstration, air
quality measurements were liken for a full range of contaminants After testing was
completed, die data were used to estimate the capital and operating costs of the system, and the
processing cost per ton.
EXPERIMENTAL METHOD
Tke MITE Program
The US EPA established the Municipal Solid Waste Innovative Technology Evaluation (MITE)
Program to provide municipalities and the public lector with information on new and
developing solid wacte management technologies. The MITE program provides a framework
within which technology developers have the opportunity to demonstrate the effectiveness of
their technology or process in the field. Technology proposals are solicited once per year and
are reviewed and selected by an Advisory Committee made up of local and State solid waste
recycling coordinators. This ensures that public sector needs are given consideration when
choosing evaluation technologies. The Advisory Committee, as welt as the subsequent
evaluations, are administered for EPA by the Solid Waste Association of North America
(SWANA).
After selection the demonstration is planned according to the needs of the technology
developer. EPA tries to tailor the evaluation id meet the technological and research needs of
the developer, as well as meet the information need of local government and the public sector -
- the potential purchasers or iMets/apemois of the waste management technologies. Each
project is conducted jointly; the technolofy developer is responsible for funding and directing
the demoastiation of the technology and EPA funds and directs the technical and economic
evaluation.
At the completion of each evaluation, a report that contains the results of the technical and
economic assessment is published. The rcpoit serves as a marketing tool for the private
developer and is widely distributed by EPA in response to requests for information and for the
purposes of technology transfer. The MITE program has completed five evaluations to date,
and las six ongoing projects.
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•M-KI'HO.M
l andfill reclamation w;is submitted to the MI TI¦ program by lite Collier County Solid Waste
Department, and was selected in May 1
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94-KPU0.O}
material (less lhan six inches) is conveyed to the trommel. The purpose (if I he trommel is to
separate the soil fraction (SI) from the remaining material. The trommel has .3/4 inch
openings through which (he soil and degraded material pass. "1'his material is usable as cover on
the active part of the landfill, and represents a significant percentage (nearly Ml '/r) of what is
being processed.' A significant amount of sampling and analytical testing was performed on this
material. The majority of the tests were for comparison to Florida State compost regulations
and also included bacteriological testing, fiber analysis, metals and trace chemical composition.
The oversized material (> 3/4 inch) moves from the trommel, onto a conveyor anil through the
final two unit operations, separating it for possible recycling. A ferrous magnet is used to
separate the ferrous material (S3), and the remainder of the material enters the air knife.
"lite purpose of the air knife is to perform a density separation by blowing, with high speed air,
the lighter, smaller material from the unit, while the denser, heavier and larger material falls to
the bottom and is collected. At the entrance to the air knife all material passes over a vibrating
finger screen with 3/4 inch openings, through which small, heavy material falls. These "finger
screened unders" (S8) are collected for disposal. The oversized material enters the fluidizing
section which was modified to produce three additional process streams. "Hie high speed air
stratifies the material to enhance the removal of smaller size, high density refuse particles. The
large heavy material (S<>) is bottom discharged and the lighter material that is blown through
the air knife was separated into a moderately light fraction (S4/SS) containing mostly
aluminum, glass, some soil and small plastic fragments, and a "super light" fraction (S2) which
essentially contained plastic film.
The original process design also contained an eddy current separator between streams S3 anil
S4/S5. The purpose of the eddy current separator was lo remove the aluminum fraction, but
after a few test runs it was determined that the eddy current separator was incompatible with
the capacity requirements and particle size of the feed stream. At this point in the process line,
the feed stream was a soil-coated heterogenous mis of material that did not permit the
equipment to operate properly. Since this unit was removed, the residue stream (S4/S5)
contained a significant amount of aluminum. With proper equipment, the residue would have
been separated into two separate streams: aluminum (S4) and residue (SS).
Evaluation Objectives and Methodology
The EPA MITE evaluation established a number of objectives with our overall goal being an
assessment of the landfill reclamation .system during the demonstration period. Among them
were to:
• Determine the maximum processing rate for the tested equipment.
• Evaluate the unit operations and their ability to produce process streams of required
purity.
• Determine the composition of the mined material.
» Evaluate the soil fraction in comparison with Florida State compost standards to
determine its applicability as a soil amendment.
• Evaluate the marketability of the product materials such as ferrous, plastic, and
aluminum.
• Determine the cost of operation.
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'i/.-kiMAn.cn
In pinsuim: llioe nhieiliwv .1 mil' \u-ek nine pelmil u.i^ ilewMeil In niiinitoring (lie
system/proeess llou*. .mil nhi.lining lite neeessarv samples "I lie on-site data collection for the
evaluation was divided lulu ihiec parts: mass balance. slreain sampling and waste
characterization, ami air monitoring at Ihe site-
Mass Balance. The mass balance was conducted to ensure that all material was accounted for.
and the waste composition study yielded accurate results. The landfill scale was used for all
materials at the input and output locations. Prior to placing the material on the process line,
mixed, excavated material was loaded into a roll off hox and weighed. At the output of each of
the unit operations, conveyors emptied each of the process streams into separate roll off hoxes.
These were also Hauled to the scale house daily for weighing.
Stream Sampling and Waste Characterization. Each product stream (soil (SI), plastic (S2),
ferrous (S3), and aluminum/residue (S4/S5)) was sampled for characterization, with subsamplcs
being taken for analysis. To obtain product samples, I - 1.5 yd" samples were collected from
the roll off containers and delivered to the sampling area. Hie material was spread evenly over
a grid and a random number chart was used to select the grid square for subsampling. These
subsamplcs were weighed and shipped to the analytical laboratory for chemical analysis. The
remaining material was placed on a sorting table for characterization, using the thirteen
categories as listed below:
Paper and paperboard
Glass
F;errous metal
Non-ferrous metal
Textiles
Plastic
Rubber/leather
Non-proccssible
Inert (soil)
Yard waste
Food waste
Aluminum
Unidentifiable
Air Monitoring. An air quality survey was also performed and conducted concurrently with Ihe
product sampling and characterization. Twelve individual air sampling episodes, three ambient
measurements, four at the grizzly screen and five at the trommel, were conducted over five
days. Both upstream and downstream measurements were taken. Air samples were evaluated
for total and respirable particulate matter (dust) and microbial agents, including total bacteria
and total fungi, a range of metals and fibers.
RESULTS AND DISCUSSION
Mass llalanre
The actual equipment used in this demonstration was provided by vendors for the purposes of
this demonstration. This limited the process train and the ability to match the throughput
capacities of the equipment. Under ideal circumstances and unlimited resources, the vendors
would be included in the planning process and it is likely that processing capacity and
availability could be increased. Availability averaged 53 % , assuming 24 possible hours for the
first week of the field test, and reached a peak of 89 %. During hours of operating 242 tons of
mined material were processed. The average processing rate during the evaluation was 1.3.3
tons per hour (TPU), with a minimum of 10.4 TPII and a maximum of 18.1 TI'II obtained.'
Operation was stopped during the periodic rain showers, common for 1-lorida. and one instance
of equipment failure, which was quickly repaired.
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94-RiM4n.rn
Pic mass balance data were collected during 24 hours of evaluation. A summary of the mass
balance appears in Table I, as weight percentages of each stream as a fraction of the total
amount of material processed (2')2 tons). The criteria for closure of the mass balance was that
the sum of the output streams had to equal or exceed 90% of the input stream over the entire
length of the evaluation. The average output/input was 90.2 % and the criteria was met,
indicating closure of the mass balance.' The product streams can be accurately expressed as a
fraction of the total amount of material processed.
Waste Characterization
Twenty nine samples of the four product streams (SI, S2, S3, S4/S5) were collected and
characterized by the project team (Some streams were sampled and characterized more
frequently, due to the amount of product being produced). Of the 29 samples collected and
sorted, the average sample weight was approximately 54 lb* After each sample was separated
into the 14 categories, each of the 14 subsamples was weighed, so that the composition of each
product stream could be computed. Table 2 lists the composition of each of the four product
streams, according to these fourteen categories. As shown in this Table, each product stream
was not 100% pure, and contained material other than the material targeted for separation.
The soil product stream (SI) was the purest, containing 94.2 % by weight of soil and inert
material The aluminum/residue stream (S4/S5) was the least pure, with respect to any
recoverable component, since it was a mixture of material not isolated by any of the previous
unit operations.
Table 3 presents the same information, coupled with the mass balance data. This Table can be
used to measure the success of each of the unit operations in recovering the maximum amount
of the respective product. Note that the purpose of the trommel, (shown in Figure I as
producing stream SI) was to recover all soil material. Table 3 shows that the trommel
recovered 94.7 % of the total amount of soil excavated with the remaining 5.3 % appearing in
other product streams, S2-S9. The plastic was not as easily recovered by the air knife, with
only 42.1 % of the total amount found in this stream (S2). I"his is a reasonable value, since the
majority of the plastic was film, and it was easily entrained and adhered to other materials,
being removed before entering the air knife, the last unit operation in the process line.
Soil Fraction Analysis
The soil fraction underwent chemical analysis for 16 metals. None of the metals tested that
would be regulated under RCRA would exceed regulatory limits. Table 4 shows the results of
several of the analyses and the Florida State Heavy Metal Criteria for Compost, Concentration
Code 1. Concentration Code I is the most stringent regulatory limit for metals of the four
Heavy Metal Criteria Codes for compost. The soil fraction does not exceed any of these
regulatory limits. For unrestricted use in Florida (Florida Compost Classification Type A), the
material must also contain less than or equal to 2% foreign matter.' The soil fraction contained
synthetic fibers in the range of 1% to 2% and fibrous glass in the range of 2% to 5%. There
was also the visible presence of broken glass. F.ven though the soil fraction meets the most
stringent Heavy Metal Criteria for compost, it would only be Classified as a Type C compost or
lower. The allowable use would be restricted, but still would be suitable for some institutional
operations and at a landfill, as cover soil.
The soil fraction underwent testing at the Federal Seed laboratory in Beltsville, Maryland The
soil fraction did not exhibit any phytotoxicity and in the eight samples tested, the germination
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9'.-RI" I 40. in
throughout the sampling program. Operators who may he more susceptible might wear
disposable dust masks which would minimize exposure (even minor) to microbiological
contaminants and metals ''
While a risk assessment was not performed, the operation did not appear to pose any hazards
that would not normally be present at solid waste landfilling or strip mining operations. This
judgement is based on the analyses of air emissions (both chemical compounds and
microorganisms) from the operations, analyses of tile chemical constituents of the process
streams and observation of the operations '" This landfill received only residential waste, and
this limited the potential for exposure to hazardous materials.
When a municipality or landfill owner is examining the feasibility of landfill reclamation,
particular attention must be paid to project objectives. As discussed previously, landfill
reclamation can meet a number of fairly divergent objectives, and the advantages of meeting
these objectives should be factored into any feasibility study. There is an economic and
environmental value associated with avoided closure costs, recovery of landfill space, and energy
recovery of landfillcd waste. Based on the results of this MITE evaluation, recovery of soil is a
feasible goal, and there is only minimal potential for the recycling of reclaimed ferrous, plastic
and aluminum.
ACKNOWLEDGMENTS
The author wishes to acknowledge Charlotte Frola, Project Officer of the Solid Waste
Association of North America (SWANA). SWANA administers the MITE program for the
EPA. All characterization and analytical work was completed by Ed vonStein, Project Manager,
and George Savage, Vice President, CalRccovery, Incorporated. They were also the principal
authors of the final report and the quality assurance project plan. Thanks and appreciation is
extended to Bob Fahey and the Collier County Solid Waste Department for their effort in
planning and conducting this demonstration.
Single copies of the final project report "Evaluation of the Collier County, Florida Landfill
Mining Demonstration" (EPA/600/R93/163), on which this paper was based, can be obtained
from the Center for Environmental Research Information, 26 West Martin l.uthcr King Drive,
Cincinnati, Ohio 45268. (513) 569-7562.
REFERENCES
1. New York State Energy Research and Development Authority, Town of Edinhury Landfill
Reclamation Demonstration Project. Energy Authority Report 92-4, Albany, New York, 1992,
pp. 1-2.
2. R.I. Stcsscl, University of South Florida, Tampa, Florida, memorandum to Bob Fahey, 1991.
3. E. vonStein, G. Savage, Evaluation of the Collier County. Florida landfill Mining
Demonstration. EPA/600/R93/163, U.S. Environmental Protection Agency, Cincinnati, Ohio,
1993, pp 16.
4. E. vonStein, G. Savage, Evaluation of the Collier County. Florida Landfill Mining
8
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44-KI'l 411.n I
Demonstration. EI'A/h00/R93/ l(>3, U.S. I "11 vi r< > time ill ;il Protection Agency. ( incinnati, Ohio,
199.3, pp 14.
5. E. vonStcin. Ci. Savage, Evaluation of llie Collier Cnunlv. Florida l-amlfill Mining
Demonstration. EPA/600/R9.3/163, U.S. Environmental Pmtection Agency, Cincinnati, Ohio,
1993, pp 17.
6. I vonStein, (>. Savage, Evaluajion ..of the Collier County. Morula landfill M in illy
Demonstration. EPA/000/R93/l(i3, U.S. Environmental Protection Agency, Cincinnati, Ohio,
1993, pp 17.
7. Rule 17-70'): Criteria for the Production and Use of Compost Made frotn Solid Waste.
State of Florida Department of Environmental Regulation, IW.
8. E. vonStein, (i. Savage, Evaluation of the Collier County. Florida landfill Mining
Demonstration. EPA/600/R93/|fi3, U.S. Environmental Protection Agency, Cincinnati, Ohio,
1993, pp 30.
9. S.E. Environmental Consultants, Inc., Air Quality Survey Report. EPA/MITE Evaluation
Project, l-andfill Mining Technology Evaluation. Hollywood, Florida, June IS, 1992, pp 2.3
10. S.E. Environmental Consultants, Inc., Air Quality Survey Report. EPA/MITE Evaluation
Project, landfill Mining Technology Evaluation. Hollywood, Florida, June IS, 1992, pp 20.
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Table I Mass Halance Summary
Stream No Material % by Weight
51 Soil Fraction (Trommel Under*) V) 30
52 Plastics 2 42
53 Ferrous 1 73
$4/$5 Aluminum/Residue 76()
S6 Additional Ferrous (a) 0 08
SI Non-Processible I7<)4
SR Finger Screenings 3 31
$9 Heavies 7 43
TOTAL 100
Table 2. Product Stream Purity, as Indicated hy Stream Characteri7a(ion
Component
Soil (SI)
Ferrous
Plastic (S2)
Aluminum
(.SW/r)1"
(S3)
(242r/r)
/Residue
(1.73%)
(S4/S5)
(l.WVc)
Paper A Paperboard
0.6
1.2
14 3
15.2
Plastics
0.3
9.0
74,5
24.3
Yard Waste
I.I
0.2
1.5
').?
Ferrous Metals
0.0
81.5
0.1
0,4
Rubber/leather
0.0
0.0
0.0
4.9
Textiles
0.0
1.2
4.4
8,3
Wood
0.0
2.0
0.2
15,2
Food Waste
0.0
0.0
0.0
0.1
Aluminum
0.0
0.5
0.7
5.5""
Glass
1.9
0,2
0.1
3.3
Incrts (Soil)
1)4,2
1.6
0.9
8.0
Non-Ferrous Metals
0.0
0.1
0.0
0.7
Unidentifiable
2.0
2.3
3.4
4.3
TOTAI.
100.0
100.0
100.0
100.0
These numbers represent the average weight percent nf each stream as a fraction of the total amount of mincil
material.
Separation of aluminum whs not possible with the existing equipment. This represents the majority of the
aluminum.
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Table 3. Distribution of Target Material among the Product Streams.
Finger
Additional Aluminum/ Screen Air Knife
Target
Soil
Plastics
Ferrous
Ferrous
Residue rt"
Unders
Heavies
Material
(SI)
(S2)
(S3)
(S6)
(S4/S5)
(S8)
(S9)
TOTAL
Plastic
4.0 %
42.1%
3.7%
0.2%
43.7 %
2.6%
3.7 %
100%
Ferrous
0.0%
0.0%
74.2%
3.2%
1.6%
0.5%
20.5%
100%
Aluminum
0.0%
4.3%
2.2%
0.0%
<51.3%
0.0%
2.2%
100%
Inert
94.7%
0.0%
0.1%
0.0%
1.0%
u p
1
rQ
3.7%
100%
The "Additional FeiTous"stream was produced by an additional ferrous magnet on the Aluminum/Residue CS4,'S5) conveyor
5 This stream contained the majority of the aluminum, since it could not be isolated by the edd> current scparalor.
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Table 4. Comparison of Heavy Metal Limitations with Recovered Soil.
Metals (mg/kg dry wt)
Florida'"1
Recovered Soil
Fraction (Sl)'h|
Cadmium
< IS
1.7
1 cad
< S(Mt
50.0
Mcrairv
N/A
0.2
Zinc
< WO
197.5
Chromium
N/A
1.1.X
Nickel
<50
3.9
Copper
<450
32.0
1,1 Honda's Heavy Metal Criteria fur Compost; Code I Source PAC Chapter 17-70*' SS()(|)(e)
|V| Average nf 4 samples collected daily for each ol three consecutive days.
Table V Trace/Toxic Chemical Composition of the Recovered Soil
Moisture 25 95 %
pH 7 22 %
Ammonia Nitrogen 128 0 mg/kg
--Total Organic Nitrogen 1,325 mg/kg
-TKN 1.453 mg/kg
Nitratc-N 46 8 mg/kg
Phosphorus. Total 421 mg/kg
Phosphate, Ortbo (as P) 0 76-. x- 0 80 mg/kg
Potassium. Total 205 tng/kg
Total Solids 74 I %
Total Volatile 6 63 %
BOD, 1,253 mg/kg
COD 74.500 mg/kg
All values arc numerical avenges All mg/kg are dry weight units
Greater or less than ranges (e g . a-'\'b) are based on detection limits reported hv the laboratory
Overall ranges (c g . a-h arc the lowest and highest values, respectively. reported by the laboratory
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Table 6 An Quality Monitoring Results1*'
Parameter
[ Inits
Most
Stungent ,hl
Stuiuhnd
Downstream I Ipstieam
Grizzly
Nuisance Dust
Total
Respirahlc
Microbial Agents
Bacteria
Fungi
Metals (a)
Calcium
Lead
Fibers
Other
nig/m*
nig/m'
CFU/ni'
CFUW
ug/ni1
iig/m1
fibcrs/cc
10 A
O/A
1000 0
1,000 ()
2 000 A
50 ()
N/A
¦0 10
0 21
<4 <4
4017
• 10 2
¦ 0 %
• 0 0005
0 10
0 17
0
5087
10 2
0 71
0 0101
Trommel
Sample Number
Nuisance Dust
Total
Respirable
Microbial Agents
Hactei la
Fungi
Metals
Calcium
Copper
Lead
mg/m1
mg/m'
CFl l/m'
CF1 i/m*
ug/m1
ug/m1
ug/m'
10
5
A
A/O
1.000 ()
1.000 ()
2,000
1.000
50
A
O/A
O
• 0 2S
¦ 0 21
881
5577
20
¦ 10
• I 2
• 0 ! 0
¦ 0 10
0
5687
• 10 2
¦ 7 I
• 07
Values that arc presented arc averages of all locations sampled
Standards arc for comparison only, and arc not regulators limits Standards lislcd arc as follows
O • OSHA. N - NIOSH. A - ACCilH
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Soil
Solid
Waste
Grizzly
(SI)
Ferrous Residue
Trommel
I
(S3)
(S4/S5)
Magnetic
Air Knife
Plastics
(S2)
Non-processibles
(S7)
Finger Heavies
Screen (S9)
Unders
(S8)
Figure 1. Process Flow Diagram for the Landfill Reclamation Demonstration.
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TECHNICAL REPORT DATA
(Please read instructions on the reverse before comple' '
1. REPORT NO. 2.
EPA/fi00/A-
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