United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA/600/S2-86/035 Aug 1986
Project Summary
Evaluation and Disposal of
Waste Materials Within 19
Test Lysimeters at Center Hill
Riley N. Kinman, Janet Rickabaugh, Jean Donnelly, David Nutini,
and Martha Lambert
A study was conducted to evaluate
the physical, microbiological, and
chemical conditions of 19 experimental
landfills after the completion of a ten-
year-long municipal refuse/industrial
sludge codisposal project. The simu-
lated landfills were constructed in 1974
and 1975 and operated until September
1983. Data collected during this termi-
nation study (June 1984) included ob-
servations of overall test cell condi-
tions; chemical analysis of final
leachate, refuse, and bottom gravel;
physical analysis of refuse, gravel, and
clay conditions; microbiological analy-
sis of the refuse; and in-place perme-
ability and specific yield of the refuse.
Comparisons between municipal
refuse-only cells and municipal refuse/
industrial sludge codisposal cells were
made in order to evaluate the effect the
industrial sludges had on the decompo-
sition process.
The codisposal cells did not appear to
be different from the municipal refuse-
only cells in terms of any of the parame-
ters analyzed. Large numbers of aero-
bic, anaerobic, and facultative
microorganisms, many of which were
pathogens, were found in both types of
cells. It appeared that the decomposi-
tion process was more inhibited by the
presence of intact plastic or paper bags
and other protective wrappings than by
the presence of sludges from battery
production, plating operations, water
softening, paint pigments, solvent-
based paints, petroleum processing or
municipal wastewater treatment. Iden-
tifiable food wastes and other readily
biodegradable materials, including
fecal matter in disposable diapers, were
found protected from decomposition
by such wrappings.
This Project Summary was devel-
oped by EPA's Hazardous Waste Engi-
neering Research Laboratory, Cincin-
nati, OH, to announce key findings of
the research that is fully documented in
a separate report of the same title (see
Project Report ordering information at
back).
Introduction
Long-term experimental landfill stud-
ies commonly produce vast quantities
of data on characterization of the refuse
prior to cell loading and leachate and
gas analysis over the life of the study.
However, relatively little data are avail-
able on the characterization of the waste
upon completion of the study. The ter-
mination of this codisposal lysimeter
project provided an opportunity to in-
vestigate the physical, microbiological,
and chemical components of refuse in
its in situ state after 10 years. Nineteen
experimental lysimeters 12 feet high
and 6 feet in diameter wore packed with
6000 to 10,000 pounds of refuse and ref-
use/industrial sludge combinations.
Table 1 describes the contents of each
test lysimeter. The lysimeters weie lo-
cated at the Center Hill Solid and Haz-
ardous Waste Research Facility in
Cincinnati, Ohio. Fifteen of the cells
(designated cells 1 through 15) were lo-
cated in a cleared area behind the facil-
ity. They were buried in the ground to
within 6 inches of their tops. The other
test cells (designated cells 16 through
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Table 1.
Test Cell
Cell Contents
Contents
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Municipal Refuse
Municipal Refuse
Municipal Refuse
Municipal Refuse
Municipal Refuse
Sewage Sludge
Municipal Refuse
Sewage Sludge
Municipal Refuse
Sewage Sludge
Municipal Refuse
Calcium Carbonate
Municipal Refuse
Petroleum Sludge
Municipal Refuse
Battery Production Waste
Municipal Refuse
Prewetted with Water
Municipal Refuse
Electroplating Waste
Municipal Refuse
Inorganic Pigment Waste
Municipal Refuse
Chlorine Production Brine
Sludge
Municipal Refuse
Polio Virus
Municipal Refuse
Municipal Refuse
Solvent Based Paint
Sludge
Municipal Refuse
Municipal Refuse
19) were located in the high bay of the
facility.
The following objectives were estab-
lished in order to fully evaluate the con-
dition of the ten-year-old refuse and
lysimeters: 1) Perform an in-depth mi-
crobiological analysis of the refuse, in-
cluding routine indicator analyses and
characterization of a certain percentage
of the total number isolated, examina-
tion for fungi, methane-producing bac-
teria, Clostridium. and, finally, total
plate counts distinguishing between
aerobic and anaerobic bacteria, 2) De-
termine the in-place permeability and
specific yield of the refuse, 3) Perform
observations on channeling that may
have occurred through the refuse,
4) Evaluate the coal tar epoxy used to
line the inside of the lysimeters, 5) Eval-
uate the seals around probes and infil-
tration lines on the lysimeters, 6) Ob-
serve any layering of the refuse, and
7) Analyze the chemical components of
the refuse, gravel and the final leachate
from the cells.
Not all tasks were performed on all 19
test cells. Rather, representative sub-
groups were selected for the various
tasks.
Procedures
All refuse removal was performed by
hand by a team of three researchers.
Three separate 50-pound samples were
composited for chemical analysis from
across the surface of three distinct loca-
tions in each cell sampled (top, middle,
bottom). The bulk chemical analysis
samples were dried at 75°C in the as-
sampled condition until the sample
reached constant weight. Each sample
was coarsely ground, then finely
ground. A well-mixed subsample was
dried at 75°C to drive off any remaining
moisture. All chemical analyses were
performed on subsamples of finely
ground refuse. Standard methods were
selected for all chemical analyses.
The microbiological samples con-
sisted of five grab samples composited
to a total of about one kilogram at each
of the same three sampling locations.
Large items such as bottles, plastic toys,
cans, etc., were intentionally avoided in
the microbiological samples. During the
sampling procedures, numerous dis-
posable diapers were encountered con-
taining fecal matter. In order to evaluate
the impact of the diapers on the overall
microbiology of the refuse, a composite
diaper sample replaced the composite
refuse sample at six of the microbiolog-
ical sample locations. All microbiologi-
cal analyses were standard methods
with the exception of the methane bac-
teria analysis. This was essentially a
qualitative analysis in which the gas
produced by the bacteria was analyzed
for methane, indicating the presence or
absence of methane-producing bacte-
ria.
Visual observations on the condition
and appearance of the refuse, including
any channeling or layering, were
recorded in field notebooks as well as
through extensive photographs.
Results and Discussion
The test cells themselves withstood
the rigors of the ten-year study with
varying success. All cells were coated
on the inside with a coal tar epoxy lining
to prevent corrosion. The linings were
in excellent condition in all cells. Most
of the seals around the lysimeter lids,
water infiltration lines, and gas and tem-
perature probes were cracked and
therefore not gaslight. Many of the cells
had a fiberglass coating on the inside
bottom of the tank. Four of the 15 cells
with the fiberglass seal showed splitting
or some breakdown of the fiberglass.
The remaining 11 cells with fiberglass
seals were in good condition. Three of
the four inside lysimeters had white-
painted bottoms that were in excellent
condition, and the remaining cell had a
coal tar epoxy bottom that was also in
excellent condition.
In general the cell contents were very
damp and appeared as a black tar-like
mass with some easily recognizable
items (i.e., cans). There were many
paper and plastic bags with refuse in-
tact. A number of organic products were
protected from degradation in this man-
ner and were readily identifiable. Some
of the organic products found included
green grass clippings, potatoes,
chicken, hot dogs, cheese, chocolate
candy, bacon, and carrots. After the ref-
use was sorted and the tar-like mass
was cleaned off, many other readily
identifiable items were found. Among
these were plastic items, stainless steel
flatware, legible books and magazines,
cloth (both synthetic and natural) with
fibers still strong, coins, wooden toys,
rubber tires, and a ten-dollar bill.
There were no clear layers of waste
within the cells except in cell 18, even
though the industrial sludges had been
added in distinct layers. The paint
sludge in cell 18 did not appear to
undergo any decomposition and was
still clearly visible as a distinct layer.
The chlorine production brine sludge in
cell 14 was still in the original plastic
bags. Although there were distinct
pockets or layers of the sludge, the be-
havior of the sludge was not considered
conclusive, since it was not available for
decomposition.
There was no evidence of channeling
through the refuse in the lysimeters ex-
cept in test cell 9, where the petroleum
sludge was codisposed. Refuse coated
with the sludge was relatively dry.
Water was clearly channeled around the
petroleum sludge.
Microbiology
The microbiology was designed to
determine the ability of pathogenic or-
ganisms to survive long-term exposure
in a landfill and to determine which or-
ganisms were actively stabilizing the
waste. Microbiological enumerations
showed no clear trends from sample
level to sample level, nor were there any
clear differences in relative numbers of
microorganisms found in refuse-only
cells and codisposal cells. Diaper sam-
ples were found to contain levels of mi-
-------
croorganisms similar to non-diaper
samples. Relatively high numbers of all
organisms analyzed were found in all
samples. Figures 1 and 2 indicate the
results from the total aerobic plate
counts and fungi levels using Rose
Bengal agar. Relative levels were simi-
lar for all analyses performed. The cell
number is included by the results to em-
phasize the lack of any recurring trends
in any of the cells. These results also
show no significant difference between
codisposal cells and refuse-only cells.
An attempt was made to isolate and
identify all of the anaerobes, gram neg-
ative rods, and fungi found in the sam-
ples. Some difficulties were encoun-
tered with organism survival; therefore,
additional species were undoubtedly
present. A total of 13 different species of
Clostridium, 34 different species of
fungi, and 23 different species of gram
negative rods were identified in the
waste. Identified microbes included
known pathogens which can be seen in
Table 2.
Permeability and Specific Yield
In-place permeabilities and specific
yield were determined on four of the 19
test cells. These four cells included test
cell 2, the primary control cell; test cell
1, which had the least moisture added
throughout the project; test cell 4, with
the most moisture added; and test cell
16, which was located in the high bay
rather than outside, as were the other
three cells. Results of these two tests
are shown in Table 3.
The permeability measurements
were determined with a constant head
of from 2.3 to 3.6 feet, depending on the
cell. Permeabilities were essentially the
same for the four cells tested. Perme-
abilities of this absolute magnitude are
commonly found in sands and gravels.
These tests indicated that under the
conditions stated, leachate would move
through the landfill rather quickly. Al-
though this estimate of permeability
would tend to be more similar to a full-
scale landfill than laboratory measure-
ments, care should still be exercised
when extrapolating to full-scale condi-
tions, since several test conditions
would probably differ from those cre-
ated in the lysimeters.
Specific yield varied from 6.37 ft3/yd3
in test cell 1 to 3.20 ft3/yd3 in test cell 4.
It appears that the higher moisture rate
accelerated decomposition and pro-
duced a finer particle size mass that
could retain more water or leachate
than those receiving less moisture.
Total Plate Count
Aerobic
12
11-
10-
^ 9-
I
I
7 -
- 6-1
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Table 2. Pathogenic Organisms Identified in Refuse
Organism
Diseasea-b-c
Clostridium
Fungi
Gram Negative
Rods
C. bifermentans
C. botulinum
C. difficile
C. histolyticum
C..novyi
C. perfringens
C. ramosum
Aspergillus fumigatus
Aspergillus niger
Aureobasidium sp.
Monosporium apoispermum
Madurella sp.
Trichophyton sp.d
Fonsecaea sp.
Epidermophyton floccosum
Aspergillus nidulans
Aspergillus flavus
Aeromonas hydrophila
Klebsiella pneumonias
Klebsiella ozaenae
Acinetobacter sp.
Moraxella kingii
Yersinia enterocolitica
Yersinia intermedia
Alcalcigenes sp.
gas gangrene (wounds)
food poisoning
infant botulism
fatal diarrhea
gas gangrene
gas gangrene
food poisoning
gas gangrene
intra-abdominal infections
pulmonary aspergillosis
fungus-ball (lungs)
swimmers ear
allergies
mycetoma
pulmonary infection
mycetoma
ringworm
chromomycosis
skin and nail infections
mycetoma
pulmonary aspergillosis
wound infections
diarrhea
wound infections
wound infections
meningitis and septicienum
wound infections
gastroenteritis
mesenteric adenitis
gastroenteritis
mesenteric adenitis
urinary tract infections
a Davis et al. (1980).
b Koneman et al (1983).
c Lennette et al (1980).
d Pathogenic species.
Table3.
Test Cell
1
2
4
16
Permeabilities and Specific Yield
Permeability* Specific Yield
(cm/sec) (ft3/yd3)
1.26 x W~2
1.14* 10~2
1.00 x JO'2
7.05 x 70-*
6.37
5.88
3.20
4.10
Table 4. Chemical Analysis of Refuse
(Dry Weight Basis)
Minimum Mean Maximum
*Mean of three replicate results.
Chemical Analyses
In general, chemical analyses of the
refuse substantiated the results of the
physical examinations (Table 4). Con-
siderable carbon-containing materials
remained in all cells. The mean TOC
value for the refuse-only cells was
1270 g/kg on a dry weight basis and
1260 g/kg for the co-disposal cells.
Mean COD values further substantiated
the presence of considerable chemical
oxidizable material in the cells after 10
% Moisture
COD g/kg
TOC g/kg
TKN g/kg
Cl g/kg
45.6
305
597
6.93
1.18
57.9
1760
1360
16.0
3.0
68.6
3290
2110
33.9
11.4
years. The mean COD value for the
refuse-only cells was 1750 g/kg on a dry
weight basis and 1520 g/kg for the co-
disposal cells on a dry weight basis.
Considerable amounts of chloride and
nitrogen remained in the waste materi-
als in all cells. Nutrients should not have
been limiting in any lysimeter.
The bottom gravel appeared to be in
excellent condition in all cells. There
was some intermingling and sticking of
waste materials to the gravel at the
waste gravel interface, but basically the
gravel was like new. Some thin layers of
black residue were on the gravel. Analy-
sis of the gravel residue indicated the
presence of sulfide in some cells and
residual oxidizable organics in the
residue from all cells.
The final leachate from the cells did
not change significantly from the final
sampling during the actual ten-year
project in April 1983 to June 1984, when
leachate was collected for this study.
Based on the results obtained, no clear
conclusion can be drawn concerning
the effect of the lack of moisture on
leachate quality.
Summary and Conclusions
Industrial sludges did not prevent bio-
logical decomposition, nor did these
sludges eliminate indicator organisms
that were found in relatively high levels
in all cells. Many of the organisms iso-
lated are known pathogens. Even after
10 years of disposal, many items were
easily recognized and undoubtedly in
their "as disposed of" condition. Dis-
posable diapers containing fecal matter
were found intact in all test cells. Protec-
tive wrappings such as plastic and
paper bags had protected food wastes
and other readily biodegradable mate-
rial from decomposition. In fact, the pro-
tective wrappings appeared to be more
inhibitory for biodegradation than the
industrial sludges, indicating that plas-
tic and paper bags should be torn open
as much as possible to permit readily
biodegradable material to decompose
in the landfill environment. Leachate
from refuse-only cells was not apprecia-
bly different from leachate drained from
the codisposal cells. Moisture content
positively affected decomposition. The
higher-the moisture content, the greater
the decomposition found.
The full report was submitted in fulfill-
ment of Contract 68-03-3210, Task 4, by
the University of Cincinnati under the
sponsorship of the U.S. Environmental
Protection Agency.
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Riley N. Kinman. Janet Rickabaugh. Jean Donnelly, David Nutini, and Martha
Lambert are with the University of Cincinnati, Cincinnati, OH 45221.
Joseph K. Burkart is the EPA Project Officer (see below).
The complete report, entitled "Evaluation and Disposal of Waste Materials Within
19 Test Lysimeters at Center Hill," (Order No. PB 86-176 336/AS; Cost: $16.95.
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
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