United States
Environmental Protection
Agency
Robert S. Kerr Environmental
Research Laboratory
Ada OK 74820
Research and Development
EPA/600/S2-85/134 Feb. 1986
v>EPA Project Summary
Field and Laboratory
Evaluation of Petroleum Land
Treatment System Closure
M. R. Overcash, W. L. Nutter, R. L. Kendall, and J. R. Wallace
The objectives of this research were
to measure and interpret the effect of
surface soil changes on the underlying
soil and the quality of runoff water from
petroleum landfarms undergoing simu-
lated closure. Four landfarm waste/
soils were studied for chemical trans-
formations in the greenhouse with one
of the same sites tested in the field for
runoff quality and waste stabilization.
The results obtained at the field site
closely paralleled the greenhouse results
for the same refinery. The field results
over two years showed insignificant
downward migration of the organics
and heavy metals studied. On the basis
of aggregate measures of organics,
several compound groups of organics,
as well as specific organic species, the
closure period of two years in this study
allowed significant reductions in waste/
soil concentrations. These reductions
leveled off or became more slowly
changing in the second year of the
study. No substantive leaching was
observed for inorganic or organic
parameters measured in both the green-
house and the field studies associated
with this project. Vegetation improved
runoff quality. Some adverse effects on
seed germination and vegetation estab-
lishment were observed with soil/waste
mixtures in greenhouse studies.
This Project Summary was developed
by EPA's Robert S. Kerr Environmental
Research Laboratory, Ada, OK, to an-
nounce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
Land treatment is the treatment and
stabilization of wastes applied to the soil-
vegetation complex by biological, chem-
ical, and physical processes. In consider-
ing the closure of a hazardous waste land
treatment system the U.S. Environmental
Protection Agency (EPA) has stressed the
importance of controlling migration of
constituents into ground water along with
release of airborne particulates (EPA
1981). The primary focus of this project
was the behavior of petroleum land
treatment systems in the closure period.
That is, after active use for treating typical
petroleum refinery sludges or wastes,
use of the land application area is discon-
tinued. During this period, shortly after
discontinuing use, practices are employed
which in the context of RCRA are referred
to as site closure. Closure activities
continue until certain environmental
standards are achieved at which time a
post-closure period begins.
In the context of closure, the EPA
(1981) established certain objectives:
1. control the migration of leachate
from the zone of active incorpora-
tion into ground water;
2. control the release of contaminated
runoff to surface water;
3. control the release of airborne par-
ticulate contaminates; and
4. comply with the standards estab-
lished for food-chain crops.
Further, a series of techniques or
approaches were suggested for achieving
these objectives (EPA 1981).
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1. "no action" provided the (closure)
plan is acceptable from the human
health viewpoint and is environ-
mentally sound,
2. the establishment of a permanent
vegetative cover, i.e., in-situ con-
version to usable land,
3. the capping of the landfarm area
with a layer of material which will
control infiltration and wind and
water erosion, i.e., a landfill-type
closure, and
4. the removal and landfillingthezone
of incorporated waste.
As a part of the decision-making pro-
cess leading to the specific research
project objectives, these four techniques
were evaluated in some detail in a litera-
ture assessment (Kendall, et al., 1981).
The report concluded the following:
1. There were four principal approach-
es to design and management of a
closed site.
2. These approaches and the respec-
tive total five year costs for a
standard site were:
a. no-action on site but with runoff
collection and monitoring ($143,
000)
b. vegetation establishment and
runoff collection and monitoring
($193,000)
c. establish an impermeable clay
cap ($707,000)
d. removal of surface soil to an
approved landfill ($1,516,000)
3. A well managed petroleum land
treatment area achieving substan-
tial assimilation of waste constitu-
ents would not be expected to pose
major closure difficulties.
The major research objective of this
project was to measure and interpret the
surface soil zone changes in relation to
the quality of runoff water from petroleum
landfarms undergoing simulated closure.
The experimental effort was directed at
measuring the changes in the composi-
tion of four petroleum landfarm waste/
soil mixtures over a two-year closure
period in the greenhouse. Simultaneous-
ly, one of these waste/soil mixtures was
monitored at the original landfarm and
runoff liquid samples collected to meas-
ure this aspect of land treatment site
closure.
Secondary objectives adopted for the
study included sampling two immediately
lower soil zones at the field site for
constituent migration. In addition, a lim-
ited evaluation relating to establishing a
grass vegetation on a closed land treat-
ment area was conducted.
Materials and Methods
Four sites for the greenhouse study
were selected. In general, petroleum land
treatment areas are operated with rates
of application
1. established to optimize oil waste
treatment, or
2. to largely obviate extended closure
periods.
Since the majority of petroleum land
treatment systems use the former oper-
ating mode, a single field site was selected
to reflect these practices. The field site
would provide over an extended period of
time the opportunity to measure changes
in the surface conditions. A rainfall
simulator was used to produce runoff
liquid from nearly identical events spaced
over approximately six-month periods for
2.5 years. At the location chosen multiple
test plots were established within vege-
tated and non-vegetated waste amended
areas and non-vegetated control areas.
The landfarm conditions studied were
broadened by adoption of a parallel
greenhouse investigation. Four petroleum
landfarms with areas available for closure
were selected to collect surface soils for
experimentation. One of these was the
field location so that some comparative
relation could be developed between
greenhouse and field information. Such
multiple site experiments in a greenhouse
were much less costly than equivalent
field studies. In the greenhouse the
variables of vegetated waste/soil, non-
vegetated waste/soil, and non-vegetated
control soil were used in an analogous
fashion to the field. However, only the soil
changes over time were investigated in
the greenhouse, with runoff liquid studies
confined to the larger field study.
From the general experimental system
described above, samples were taken at
approximately six-month intervals over a
period of two years from the implementa-
tion of closure status corresponding to
the summer of 1982. These samples
consisted primarily of surface waste/soil
material or runoff liquid with some vege-
tation samples also taken. For the primary
samples, the chemical constituents se-
lected for analyses were chosen to reflect
both the agronomic and environmental
requirements of the closure approaches
investigated. These parameters were in
three groups:
1. macro- and supplementary nutri-
ents and conditions important to
vegetation growth;
2. metals—the most prevalent criteria
for judging long-term closure status;
and
3. organic parameters reflecting ag-
gregate measures of organics and
oil, specific groups representing
fractions of petroleum-related
wastes, and specific compounds.
For the secondary objectives, the same
field and greenhouse soils were used.
Samples of the soil directly below the
zone of incorporation were taken in the
field and greenhouse and soil samples
from a third lower depth were taken from
the field. These additional mid- and lower-
depth samples were analyzed for a subset
of the parameters characterizing the
upper soil. This subset of parameters
were thus a measure of migration under
field and greenhouse conditions. In addi-
tion, a germination study was instituted
to assess the feasibility of establishing
vegetation during the land treatment
closure period.
Results
Behavior of Aggregate Organics
Three measures of aggregate organic
concentrations were used to establish
the initial conditions and closure period
behavior:
1. total organic carbon (TOC);
2. oil and grease (O&G); and
3. total chromatographable plus grav-
imetric organics (TCO+GRV).
An initial decrease followed by an
asymptote in aggregate organic param-
eter concentration is characteristic of
general organic behavior in soil. However,
the basis for the organics asymptote could
not be determined from this research.
The asymptote was in all cases consider-
ably above the level of control soils.
Behavior of Fractions of the
Total Organic Extract
The organic material extracted from the
waste/soil mixtures was split into a group
(TCO) with a boiling point generally lower
than 303°C and a group (GRV) with a
boiling point above this temperature. Each
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of these two groups was fractionated into
the additional subcategories:
1. aliphatics (LCH);
2. aromatics (LCA); and
3. polar species (LCX).
For the high boiling group (GRV) the
aliphatic and aromatic losses were 3,000
to 20,000 mg/kg soil (6 to 40 mt/ha) and
3,000 to 10,000 mg/kg soil (6 to 20
mt/ha), respectively. The lower boiling
group (TCO) evidenced a greater percent-
age loss, but on a mass basis was 1,000
to 2,000 mg/kg soil (2 to 4 mt/ha) for
aliphatics and 500 to 2,000 mg/kg soil (1
to 4 mt/ha) for aromatics.
Behavior of Inorganics
Over the experiment duration the total
metals were analyzed in waste/soil mix-
tures and in the control soils. The controls
were unchanged over these two years.
No differences between waste/soils with
or without vegetation were found for total
metals. Examinations of total metals
concentrations over the two years show
that no changes occurred. That is, the
experiment consistency was such that
the expected conservation of total inor-
ganic constituent concentrations was
achieved. As with total metals, the control
soil soluble inorganics were found to
have remained essentially unchanged
over the two-year experiment.
Comparison of Behavior of
Constituents in Greenhouse
Waste/Soil Mixtures with Field
Waste/Soil Mixtures
Only a single landfarm soil was avail-
able for a direct comparison of the
constituent assimilative phenomena
under both field and greenhouse condi-
tions. The control soil in the greenhouse
plots and at the field site are essentially
the same throughout the two-year study
for all of the measures of aggregate
organics. For the waste/soil mixtures, it
was found that the TCO, GRV, TOC, and
the fractions of LCH, LCA, and LCX were
essentially the same between green-
house and field experiments (within data
variability). There were only two dates in
which directly comparative data on the
fractions (LCH, LCA, LCX) were available.
The similarity of field and greenhouse
concentrations continued over the span
of two years, thus the mass losses
(kg/ha-yr) were similar.
Oil and grease (organics extracted by
trichlorotrifluoroethane) was consistently
higher in soil concentration at the field
location when compared to the waste/soil
mixture kept in the greenhouse. Between
field and greenhouse experiments, this
O&G difference is small when compared
to the concentration differences between
waste/soil and control soils.
In overview of soluble and total inor-
ganics, there was a similarity between
comparable field and greenhouse condi-
tions. The field differences between
waste/soil mixtures versus control soils
remained the same as previously de-
scribed for the greenhouse plots.
Environmental Impacts
During Field Closure
Vertical Migration—Samples were col-
lected at the 25- to 50-cm depth in the
field as representative of the first zone to
evidence any leaching from the upper
waste/soil mixture. Examination of the
total inorganics, soluble inorganics and
the aggregate organic parameters re-
vealed no consistent increase at the lower
depth over the two-year closure period.
Runoff—During the course of the field
experiments five simulated rainfall events
were conducted to obtain runoff samples.
In these rainfall simulations the precipita-
tion intensity was constant. However, the
preconditions of the soil (moisture con-
tent) were determined by the climatic
rainfall pattern and thus could not be
controlled.
In the phenomena contributing to the
transport of chemical constituents from
rainfall impinging on the land surface
there are two counterbalancing effects
that determine the response of an area
containing a waste and the corresponding
control soil. These are:
1. the relative surface soil concentra-
tion of a specific chemical param-
eter between the landfarm area and
the control area; and
2. the effect of waste on the infiltra-
tion/runoff mechanism relative to
the control area without waste.
The higher the ratio of a constituent
concentration in the surface soil of a
waste treated area to that of the control
location, the greater the possibility that
the runoff liquid chemical concentration
from the waste application plots would
exceed that of the control plots.
In an effort to depict the nonlinear
relation between the various waste con-
stituent concentrations in the surface soil
and that in the runoff liquid a comparison
was made, Figure 1. The ratio of waste/
soil concentration to control soil concen-
tration was diagrammed versus the same
ratio measured in runoff liquid. As can be
seen from Figure 1, the very high surface
zone levels were not reflected in a similar
elevation above control for the runoff
impact. Note the soil ratio is a logarithmic
scale. As the character of the waste/soil
surface zone approaches that of the
control soil the runoff concentrations also
are essentially the same as that from
control plots. One can conclude that very
large ratios of surface soil concentrations
of a chemical to that of the control soil are
needed to have a major impact on runoff
liquid concentrations during landfarm
closure.
Conclusions and
Recommendations
The following summary statements
apply to the results of this two-year
simulation of petroleum landfarm closure
in the greenhouse and on field plots.
1. Field results at a closed refinery
land treatment (LT) system closely
paralleled the results obtained in a
greenhouse simulation of closure
using soil/waste obtained from the
same refinery. This being only one
comparative study, no firm conclu-
sion can be drawn as to whether
the green house studies using soil/
waste mixtures from three addi-
tional refineries would adequately
predict full-scale results at the
respective locations. However, it
can be concluded that greenhouse
simulation studies, which have
advantages in terms of cost and
controlled environment may be an
important aspect of full-scale clo-
sure evaluation at a LT system; and
at such time that results are statis-
tically comparable, emphasis might
be shifted to the greenhouse studies
at a considerable cost savings. It
can also be concluded that the
results of this study for one refinery
operation suggest that future com-
parative greenhouse/field studies
will show the predictive usefulness
of the greenhouse, leading hope-
fully to the emphasis being placed
on greenhouse simulation with
periodic field confirmation.
2. Based on two years of data collected
at one land treatment closure site,
closures having similar conditions
of waste soil and climate will have
insignificant downward migration
of the organics and heavy metals
studied.
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w
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w
I
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g
o
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o
c
3
CC
.o
to
TN
Cu.Cr
TOO and GRV.
TOO
Pb, Sr. Na. Ca. TOC
Nl, TP. B
K, Mg. Fe. Mn, A I. V, Ba
10 WO
Ratio Soil Concentrations in Waste/Soil to Control
WOO
Figure 1. Relation of surface soil and runoff concentrations.
3. Based on i\e\d results at one refinery
for two years, grass vegetation (as
opposed to no vegetation) will im-
prove runoff water quality by con-
trolling migration of eroded particu-
late material contaminated with
organic and inorganic constituents
originating from the waste/soil
mixture.
4. Based on greenhouse results re-
presenting four refinery land treat-
ment systems and three native
grasses, preliminary testing of soil/
waste mixtures and different
grasses is recommended to identify
adverse effects that may resu It from
incomplete germination and/or
grass kill.
5. Based on controlled greenhouse
studies of two-years duration, the
zone of soil/waste mixture for land
treatment closure will exhibit es-
sentially no change in total extrac-
4
table organics and in solubilizable
and total metals; the mixture will
also exhibit an asymptotic decline
with time to above background
levels in oil and grease and in total
chromatographable organics (i.e.,
boiling point <300°C).
6. For the 10 RCRA Appendix VIII
polynuclear aromatic hydrocarbons
(PNAs) analyzed in field and green-
house studies, the expected levels
in the surface soil/waste mixtures
(similar to those investigated) will
be <5 ppm. These levels may be
expected to decrease over two years
by <80%.
The research effort was jointly funded
by the EPA and American Petroleum
Institute.
References
Kendall, R. L, H. P. Arora, and J. R.
Wallace. Landfarm closure literature
review. Report to American Petroleum
Institute by Law Engineering Testing
Co., December 1981.
U.S. EPA. Hazardous Waste Management
System: General standards applicable
to owners and operators of hazardous
waste permit programs. Permitting of
Land Disposal Facilities: Land Treat-
ment, Background Document 3 (MS
1941.36). U.S. Environmental Protec-
tion Agency, Washington, DC, 1981.
. S. GOVERNMENT PRINTING OFFICE: 1986/646-116/20768
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M. R. Overcash, W. L Nutter, andR. L. Kendall are with Earth Systems Associates,
Marietta, GA 30064; and J. R. Wallace is with Law Environmental Services,
Marietta. GA 30067.
Fred M. Pfeffer is the EPA Project Officer (see below).
The complete report, entitled "Field and Laboratory Evaluation of Petroleum Land
Treatment System Closure," (Order No. PB 86-130 564/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:
Robert S. Kerr Environmental Research Laboratory
U.S. Environmental Protection Agency
P.O. Box 1198
Ada, OK 74820
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S2-85/134
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