United States
Environmental Protection
Agency
Office of Research and
Development
Washington, DC 20460
Office of Solid Waste and
Emergency Response
Washington, DC 20460
vvEPA
SITE FACTS
Location: Brookhaven,
Mississippi
Laboratories/Agencies: U.S.
EPA National Risk Management
Research Laboratory (NRMRL),
U.S. Department of Agriculture
Forest Products Laboratory
(FPL), Superfund Innovative
Technology Evaluation (SITE)
Program, U.S. EPA Region 4
Media and Contaminants:
Pentachlorophenol (PCP) and
creosote in soil
Treatment: Lignin-degrading
fungi
Date of Initiative Selection:
Spring 1991
Objective: To evaluate the
effectiveness of lignin-degrading
fungi treatment for wood
preserving wastes
Bioremediation Field Initiative
Contacts: John Glaser and
Richard Brenner, U.S. EPA
NRMRL, 26 West Martin Luther
King Drive, Cincinnati, OH 45268
Regional Contact:
De'Lyntoneus Moore, U.S. EPA
Region 4, Waste Management
Division, 345 Courtland Street,
Atlanta, GA 30365
EPA/540/F-95/506G
September 1995
Bioremediation Field
Initiative Site Profile:
Escambia Wood
Preserving Site
Background
The Escambia Wood Preserving Site located in Brookhaven, Mississippi, is a
former wood preserving facility that used pentachlorophenol (PCP) and creo-
sote to treat wooden poles. Located on the site are two pressure treatment
cylinders, a wastewater treatment system, five bulk product storage tanks,
seven condenser ponds (including a 3,000,000-gal., unlined primary surface
impoundment), and excavated soil materials containing process chemicals
from past spills. In April 1991, U.S. EPA Region 4 initiated a removal action to
eliminate all sources of potential releases to the environment.
In the fall of 1991, PCP-contaminated soil from previous spill events was
used to evaluate multiple soil treatment regimes involving three different
fungal strains during an 8-week treatability study. A follow-on field-scale
demonstration study using one specific strain of lignin-degrading fungi was
conducted over a 5-month period (June to November 1992). Both studies
were carried out by the U.S. EPA Risk Reduction Engineering Laboratory
(RREL) (now the National Risk Management Research Laboratory
[NRMRL]) and the U.S. Department of Agriculture Forest Products Labora-
tory (FPL) under the Superfund Innovative Technology Evaluation (SITE)
Program with support from the Bioremediation Field Initiative.
Site Characterization
In preparation for conducting a treatability study, candidate contaminated
source soils from the site were sampled at the surface in June 1991. Com-
posite soil samples were analyzed for PCP and other volatile and semi-vola-
tile organics. The composite samples contained elevated concentrations of
44 organic compounds, 12 of which are hazardous constituents of K001
waste. PCP concentrations were found to range from 25 to 342 mg/kg, with
an average of 143 mg/kg. Contaminant concentrations varied greatly
within the sampled soil. Subsequent excavation of these soils to provide
sufficient quantities of material for the treatability and demonstration stud-
ies showed increasing concentrations of PCP with depth, eventually en-
countering concentrations in excess of 5,000 mg/kg.
Treatability Study
The treatability study compared 10 treatments, combining three fungal
species, three inoculum loading levels, and the appropriate controls. The
experimental method combined a randomized complete block (RGB) de-
signed without replication and a balanced incomplete block (BIB) design
with treatment replicated four times. Eleven 10-ft by 10-ft plots, each
holding about 4 tons of soil, were constructed. In the RGB design, six of the
plots each received a separate treatment. In the BIB design, each of the five
remaining plots was divided by interior borders into four 2.5-ft. by 2.5-ft
Printed on paper that contains at least
50 percent recycled liber.
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split plots. These plots were used to evaluate one of the
treatments from the RGB design and four additional
treatments.
Excavated soil was mechanically sieved to pass through
a 1-in. screen, mixed, and placed in the plots to a depth
of 10-in. The plots were then inoculated with the fungi.
After inoculation, each plot periodically was irrigated
and tilled with a garden rototiller. Wood chips were
added to each plot to provide a substrate to sustain
growth of the fungi. Figure 1 is a schematic of the soil
preparation, showing the treatment plots. Treatment
with Phanerochaete chrysosporium resulted in an average
69 percent reduction in PCP for initial concentrations in
excess of 1,000 mg/kg, while an average reduction of 89
percent was achieved with Phanerochaete sordida with
initial PCP concentrations of 600-700 mg/kg.
Demonstration Study
A field-scale demonstration study was conducted in 1992
using the lignin-degrading fungus P. sordida to treat PCP
and 13 polycyclic aromatic hydrocarbons (PAHs) found in
the contaminated soil. P. sordidawas selected based on the
results of the treatability study and its natural occurrence
in soil. The soil excavated for this study had much higher
PCP concentrations (up to 5,200 mg/kg) than that used in
the treatability study, although the average concentration
was decreased to approximately 1,000 mg/kg by dilution
with clean soil. The contaminated soil was placed in a 70-ft
by 100-ft soil treatment bed and two 25-ft by 50-ft control
beds. The treatment bed was inoculated with 10 percent
dry (w/w) fungal hyphae and inoculum substrate/soil.
No amendments were added to one of the control beds,
while the other was formed by blending in 10 percent dry
(w/w) sterile inoculum.
Depletion of targeted compounds in the treatment bed
and the two control beds was measured over a 20-week
period from June to November. A 64 percent reduction
in PCP concentration was achieved in the fungal treat-
ment bed compared to 26 percent in the sterile inocu-
lum-amended control bed and 18 percent in the
non-amended control bed. Substantial reductions in the
concentrations of 3- and 4-ring PAHs were noted in all
three beds, although depletion of 4-ring PAHs was greater
in the treatment bed than in the control beds. The 5- and
TREATMENT PLOTS
Figure 1. Schematic of soil preparation, from excavation to screening,
mixing, placement in treatment plots, and inoculation with fungi.
6-ring PAHs were not significantly diminished in either
the treatment or the control beds. The extent of treat-
ment was controlled by two factors: low biological
activity of the fungal inoculum as determined by ergos-
terol measurements at the beginning of the study and
unfavorable weather conditions that severely curtailed
the desired tilling schedule for the soil beds.
Status
Although the treatment efficiencies achieved in the 5-
month field-scale demonstration study at Brookhaven
were somewhat disappointing after the highly promis-
ing treatability study, the demonstrated ability of lignin-
degrading fungi to remove significant quantities of PCP
at an initial concentration of approximately 1,000
mg/kg is considered encouraging. This concentration
is roughly 10 times greater than concentrations typically
attempted with bacterial-based treatments. The exces-
sive rainfall encountered at Brookhaven, which fre-
quently interfered with regularly scheduled tilling, may
have resulted in oxygen depletion in the treatment bed,
leading to loss of fungal mass and activity. This envi-
ronmental consequence suggests that future applica-
tions of fungal treatment technology may need to avoid
soil bed configurations to prevent weather-related con-
straints. Current costs of fungal treatment operations
are estimated at $150-200/ton of soil. Reductions in
inoculum mass requirements and costs are anticipated
as new inoculum formulations and application tech-
niques are developed.
The Bioremediation Field Initiative was established in 1990 to expand the nation's field experience in bioremediation technologies.
The Initiative's objectives are to more fully document the performance of full-scale applications of bioremediation; provide
technical assistance to regional and state site managers; and provide information on treatability studies, design, and operation of
bioremediation projects. The Initiative currently is performing field evaluations of bioremediation at eight other hazardous waste
sites: Libby Ground Water Superfund site, Libby, MT; Park City Pipeline. Park City, KS; Bendix Corporation/Allied Automotive
Superfund site, St. Joseph. MI: West KL Avenue Landfill Superfund site. Kalamazoo, MI; Eielson Air Force Base Superfund site,
Fairbanks, AK; Hill Air Force Base Superfund site, Salt Lake City, UT; Reilly Tar and Chemical Corporation Superfund site, St.
Louis Park, MN; and Public Service Company. Denver. CO. To obtain profiles on these additional sites or to be added to the
Initiative's mailing list, call 513-569-7562. For further information on the Bioremediation Field Initiative, contact Fran Kremer,
Coordinator. Bioremediation Field Initiative. U.S. EPA, Office of Research and Development, 26 West Martin Luther King Drive.
Cincinnati, OH 45268; or Michael Forlini, U.S. EPA, Technology Innovation Office, Office of Solid Waste and Emergency Response,
401 M Street. SW.. Washington. DC 20460.
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