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Session 2:
Site Assessment
Assessment
of Oil Contamination in Oil Trenches Located in Two
Contrasting Soil Types
Samira A. Omar,
Kuwait Institute for Scientific Research, Safat, Kuwait
Free-Phase
Soil Limits for Volatile Organic Compounds: Evaluation of
Sensitive Parameters, Site-Specific Variables and
Applicability for Establishing Cleanup Goals
Eric M. Cherry, Hull
& Associates, Inc., Dublin, OH
Expedited
Site Assessment at a Large Naval Fuel Terminal
Robert M. Magee,
Naval Facilities Engineering Command, Atlantic Division,
Norfolk, VA
An
Evaluation of Soil Background Concentrations in South
Boston
Martha L. Zirbel,
Metcalf & Eddy, Inc., Wakefield, MA
Assessment
of Oil Contamination in Oil Trenches Located in Two
Contrasting Soil Types
Dr. Samira A. S. Omar, Ph.D., Dr. Raafat Misak, Ph.D.,
Dr. Shabbir A. Shahid, Ph.D., Kuwait Institute for
Scientific Research
During Iraqi invasion and occupation of Kuwait the
Iraqi forces dug 120 trenches over a length of more than
200 km and filled with oil. They extend along the southern
border zone of Kuwait 10-14 km from the Saudi Arabian
border. These oil trenches are located in areas of
different soil types, different characteristics of soils
resulted into different levels and depths of oil
contamination. Two oil trenches were selected located in
two contrasting soil types. One soil type is loose sandy (psamments)
and the other is stable (calcids). The oil trenches were
dug with back hoe machine, the on-site investigation
revealed that the upper 90 cm depth in the sandy soil type
is visually clean loose sand (TPH-total petroleum
hydrocarbons 300ppm), a depth (90-95 cm) was identified as
very stable oil contaminated (TPH 10,000ppm) zone. The
zone from 95-140 cm was identified as sludge (TPH more
than 80,000 ppm), and below 140 cm it was oil soaked
calcrete (TPH 78,000ppm). The TPH decreases to 14300 pmm
at just belo 190 cm. Due to very hard nature of subsurface
soil it was not possible to dig further below 190 cm. The
TPH in control sites (50 m from the trench) ranges between
200-300ppm. The oil trench in a more stable soil (calcids)
was found to be contaminated upto the surface. The highest
contamination was at 0-60 cm (TPH 37,600 ppm), it
decreases to 19,800 ppm at 60-95 cm. Zone below 95 cm was
an oil soaked calcrete (TPH 19,200 ppm). The samples
collected from control sites 50 m away from oil trenches
show TPH upto 400 ppm. It is very clear that the level and
depths of oil contamination differs with soil types, and
suggests further investigation of oil trenches located in
other areas to help forecast the extent of damage and the
cost of rehabilitation, to clean the soil environment. The
oil trenches are also reported to pollute the water
resources in shallow water table areas, and therefore,
this calls for an immediate action plan for their
rehabilitation, or atleast a plan to a regular monitoring
of oil contamination to surrounding areas and the in the
prevailing plant community.
Free-Phase
Soil Limits for Volatile Organic Compounds: Evaluation of
Sensitive Parameters, Site-Specific Variables and
Applicability for Establishing Cleanup Goals
Eric M.
Cherry, Hull & Associates, Inc.
Free-phase
limits, or soil saturation limits, have been used by
Federal and state regulatory agencies to establish
preliminary remediation goals (PRGs) or as actual site
cleanup standards for volatile organic compounds (VOCs).
The free-phase limit is defined as the concentration in
soil where all available compartments (i.e. soil organic
carbon, soil moisture and soil vapor) have reached the
saturation limit and a nonaqueous phase liquid is present
in the soil. The fundamental relationships of these
properties to the free-phase limit is provided by the 1996
USEPA Soil Screening Guidance Document.
A
sensitivity analysis has been conducted for a series of
chlorinated and aromatic VOCs under different soil
conditions to determine which variables have the most
significant effect on the free-phase limit. VOCs were
selected on the basis of their range of solubility, vapor
pressure, Henry’s Law constant (H) and organic carbon
partition coefficient (Koc). For individual VOCs, the
fraction organic carbon (foc) content was the most
sensitive variable, resulting in variations of up to 2.6
orders of magnitude in the free-phase limit over the
anticipated range of foc in native soils. The degree of
water saturation is a sensitive parameter at foc values
less than 0.01, with free-phase limits varying by a 5 to
40% over normal ranges in soil moisture content. The
overall behavior of each VOC was dependent upon the
variation of both specific physiochemical properties and
soil properties. Further uncertainty may be introduced by
variations in Koc that are dependent upon the type of
organic matter present in the soil.
This
assessment indicates that default free-phase limits should
not be adopted for sites as PRGs or remedial standards
without a thorough evaluation of the variation in
geotechnical properties and organic carbon content of
soils, because the default PRGs can substantially
underestimate the site-specific free-phase limits.
Expedited
Site Assessment at a Large Naval Fuel Terminal
Robert W. Magee, Atlantic Division, NAVFAC. George
Steffen and Peter Lang, Navy Public Works Center Norfolk
Implementing expedited site assessment procedures at
this site saved money, compressed reaction time, and
influenced contaminant migration. Craney Island Naval
Depot, Portsmouth, Virginia is a large fuel terminal with
the mission to supply fuel to the Navy's Atlantic Fleet.
The terminal offered excellent conditions for implementing
expedited site assessment procedures - established site
model and understood contaminant conditions. Expedited
site assessment procedures afforded quick, concentrated
action - release identification to interim solution in
less than 1 year.
In May 2000, a petroleum release was identified in a
storm water outfall near a fuel tank farm. A site
characterization using the Navy's Site Characterization
Analysis and Penetrometer System (SCAPS) was performed in
May 2000. SCAPS uses laser-induced fluorescence (LIF)
technology to detect petroleum contamination and Cone
Penetrometer Test (CPT) data to provide soil
classification profiles. Data interpretation provided the
vertical extent of contamination, identification of the
optimum intervals for sampling, and the placement of
monitoring and recovery wells, including their respective
screen intervals. Field decisions allowed contaminate
trends to decide push locations. A non-aqueous free
petroleum product plume covering 3.5 acres and up to
8-feet thick was detailed. Soil and groundwater samples
taken confirmed and established the quantitative
significance of the LIF data. Risk assessment and
risk-based endpoints were established. An aggressive
remedial approach for collecting free product off the
water table, preventing further migration of free product,
and stopping free-product discharge to surface waters was
decided. The tank was drained and taken out of service in
May 2000; demolished in November 2000; stop gap interim
action taken in January 2001; and corrective action plan
submitted in February 2001.
An
Evaluation of Soil Background Concentrations in South
Boston
Martha L. Zirbel, Metcalf & Eddy, Inc., John R.
Nelson, Mark E. Radville, and William Levy, Massachusetts
Water Resources Authority
According to the Massachusetts Contingency Plan, oil
and hazardous materials that are present at or below
background levels are considered, by definition, to pose
no significant risk. Further, disposal sites at which all
oil and hazardous materials are reduced to levels at or
below background are eligible for a Class A-1 Response
Action Outcome. In addition to geologic conditions, the
MCP definition of background may include contaminants
attributable to anthropogenic sources, including coal ash
and wood ash found in fill ("urban fill").
Therefore, quantifying background concentrations is
important for assessing disposal sites in areas where it
is suspected that either geologic or anthropogenic impacts
have resulted in elevated concentrations of chemicals of
potential concern. Anecdotal evidence suggests that
statewide background levels for chemicals that have been
published by DEP and used to develop MCP Method 1 Risk
Characterization standards may underestimate background
concentrations of metals and/or organics in areas of
coastal urban fill and where clay soils predominate. On
behalf of MWRA, M&E conducted an environmental
investigation prior to the design of the North Dorchester
Bay and Reserved Channel Consolidation Conduits and
Reserved Channel CSO Facility in South Boston. Over 200
soil samples were collected and analyzed from both marine
clay deposits and coastal urban fill. Many sample
locations were unbiased, i.e., they were not targeted at
known releases of oil or hazardous materials. The authors
use this database to provide an evaluation of various
metals and organic chemicals in marine clay and urban
fill, and present distributions, ranges, and estimates of
the mean, using methods suggested by EPA and DEP guidance.
The results are compared to soil background levels
published by DEP.
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