. 
DIVISION OF
ENVIRONMENTAL PROTECTION
TDD <BO»> 777-6413
GOVERNMENT OF THE VIRGIN ISLANDS OF THE UNITED STATES
———0———
DEPARTMENT OF PLANNING AND NATURAL RESOURCES
NISKY SHOPPING CENTER
SUITE 45
CHARLOTTE AMALIE, ST. THOMAS, V.I. OO8O2
Express Mail
Return Receipt Requested
November 30, 1994
Caroline Kwan
USEPA, Superfund Division
New York/Caribbean Branch
Region II
26 Federal Plaza
Jacob Javits Building
New York, NY 10278
Dear Ms. Kwan:
Enclosed are the Virgin Islands Department of Planning and Natural
Resources (DPNR) comments on the October 1994 Draft Remedial
Investigation (RI) report for the Tutu Wells Superfund Site in St.
Thomas, USVI. 
These comments should be addressed by the
Potentially Responsible Parties (PRPs) prior to the f inalization of
the RI and the preparation of the Draft Feasibility Study.
If you have any questions regarding this matter, please contact Mr.
David Rosoff or Mr. Adrian Schottroff of my staff at (809) 774-
3320.
Sincerely yours,,
L/ , * A
Benjamin I. Nazario, Director
Enclosure
T'U I" 006 
054",
*64620*
64620
DPNR COMMENTS ON THE DRAFT REMEDIAL INVESTIGATION FOR THE TUTU
WBLLPIBLD SUPERFUND SITE IN ST. THOMAS, USVI
General Comments:
Data presentation and analysis:
The discussions of work performed by "other consultants"
throughout the document is misleading because Geraghty & Miller
Inc. has chosen to selectively include and exclude data from
various sampling events from the report. As a result, the entire
representation of the data and the assumptions and conclusions
drawn from the data is biased and potentially incorrect. The RI
report must include all available data collected at the site.
The following represents instances where data has been excluded
to the detriment of the report:
Overall site:
The exclusion of the majority of COM (1988-1989) generated soil
data in the discussion and on the figures for each property
because the locations of the sampling could not be pinpointed is
unacceptable. The exclusion of this and other soil data severely
hampers both the credibility and the accuracy of this report.
The sampling locations must be obtained and the data must be
added to the report.
Esso Service Station:
A November 1987 multi-site soil vapor investigation conducted by
Geosciences Consultants, Ltd. for Texaco Caribbean, inc.
A soil sampling and underground storage tank removal conducted by
Soil Tech and reported in January 1990.
Discussion of the January 1992 soil gas survey conducted by
Target Environmental Services, Inc. at Four Winds Shopping
Center, especially in the northern portion of the Tutu Esso
station.
An April 1994 ground-water sampling event conducted by Blasland
Bouck and Lee, Inc.
Four Winds Plaza:
Water sampling of the 4 inch PVC pipe located under the western
side of Four Winds in November 1993 by Caribbean Hydrotech.
TUT OO6 0548
November 30, 1994
VIDPNR's Tutu RI Comments
Soil sampling of an underground vault within Cost-U-Less in
December 1993 by Caribbean Hydrotech.
An expanded Gore-Serber study performed in July 1994 by ENSR
under the Four Winds building.
0'Henry Dry Cleaners:
Slug tests performed on O1Henry wells.
The need for a supplemental hydrogeologic investigation:
Currently, the existing hydrogeologic database used for the
understanding of the hydrodynamics of the Tutu valley aquifer
system is lacking in certain areas. As a result, the RI does not
adequately address the hydrogeology of the entire site and
provides a stunted understanding of the hydrodynamics of the
contaminant plume.
Ground-water elevation data for both the shallow and deep aquifer
zones is severely lacking in the southern part of the site.
Ground-water elevation data for the KFC-l, KFC-2, Harthman-
Wilfred, Harthman-Bakery, CHT-5, EA Corp. #1, EA Corp. #2, EA
Corp. #3, EA Corp. #4, Rodriguez, New Gassett, REMW-2, REMW-3,
REMW-4, LaPlace, MW-21D, MW-22D, Mathias, Delegarde and Smith
supply wells and the Fort Mylner and Versailles wells should be
collected. In addition, monitoring wells should be installed in
the lots southwest of O1Henry Cleaners and in the pasture
southeast of the Fort Mylner Shopping Center in the vicinity of
"Fort Mylner." This information is critical for understanding
the nature and direction of ground-water flow to the south.
The extent of the plume to the south, southeast and southwest as
well as north has not been determined adequately. Alternate
contaminant sources could be located north of the Curriculum
Center and the Virgin Islands Housing Authority (VIHA) and in the
area of Kentucky Fried Chicken (KFC) to the south. 
The
installation of additional monitoring wells or the institution of
a temporary well point program is necessary at the site prior to
the completion of the Remedial Design to define these areas.
At a minimum, the investigation of the Tutu aquifer needs to be
extended to include the known and suspected gasoline
contamination emanating from the vicinity of KFC, formally Home
Petroleum, and from Rodriguez Esso. Existing ground water data
show MTBE as well as chlorinated hydrocarbon contamination
reaching at least as far southeast as the Delegarde well. It is
"UT OO6 O549
November 30, 1994
VIDPNR's Tutu RI Comments
not clear, given the lack of information between the Delegarde
well and the Fort Mylner mall, whether this contamination is
coming solely from the sites to the north (Esso, O'Henry, etc.)
or is also coming from Fort Mylner and Rodriguez, or whether the
contamination is being combined from both sites.
The ground water component associated with Turpentine Run, i.e.
that portion of ground water flow that is coincident with surface
topography and the stream bed of Turpentine Run, has not been
investigated to any extent. Ground water levels taken during
1990 investigation of the former Home Petroleum station (present
KFC location) indicate a shallow ground water gradient in the
direction of Turpentine Run. It is very likely that there is a
co-mingling of contamination plumes in this vicinity as it is
probable that ground water flow is structurally as well as
topographically controlled. This possibility must be considered
in the Remedial Design phase of the project.
Ground-water contamination should also be investigated further
along the eastern portion of the plume to define its easternmost
extent, preferably in the area of Tillet Gardens.
Pump test:
A larger scale pump test should be performed which monitors a
wider array of wells in differing vertical and horizontal
locations. This pump test will provide greater coverage, more
extensive site wide aquifer characteristics. This information is
needed especially west and east of Route 38 in the center of the
site as it is now defined. 
The information is needed for
ground-water flow modeling that must be completed during the
Remedial Design.
Soil contamination discussion:
The methodology used to discuss source soil contamination and
determine the origin of ground-water contamination is unclear and
implemented inconsistently. It is DPNR's position that if the
contaminant was historically used, stored or disposed of at a
facility then that facility is a potential source property. This
is regardless of the presence or absence of a contaminated soil
sample on the property. DPNR feels, in the case of many
properties, that insufficient soil samples have been collected
and analyzed to adequately determine if that property is
unquestionably not a source.
CO 6
November 30, 1994
VIDPNR's Tutu RI Comments
DPNR is particularly in disagreement with the assumptions that
Geraghty & Miller used in the soils discussion. These assumptions
have severely biased the interpretation of the soil data
presented in the RI report.
The following assumptions listed in Section 5.1 are disputed:
Values of volatile organic compounds (VOCs) in soil samples that
are less than 10 parts per billion (ppb) do not indicate a
release or source of VOCs. Instead these values are attributable
to ground-water contamination: This assumption may be valid in
some instances but almost surely not in all instances. It
applies an arbitrary concentration instead of a risk based level
to discuss or dismiss an area's potential for remediation. A
more valid concentration should be generated through ground-water
fate and transport modeling for each contaminant to determine
which areas should be recognized as sources requiring potential
remediation. If a soil sample displays a low level concentration
of VOCs then it may indicate a nearby source and additional
investigation is necessary to confirm the absence of nearby
contamination.
If no soil sampling was completed at a property but soil gas
sampling was negative then the property has not been impacted by
contamination: No property that is considered a potential source
can be declared free of impact unless soil sampling is used in
combination with soil gas. A soil gas survey alone is not
sufficient to rule out a property as a source.
The determination of BNA impact on soils is not based on
concentration alone and must be based on other factors: The
description of these factors, how they weighted and how the
determination of impact is made must be clarified.
If contaminants are found only in an excavated soil pile then the
property is not considered impacted by that contaminant: If an
excavated soil pile is contaminated then it has likely originated
from the property it presently is located on. This indicates
that the property has contained contaminated in-situ soils at one
time. At the least, extensive sampling should take place to
determine if the in-situ soils in the area of the waste pile have
not been impacted.
If isolated samples are contaminated but surrounded by samples
that are non-detect then soil on the property has not been
impacted by contamination: This assumption is too general to be
implemented across the entire site. The spatial distribution of
the surrounding samples and the concentration of the contaminated
TUT
OO6 
O5S.1
November 30, 1994
VIDPNR's Tutu RI Comments
sample must determine whether additional sampling is needed, the
property is a source area or the soil has not been impacted.
For metals and other inorganics, impact to soil for a particular
compound was considered if the analytical result exceeded the
background value by at least one order of magnitude: 
This
assumption places an arbitrary distinction on what is considered
an inorganic impact to soil. A risk generated concentration or a
statistically modeled (based on background samples) cleanup goal
should be used for each inorganic instead of this meaningless
designation.
Adequacy of soils data:
Based on the presentation in the draft RI report, the available
soils data is sporadic and was collected in a haphazard
uncoordinated manner. Currently, there may not be adequate soils
data for the entire site as a whole to prepare a Record of
Decision (ROD). DPNR recommends the implementation of a
supplemental Remedial Investigation for soils. This
investigation would include expanded sampling at the Curriculum
Center, VIHA, Tillet Gardens, Antilles Auto, Esso Service
Station, Western Auto, Rodriguez Service Station and Kentucky
Fried Chicken. Sampling should include the necessary parameters
to address the contaminants of concern and to undertake a fate
and transport modeling effort. This data would be used in
concert with previously collected data to determine cleanup goals
for soils based on future impact to ground water through fate and
transport modeling. This modeling may have to be supplemented
with site-specific soil leaching studies (column studies) to
determine realistic partition coefficients for contaminants in
this type of aquifer. This supplemental field and modeling work
could be completed as a focused RI under a separate operable unit
(Operable Unit II with Operable Unit I being ground-water
remediation) or during the Remedial Design of a ROD with a
generalized remedy.
Specific Comments:
Page 1-9, Paragraph l: 
Site inspections must occur at all
facilities that may represent a potential source of contamination
to soil and ground water at the Tutu site. It is not acceptable
to not conduct site inspections on key properties because
"difficulties were encountered obtaining access." Furthermore,
it is unclear upon what basis Geraghty & Miller Inc. determined
that enough information was already available for each property
TUT OO6 0552
November 30, 1994
VIDPNR's Tutu RI Comments
to preclude a site inspection. Sites that were not inspected
still represent a potential source of contamination.
Page 2-11, Paragraph 3: Data collected during the supply well
sampling should be presented in an appendix to the RI report.
DPNR recommends that annual supply well sampling be continued
through the Remedial Design phase of the project to monitor
ground-water quality and plume dynamics. DPNR is not satisfied
that the ground water in the supply wells has been adequately
characterized. The recent discovery of contamination in the
Delegarde well is an example of the lack of adequate plume
characterization.
Page 3-14, Paragraph 3: All materials to be disposed of at the
Bovoni Landfill in St. Thomas must be sampled for all RCRA
characteristics, TCL organics, TAL metals and TPH and must be
approved for disposal by DPNR prior to shipment off-site.
Page 3-15, Paragraph 4: All the results from the various soil
gas studies should be summarized and presented in the RI report.
Page 3-20, Paragraph 2: EPA Standard Operating Procedures (SOPs)
for well development require stability of pH, temperature,
conductivity and turbidity within 10% following each of at least
3-5 purged well volumes prior to completion of development. It
is unclear what is meant by "well development was continued until
the discharged water was relatively sediment free." Apparently,
wells may not have been appropriately developed prior to sampling
by Geraghty & Miller.
Page 3-22, Paragraph 2: Well sampling data from the first phase
of the RI should be summarized in this RI report and related to
the Phase II sampling round.
Page 4-2, Paragraph 2: 
The RI report fails to present a
complete inventory of potential contaminant sources in the Tutu
valley. For example, KFC (formerly Home Petroleum) is not
adequately characterized or discussed. The report also fails to
thoroughly identify previous land use and current industrial use
in the valley.
Page 4-13, Section 4.5.3. and Page 4-20, Section 4.6.2.: 
The
orientation of turpentine run basin and its relationship to the
hydrodynamics of the site should be expanded and related to the
fracture analysis. Additional discussion is needed to clarify
the relationship between ground-water flow patterns and the
orientation of the major fracture lineaments shown in Figure 4-8.
DPNR considers the deep and shallow aquifer zones as part of an
TUT OO6 O553
November 30, 1994
VIDPNR's Tutu RI Comments
interconnected heterogeneous water table aquifer. In some areas
this connection is not in a highly transmissive zone. The RI
report is unclear regarding the relationship between the bedrock
and alluvial water bearing zones.
Page 4-22, Paragraph 2: Shallow ground-water flow appears to
shift to the southwest in the southern portion of the site.
However, a dearth of ground-water elevation data in the area does
not allow for the accurate prediction of ground-water flow
patterns.
Page 4-23, Paragraph 2: Water level data from existing wells
which is needed to describe the ground-water flow in this area is
absent in the southern portion of the site along and to the east
and west of route 38.
Page 4-35, Section 4.6.3.: 
This section is in need of
substantial expansion to include more detail regarding the
hydrodynamics of the site. Figures should created and referenced
to illustrate the site hydrogeologic model. Specific information
such as flow rates and flow direction should be discussed. This
model should provide the framework for understanding contaminant
distribution at the site and provide a basis for remedy analysis.
Section 5.1.1. and Figure 5-1 (V.I. Housing Authority): The only
soil samples shown in the RI are from drilling activities of MW-
13 and MW-13D. Soil sampling needs to be done in the vicinity of
soil gas survey sites SGS-10 and SGS-13 to confirm/check elevated
BTEX readings reported during that survey. Additionally,
chlorinated compounds were found in waste oil samples OIL 10, OIL
02 and OIL 891718. Soils on site should be analyzed for those
chlorinated compounds (1,1,1 TCA, PCE, 1,1 DCE).
Soil gas sampling was conducted in the area of the former UST on
the property. Because the soil gas reveal no contamination, the
area is considered not impacted by VOCs based on the criteria for
soil impact. As stated earlier this criteria is grossly flawed
and unacceptable for final determinations such as this. Soil gas
must be followed up by extensive confirmatory sampling in the
area of the former UST. Furthermore, based on Figure 5-1, only
two soil gas samples were collected within forty feet of either
drum storage area. This coverage is inadequate considering that
chlorinated and nonchlorinated VOCs were detected in the drums
stored at the northwest corner of the building.
Section 5.1.2., Figure 2 (LAGA facility/DOE Curriculum Center):
Soil sampling needs to be done to confirm/check the soil gas
survey that was used at the site for a screening tool. Existing
TUT OO6 0554
November 30, 1994
VIDPNR's Tutu RI Comments
soils data for the LAGA site do not show extremely elevated
contamination levels although significant ground-water
contamination exists at MW-16, MW-1 and MW-1D. Existing soils
data were not taken from the "hot spots" inferred by the soil gas
survey. The northern (on the north side of the fence), eastern
(near the paint disposal area) and western portions of the
building should be targeted for sampling.
As stated earlier, the use of following statement within this
report is not acceptable: "data were not included for some
sampling locations because samples from these locations were
analyzed only for metals or the exact sampling locations (for
example, those collected by CDM) were not known."
The high values of Total Organic Carbon (TOO with no detects
(nd) for non-BTEX VOCs, BTEX and BNA compounds, and TPH for
several of the samples (SS-7, SS-8, SS-10, SS-11) should be
explained for these types of soils (low organic content).
Section 5.1.3. and Figure 5-3 (Ramsay Motors): A vertical
distribution of soil contamination for MW-15 and MW-17 should be
provided.
The following statement in Paragraph l on Page 5-11 and all
statements similar to it throughout the document must be removed:
"As explained in the assumptions, the occurrence of chlorinated
VOCs at concentrations below 10 ppb is likely the result of
volatilization from ground water." If PCE and other VOCs in
soils at less than 10 ppb the result of ground-water
contamination, then why are PCE and other VOCs not found at low
levels site wide.
On Page 5-11, Paragraph 4, the report states that there is no
evidence that Ramsay Motors is a source of chlorinated VOCs.
However, drum sampling at the site identified PCE and TCA present
in waste oil on the property. It is possible that these
contaminants were also present in the waste oil UST. DPNR is not
comfortable ruling out Ramsay Motors as a potential source of
Chlorinated VOCs without additional confirmatory sampling near
the UST.
Section 5.1.4. and Figure 5-4 (Antilles Auto Parts): Soil
samples need to be taken elsewhere on the property other than at
the waste oil tank (B-5) to determine whether contamination
exists more widely across the property. CDM sampling locations
must be determined and added to the discussion.
TUT OO6 O555
November 30, 1994
VIDPNR's Tutu RI Comments
Section 5.1.5. and Figure 5-5 (Tutu Texaco): CDM and Weston
sampling locations must be determined and the data must be added
to the report.
The following statement on Page 5-14, Paragraph l is misleading:
"the drum storage area is paved with concrete and the presence of
a contaminant in a drum does not by itself indicate that an
impact to soil quality has occurred." Although the statement is
true it implies that the drums and the drum pad area do not
represent a potential source of contamination. Considering that
staining has be seen on the concrete and the area is not entirely
paved, it is likely that a release to the subsurface has
occurred. As a result, DPNR feels that this assumption is
premature.
The statement on Page 5-15, Paragraph l that "based on the
criteria developed, there is no evidence that the Texaco service
Station has soil impacted by chlorinated VOCs and or BNAs is
inconsistent with the presented strategy and incorrect based on
the available data. Soil samples at Texaco reveal concentrations
of BNAs between 130 and 170 ppb. Other properties such as Tillet
Gardens and Ramsay Motors have similar concentrations of BNAs in
soils and are labeled as being "impacted" by BNAs. It is
inconsistent to not include Texaco as an BNA impacted property.
Furthermore, the exclusion of the following data has skewed the
conclusions regarding chlorinated VOCs at Texaco:
NUS sampling in 1989 detected PCE at 160 ppb in a soil pile on
the site.
NUS soil gas survey in 1987 indicated PCE in the unsaturated zone
beneath the property (NUS, 1991)
Soil sample collected by CDM in 1988 contained DCE (10 ppb)
In June 1989, CDM found TCE (39 ppb) and PCE (160 ppb) in a soil
storage drum sample
In August 1987 CDM found 2,400 ppb of 1,1,1 TCA in an oil water
separator
Based upon this data the conclusion that the Texaco property is
not a potential source of chlorinated VOCs is insupportable.
Section 5.1.6. and Figure 5-6 (Tillet Gardens): No sampling has
been done to date in the vicinity of the Art Gallery or Mike's
Paints. Ground-water data show an increase in concentrations of
chlorinated compounds in the well at Tillet Gardens which might
TUT OO6 O556
November 30, 1994
viDPNR's Tutu RI Comments
indicate a source in that area. The site requires further
detailed investigation - possibly a soil gas screening effort and
soil sampling to check high soil gas values.
Section 5.1.7. and Figure 5-7 (Four Winds Plaza): Sampling
values shown are not at consistent depths or depth ranges
rendering horizontal and vertical interpretation impossible.
These values must be presented:
e.g. well/sample 
sample range included
CHT-3 
29.0-29.5'
CHT-2 
10'
MW-10 
2-4'
MW-10D 
0-2'
MW-18 
12-14'
MW-9 
0-2
The criteria for impacted soils is applied throughout the
discussion of Four Winds. PCE and other VOCs in soil are related
to ground-water contamination. The assumptions used to make this
determination must be re-evaluated.
No discussion of metals' sampling is provided for Four Winds.
Section 5.1.8. and Figures 5-8 and 5-9 (Western Auto): High TPH
values are evident in the waste oil tank pit. As a result, there
needs to be further investigation under the slab - i.e. under
Western Auto store and the Quality Drug Store to determine down-
gradient migration of TPH. The elevated concentrations of TPH
may mask the presence of chlorinated VOCs within the oil plume
beneath Western Auto. The downgradient extent of this component
in soils has not been adequately delineated in this area.
The following statement on Page 5-22, Paragraph 5 is premature
and should be revaluated: "Chlorinated VOCs have apparently not
impacted soil based on the criteria defined."
The assumption that one detection of PCE in soil sampling is not
indicative of impact to soil is flawed by a lack of adequate
sampling. The adjacent samples to this detection all had
extremely elevated detection limits potentially masking any lower
level contamination. Because PCE was detected in soil, this area
must be further investigated as a potential source.
The three samples collected by ENSR in December 1993 to evaluate
the four-inch waste pipe must be shown on the figure and
10
TUT OO6 0557
November 30, 1994
VIDPNR's Tutu RI Comments
discussed.
Section 5.1.9. and Figure 5-10 (Esso): 21 CDM samples are
excluded from the discussion and the figure because locations
were unknown to Geraghty & Miller. This is unacceptable an
severely skews the interpretation of the soils from this
property.
The following detailed information from the CDM study have been
omitted from this section:
Measurements of 58,000 ppb of 1,1,1 TCA and 110,000 ppb of PCE in
an oil/water separator in August 1987
Measurements of 100,000 ppb of 1,1,1 TCA and 65,000 ppb of PCE in
an oil/water separator in September 1988
Measurements of 42,000 ppb of 1,1,1 TCA and 91,000 ppb of PCE in
an oil/water separator in July 1989
Sampling at SS-8 location should continue below the 7.0 foot
level to determine vertical extent of chlorinated contamination.
No soil values were reported for CHT-7D and MW-9S. Soil data
should be available for these wells during their installation.
Section 5.1.12.2.: Ramsay Motors, and Texaco should be included
as properties that have been impacted by chlorinated VOCs.
Page 5-34, paragraph 4: Elevated BTEX in the vicinity of RFC
indicates that the BTEX plume has not been defined in this area.
Because of the lack of information regarding the ground-water
flow in this area it is imperative that this portion of the plume
be investigated further.
Page 5-35, Paragraph 2: MTBE has been found at substantial
distances from the suspected source areas (e.g. the Delegarde
well). No other source has been shown to exist in the south
eastern portion of the site where detections have occurred. The
nature and extent of this MTBE plume must be further investigated
and discussed because it provides important information on
ground-water flow and transport. MTBE should not be ignored just
because there is no Federal drinking water MCL.
Section 5.2.1.3.1.: The northern extent of the plume has not yet
been adequately delineated. No wells north of VIHA-1 have been
sampled and VIHA-1 contained chlorinated solvents. Sources areas
in the northern part of the Tutu valley should be investigated.
11
TUT O06 0558
November 30, 1994
VIDPNR's Tutu RI Comments
Section 5.2.2.: 
All sites should be evaluated for the
presence of DNAPL, not just 0'Henry and the Curriculum Center.
For example, the Esso Service Station has had detections of PCE
in excess of 1,000 ppb in the soil and, as a result, should be
discussed here.
Section 5.2.3.: 
The report should indicate that DNAPLs may be
present at the site, but the probability can only be assessed
through a more detailed analysis that includes a study of soil
characteristics (TOC, grain size, etc.), ground-water chemistry
(pH, temperature, etc.) and fate and transport modeling. Such a
study should occur during the Remedial Design phase of the
project. No attempt has been made to establish the oxidation-
reduction conditions in the aquifer. This information is
necessary to determine the appropriate breakdown pathway of PCE
for fate and transport modeling.
Section: 5.2.6.: 
Page 5-47, Paragraph 2: Chlorinated VOC
contamination was high in the soil gas survey conducted at the
Curriculum Center. Chlorinated VOC contamination was not
conclusive as a significant source from the soil sampling data,
which predates the soil gas survey. Detailed soil sampling to
confirm the soil gas survey results needs to be done at the site.
The statement that "the Esso Tutu Service Station does not appear
to have contributed chlorinated VOCs to the groundwater" is not
convincing since the highest values of chlorinated solvents was
found in soils at the Esso station - with sampling to at least 7
feet below surface.
Section 5.2.6.1.2.: This section omits any responsibility of Esso
as a source for VOCs. The contouring is too coarse to indicate
some important trends. Overall, there is a marked decrease in
chlorinated contamination values downgradient from the Curriculum
Center, in the vicinity of Tutu Texaco, then the chlorinated
values increase in the Tillett area to as high as 585 ppb in the
Tillett well. The values decrease slightly downgradient from
Tillet to the 130 to 200 ppb range in the vicinity of Esso.
These values remain relatively consistent for about 300 feet
south of the station before falling off below the 100 ppb
threshold. This constancy of values of chlorinated VOCs under
and in the vicinity of ESSO does not preclude the soils under
ESSO from being a source. The soils could well be a lower-level
source to the ground water, keeping the chlorinated values
constant, rather than allowing the concentrations to decrease
steadily from the source.
12
TUT 006 0559
November 30, 1994
VIDPNR's Tutu RI Comments
The statement made throughout the document that there are two
distinct plumes of chlorinated VOCs in ground water is
misleading. The RI has not adequately determined all the
potential chlorinated VOC sources where distinct plumes may be
emanating from and has not adequately demonstrated a distinction
between the areas that are mapped. Esso and Texaco are two
potential source areas that have not been adequately addressed in
this section.
Page 5-46, Paragraphs l & 2: Although two "separate and distinct
BTEX plumes" are indicated on the map, and the distribution of
BTEX downgradient from Esso seems limited, the MTBE values
effectively smear the two plumes together. Further, and more
important, MTBE values extend downgradient from the vicinity of
the Esso station all the way to the Delegarde well. MTBE values
are present in MW-19, DW-2, Eglin-I, Eglin-lII, Steel, LaPlace,
Smith, Delegarde and KFC-1. Limiting discussion to the BTEX
plumes only does not adequately describe the extent of gasoline
contamination in this aquifer.
Page 5-46, Paragraphs 3 & 4: BTEX contamination was reported
during the 1990 excavation of USTs at the former Home Petroleum
(RFC) site. This extent of this contamination needs to be
evaluated further, but there is no clear evidence to show that
the Home Petroleum contamination is the source for the MTBE in
the vicinity of the Delegarde, Smith and LaPlace wells.
Section 6: A quantitative fate and transport modelling study is
necessary to determine risk to ground-water based remediation
goals for soil.
13
TUT OO6 O56O
Summary of Soil Cleanup Goals/Screening Levels for Tutu-Ramsay
Site (ug/kg)
Chemical
BTEX Compounds
Benzene
Toluene
Ethylbenzene
Xylenes
Chlorinated VOCs
Tetrachloroethane
cis-1,2 Dichloroethene
trans-1,2
Dichloroethene
Trichloroethene
Semi-VOCs
Naphthalene
Inorganics
Arsenic
NYS TAGM (foc+1%)
(DAF=100)
(Note 1)
60
1,500
5,500
1,200
1,400
300
700
13,000
7,500 or Site Bkgd.*
Notes
New York State (NYS) Technical and Administrative Guidance
Memorandum, NYS Dept. of Environmental Conservation, Division
of Hazardous waste Remediation, HWR-94-4046, Jan. 24, 1994
(Revised). The given Recommended Soil Cleanup Objectives
assume foc=l% and Dilution Attenuation Factor (DAF) [or simply
Dilution Factor]=100. (The assumptions for foe and DAF are
not applicable to Arsenic.) Given levels are same as for
groundwater protection.
* Use Site Background if available.
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