Comments to the Conceptual Sampling
Plan for Lemon Lane Site
by the Environmental Compliance Organization
May, 1995
The Environmental Compliance Organization (ECO), in its capacity as technical
advisor to Citizens Opposed to PCB Ash in Monroe County (COPA), has reviewed
a memorandum from Richard Flores of Earth Tech to Dan Hopkins of the U.S.
Environmental Protection Agency (EPA), dated April 11, 1995. The subject
of the reviewed memorandum is the conceptual sampling plan for the Lemon
Lane site. After reviewing the memo and accompanying documents ECO offers
the following comments:
In general, this sampling plan repeats the errors and omissions that
have seriously impaired the utility of past sampling efforts at the Bloomington
sites.. Of note is the failure to use this sampling event as an opportunity
to adequately and definitively delineate the extent of contamination at
the Lemon Lane site. Comprehensive scoping of the exact locations and concentrations
of contamination at a site is routine to all remedial investigations, pre-requisite
to designing and/or implementing cleanup, and is long overdue for this,
and all of the Bloomington sites.
Specifically we strongly recommend that the site and near off-site locations
be gridded, and an adequate grid selection and sampling procedure be employed.
A wealth of anecdotal evidence suggest that the waste and contaminants of
concern may lie substantially outside the existing fence line, and it is
imperative that these areas be thoroughly investigated.
Of additional concern is the proposed field measurement of PCBs as a
threshold for further laboratory testing. While field screening can prove
an economical and rationale way of limiting samples sent on for costly analyses,
we cannot concur with the selected threshold of 400 ppm. PCB contamination
at 400 ppm is well above all regulatory action levels, and also exceeds
levels generally considered to negatively impact both human health and the
environment. ECO is uncomfortable with the lack of detail concerning who
will actually be performing the field tests, and more importantly the crucial
review and determination of results. Additionally, given the uncertainties
and inaccuracies inherent to all field screening methodologies, it would
seem more prudent to rely on mobile laboratory analytics for accurate, but
time and cost efficient screening methods.
Our final and chief concern is with the parameters selected for analysis
on samples that do pass field screening thresholds. Although it is widely
acknowledged that the toxic dioxin and furan families of chemicals are very
frequently contaminants of PCBs, are especially likely to occur where there
has been burning activity, and despite a well documented history of requests
to EPA for inclusive and comprehensive dioxin/furan analyses, EPA apparently
intends to under utilize/omit these crucial tests yet again.
This is simply unacceptable. Current information generated by EPA indicates
that dioxins and furans are magnitudes of order more toxic than PCBs, and
potentially more threatening to human health from both cancer and non-cancer
effects than previously reported. The citizens of Bloomington are absolutely
entitled to information on the dioxin /furan status of this, and all other
PCB sites in the area so that they may finally come to informed conclusions
regarding potential risks posed by these facilities. Clearly, no remedial
solutions can be contemplated, much less commenced until the presence or
absence of these critical contaminants is adequately determined.
Toward that end, ECO urges that all samples submitted for analyses be
tested for dioxin/furan utilizing the ultra-sensitive laboratory method
developed by, and available from Triangle Laboratories, located in the EPA
complex at Research Triangle Park, North Carolina. This extremely sensitive
testing is capable of detecting dioxins and furans in the parts per quadrillion
concentrations that represent the regulatory thresholds for these extremely
toxic substances.
Finally, adequate surface and groundwater samples from Lemon Lane and
adjacent areas must be collected and subjected to this same high level analysis,
so that critical determinations about potable and recreational waters can
at long last be made on some real, scientific basis.
ECO firmly believes that all the foregoing comments must be considered
and incorporated into the planned sampling at Lemon Lane in order to produce
the quantity and quality of information that will further the eventual remediation
of this site. Our staff is available, upon request to further discuss these,
or any other issues related to the Bloomington PCB sites.
Additional Commentary
Melissa Valentin of MVA Consulting, Inc. has also reviewed the conceptual
plan and provided ECO with a memorandum detailing questions and concerns
regarding the planned field event. The information contained in that memorandum
is provided here in its entirety.
Objectives
The conceptual sampling plan must include precise definition of the sampling
objectives and an explanation of how the proposed sampling will achieve
those objectives.
Based on the sampling and analyses proposed, the objectives appear to
be:
- Determine whether PCB concentrations in areas of suspected capacitor
disposal exceed 400 ppm using field test kits,
- Determine whether PCB concentrations above the sinkhole centers exceed
400 ppm using field test kits,
- Submit samples having more than 400 ppm PCBs for the following laboratory
analyses, in this sequence, until sample is depleted: PCBs, pesticides,
VOC, SVOCs, PPMs, DFs.
- Based on the work proposed, the objectives are NOT to:
- Identity all hot spots
- Delineate areas requiring excavation/treatment and areas that can be
safely capped in place
- Collect data to permit selection of appropriate treatment/disposal
options,
- Collect data to permit calculation of risk to human health and the
environment under current conditions and post-remediation conditions,
- Validate the precision and accuracy of the soil test kits when used
on landfill material
Appropriateness of Objectives
Not only does this sampling program fail to achieve the broader and more
important goal of site characterization, it is an ineffective attempt to
define PCB hot spots. If the objective is limited to finding evidence, any
evidence, of extremely high PCB contamination, this effort may fail because
too few borings are proposed: only 11 to 17 borings will be placed in presumed
capacitor disposal areas covering 2 to 5 acres. Specific recommendations
for changes to the sampling plan are presented below.
Contingency for Installing
Additional Borings
The sampling procedures and flow chart must be revised to permit the
installation of additional borings if none of the original borings encounter
hot spots. Funding for these additional borings will be available because
currently, none of the samples containing less than 400 ppm PCBs will be
submitted for extensive laboratory analyses.
Definition of PCB Hop Spot, Use
of Clear and Accurate Terminology
PCB Hot Spot must be precisely defined. The term hot spot implies discrete
areas of contamination separated by clean areas. The definition of PCB "contamination"
requiring remediation is typically from 1 to 25 ppm for surface soils and
1 to 50 ppm for soils at depth, depending on the potential for contact with
the waste or PCB migration. If the areas of contamination are not discrete,
use of the term hot spot is inappropriate. The PCB concentration proposed
for hot spot is apparently well above 400 ppm, which is at least an order
of magnitude too high. More descriptive terms must be used in this situation,
and instead of reliance on the vague but attractive phrase "hot spot",
I suggest that PCB concentration ranges be used. For example, this is a
sampling effort aimed to identify zones of PCBs greater than 400 ppm and
areas containing less than 400 ppm will be ignored, for now.
Further, hot spot delineation requires precise definition of where a
hot spot begins and ends, including assumptions for interpreting between
sampling points. For example, if two borings encounter PCB contamination,
is the material between the samples assumed to be contaminated or clean?
How is it proposed to interpolate PCB concentrations between sample points?
This will have substantial impacts on the volume of soil assumed to be impacted.
These rules must be developed prior to commencing field activities. Vague
reference to the potential for delineation is made, but specific procedures
need to be established.
Dioxin / Furan Sampling
There is misplaced emphasis on PCBs when dioxins and furans, detected
in Lemon Lane Landfill by the City of Bloomington in 1986-87 at very high
concentrations (200 to 300 ppb) and potentially presenting a serious threat
to human health and the environment, are overlooked. Burning PCBs in the
presence of oxygen produces dioxins/furans. Assigning financial responsibility
for dioxin sampling has no bearing on the need for dioxin sampling. Therefore,
dioxin/furan analyses must be shifted in priority on the proposed list of
analytical procedures to be performed from it current position (last place)
to second in line, behind PCBs. Dioxin "hot spots" should receive
expedited remediation. Furthermore dioxin sampling should be performed on
all samples, not just those containing more than 400 ppm PCBs. The availability
of dioxin test kits is discussed later.
Vertical Distribution of PCBs
Documenting the vertical distribution of PCBs in each borehole may confirm
the movement of PCB-bearing DNAPL plumes away from the source through the
fill, soil and bedrock. However, the failure to encounter these plumes using
only 25 borings on a 10-acre landfill would in no way demonstrate their
absence. Similarly, the absence of PCBs over the sinkhole centers would
not show that PCBs do not enter bedrock or groundwater. Landfill leachate,
including DNAPLs with PCBs, could easily pass through the layer of native
soil under the landfill. The St. Louis Limestone, which is tile first bedrock
unit under the landfill, is intensely jointed and cracked and vulnerable
to dissolution by water. It is more similar to a bed of gravel than solid
bedrock. So a sinkhole is not required in order for liquids to be transported
rapidly in all directions. And the transport mechanisms for water, sediment
and DNAPLs would be different from each other.
Field Screening
I encourage the use of immunoassay field test kits for PCBs. They provide
useful results quickly, and at a fraction of the cost of performing lab
analyses. But they can provide misleading results if not interpreted correctly,
and they have not been validated for use on landfill material.
According to ENSYS a test that is calibrated to detect 400 ppm of Aroclor
1254, will require 2,000 ppm of Aroclor 1242 or 4,000 ppm of Aroclor 1016
to trigger a positive result. Similarly, if the test is calibrated to detect
400 ppm of Aroclor 1016, Aroclor 1242 will test positive at 80 ppm and Aroclor
1254 will test positive at 40 ppm. Millipore provides conservative results
by calibrating the detection limit to the least sensitive Aroclors. The
calibration standard must be defined in the sampling plan. Further, any
sample that is visibly stained should be automatically sent to the laboratory
for analysis because more than 5% oil in the sample can produce unreliable
results. High moisture content also leads to under-reporting of the PCB
content of the sample, and samples with more than 20 - 30% moisture content
should be dewatered prior to testing. In addition, the herbicide divron
can cause false positives.
The PCB test kits for soil have been validated for soil, not landfill
material, and a validation work plan must be prepared. We request an opportunity
to review and comment on the test kit validation work plan. Neither ENSYS
nor Millipore were aware of applications of the PCB test kits to landfill
material. Millipore suggested that the test kits could be used as screening
tools in the field but that all results should be verified in the lab.
Test kits are available at custom-set detection limits, and more than
one detection limit can be used for a single sample. I recommend that a
two tiered screening be used: first 400 ppm (as proposed) to identity samples
with gross contamination, followed by 50 ppm for samples that pass the initial
screening. This will provide useful information regarding the extent of
PCB contamination in the landfill.
I also encourage the consideration of immunoassay test kits for dioxins.
ENSYS offers dioxin test kits for use in the laboratory: unlike the PCB
test kit where extraction and testing occurs in the field, the dioxin extraction
is performed in the laboratory using standard methods and then the immunoassay
test kit is applied. It can detect 2378-TCDD in the part per trillion to
parts per quadrillion range and costs only $ 120 per test. Millipore expects
to have a dioxin test kit on the market in 6 months.
Additional Physical / Chemical Laboratory Testing
If the purpose of restricting extensive lab analyses to samples with
more than 400 ppm PCBs is to obtain a waste profile on the "hot spots"
so that treatment or disposal options can be explored, then there are additional
data describing physical and chemical waste properties that must be obtained
(e.g., TCLP, clay and organic content, oil and grease content, etc.). Each
technology vendor and land disposal operator should be contacted in advance
to identity parameters required for evaluation. |
