NCD980602163_19961203_Warren County PCB Landfill_SERB C_Hirschhorn Report on Warren COunty PCB Landfill-OCR

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DATE:
TO:
'0'919 5-11 3527 NERL' A~IRD : l!B
U.S. ENVIRONMENTAL PROTECTION AGENCY
NATIONAL EXPOSURE RESEARCH LA.BORA TORY
AIR MEASUREMENTS RESEARCH DivlSION (MAIL DROP 44)
RESEARCH 1Rl.\NGLE PARK, NORTH CA.ROLINA 27711
TELEPHONE 9l9-S41-306S FACSD.m.E 919-541-3527
E-MAIL lewis. [e-mail]
FAX l\1ESSAGE
3 December 1996 NUMBER OF PAGES: 3
(including cover)
Bill Meyer Fax No.: 715-3605
Telephone:
FROM: Dr. Robert G. Lewis
USEPA (MD-44)
Research Triangle Park, NC 27711
SUB.JECT: Hirschorn Report on Warren County PCB Landfill
MESSAGE:
[4]001 :003
I was out until today and have just reviewed the above-referenced report that you faxed to
me yesterday.
The 1983 EPA paper (on which I was lead author) that Dr. Hirschom attacked in his
rep on was published in Environmental Science & Technology, a peer-reviewed journal widely
recognized as the leading journal in the world on environmental monitoring. Prior to publication,
it underwent rigorous technical review within the EPA and by two or more leading experts
outside the Agency. Therefore, our statements that PCB emissions from the landfill were
negligible at the time of the study were supported by the highest level of technical review.
It is clear from the data presented in Table II of our paper that no significant PCB
concentrations could be measured in the air surrounding the landfill, even at one meter distance
from the main vent pipe. As the paper states, "only four of 39 ambient air samples analyzed
contained detectable quantities of PCB." These were positive only for Aroclor 1260 (the least
volatile of the two .¼odors monitored) and "did not appear to correlate with proximity to the
vents." It would be clear to any analytical chemist or anyone with environmental monitoring
expertise that these were likely false-positive results. The levels detected were 0.01 to 0.07
µg/m3, at or very near the method detection limit (0.01 -0.02 µg/m3). Had they been "real," the
more volatile Aroclor 1242 should have been found at much higher concentrations, as it was in
main and upper leachate vent pipes (see Table I). The lack of correlation of the measured ambient
air levels with proximity to the vent pipes, taken with the fact that A.roclor 1242 was the only
analyte identified in the air even though Aroclor 1260 was at much higher concentrations in the
vent gas, conclusively demonstrates that the vent pipes were not the source of the PCBs detected
in air, even if the measured air values were real. It should also be noted that PCBs were
l2 l (l3 .-96 · 1:.i:01 '0'919 5-U 352i .KERL / A~IRI>,. 11B (4]002 .-003
ubiquitaus in the ambient air in the United States, typically at 0.005 to 0.01 µg/m3, at the time of
the Warren county air monitoring effort.
Our air monitoring results were also consistent with both the air emissions models applied
to the vent measurements. As we stated in the paper, the models predicted that no measurable air
concentrations of PCBs would result at 14 meters from the main vent and beyond.
In his analysis of the data presented in our paper, Dr. Hirshom refers to measurements of
"Arochlors" (sic) obtained '(at" the main vent (120.2 µg/m3 for Aroclor 1242). The vent pipe.
measurements shown. in Table I were made within the vent pipes, not in the air at or near the
vents. Hence, they cannot be compared with the ambient air measurements made at the
uncontrolled sites in Indiana and reported in our paper. There were other major differences
between the Warren County and Indiana sites. The Warren County site was brand new and
should have been emitting at a maximum rate. The Indiana disposal sites were old (before 1972,
as stated in our paper). The PCB-contaminated soil in Warren County was underground, in the
thermic temperature regime, and should not have been affected by ambient air temperature (i.e.,
emission rates should have been the same whether it was summer or winter at the time of
monitoring). In Indiana, PCB-contaminated surface soil was abundant; thus, emissions were
greate: in summer when the sun heated the soil. As we said in our paper, the PCBs measured in
the vent pipes in Warren County were be transported by methane from decaying organic matter
(primarily grass excavated along with the roadside soil) and should have declined greatly once
that matter bad decayed. Therefore, Dr. Hirshorn's statement on p. 4 6fhis repon that the "high
levels found at the Warren County Landfill were quite comparable, and perhaps even greater than
the levels found above the other three uncontrolled landfills" is absolutely without merit.
As lead author of the ES&T paper, the interpretations of our findings were principally
mine. However, the report provided to EPA by Battelle Memorial Institute, who did the air
monitoring for the Agency under contract, reached the essentially the same conclusions ( see
attachment).
Anachment
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SECTION 2
CONCLUSIONS
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The conclusions drawn for results of this study are surm,arized below.
(1) The principal source of emissions from the landfill originate from
the main vent pipe. The average PCB concentrations of Aroclor 1242
and Aroc1or 1260 measured in the main vent emissions during the
study were 123,000 ng/scm {...,100 ppb) and 2,000 ng/scm (""'2 ppb).
respectively. These concentrations are substantially lower than
the current occupational standards for workplace atmospheres which
range from 0.4 to 0.8 ppm.
(2) Ambient air PCB levels on and surrounding the landfill site (even
as close as one meter from the main vent) were found to be at or
below minimum detection limits (6 to 10 ng/m3) for the sampling
method. PCB levels generally present in the atmosphere throughout
the U.S. are in the range of 5 to 10 ng/m3.
{3) Mathematical modeling predicts that ambient air PCB concentrations
on and in the vicinity of landfill resulting from the main vent
pipe emissions may be approximately 106 to 109 times lower than the
detectioh limits for sampling method used in this study. PCB
contributions to the ambient air from the landfill based on the
model predictions are insignificant when compared to general
ambient air PCB levels in the U.S.
(4) It is anticipated that the low PCB emission rate from the landfill
will be reduced still further as decay of organic matter producing
the methane and other gases emanating from the vents subsides. The
reduction of hydraulic pressure by removal of water from the site
should also reduce ·emission rates substantially.
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