United States
Environmental Protection
Agency
Research and Development
Office of Health and
Environemntal Assessment
Washington, DC 20460
EPA/600/S8-91/007 May 1991
EPA Project Summary
Feasibility of Environmental
Monitoring and Exposure
Assessment for a Municipal
Waste Combustor at Rutland,
Vermont
The purpose of this multipollutant,
multimedia study was to determine
levels of contaminants In the ambient
air, soil, sediment, water and agricul-
tural products attributable to operation
of the municipal waste combustor
(MWC) In Rutland, Vermont. Samples
were collected between October 1987
and February 1989 at or near locations
predicted to have maximum deposition.
The results show that the measured
pollutant concentrations could not be
correlated with the emissions or op-
eration of the MWC. Evidence for this
conclusion comes from both qualitative
and quantitative evaluation of the mea-
sured pollutant concentrations in the
ambient air and environmental media,
as well as comparison with predicted
ambient air concentrations of the pol-
lutants using local meteorologic infor-
mation.
This Project Summary was developed
by EPA's Environmental Criteria and
Assessment Office, Cincinnati, OH, to
announce key findings of the research
project that Is fully documented In a
separate report of the same title (see
Project Report ordering Information at
back).
Introduction
This multipollutant, multimedia study was
designed to determine the levels of con-
taminants attributable to operation of a
municipal waste combustor (MWC) in
Rutland, Vermont, between October 1987
and February 1989. The sampling and
analysis techniques for the pollutants in the
various environmental media are discussed
followed by the analytical results. Ap-
proaches for evaluating the contribution of
the MWC emissions to the measured pollut-
ant concentrations in ambient air and the
environmental media are presented.
Sampling Methods
The levels of selected pollutants were
measured in the ambient air and environ-
mental media at or near predicted sites of
maximum deposition surrounding the MWC.
Air dispersion modeling of stack emissions
from the MWC prior to its operation was
conducted to select appropriate locations to
place ambient air monitors and to collect
environmental media samples. Both the
Industrial Source Complex Long-Term
(ISCLT) model and the LONGZ model used
source characteristics, terrain and meteo-
rologic data to predict average annual
concentrations in the vicinity of the MWC.
The models were run separately using 6
years of meteorologic data. As a result, a
four-station ambient air monitoring network
was established for collection of samples to
measure ground-level ambient air concen-
trations of pollutants.
Each air monitoring site had four sam-
plers, and two ambient-air monitoring sta-
tions were designed as co-located sites for
quality assurance purposes.
The four air monitoring samplers were
run for 24 hours every 12 days. No ambient
air samples were collected before operation
of the MWC. The first samples were collected
during November 1 987.
Dispersion modeling of emissions from
the Rutland MWC indicated that the area of
expected maximal deposition was within a
2-km radius of the facility. Therefore, lo-
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cations for collecting water, sediment, soil
and agricultural product samples were gen-
erally within this high-impact area. Grab
samples of water and sediment were taken
at five locations. A systematic grid sam-
pling technique was used to collect soil
samples atthe five sites. Milk, carrot, potato
and forage samples were collected from
farms in the area surrounding the incinera-
tor.
Water, sediment, soil and milk samples
were taken twice prior to operation of the
facility (October and November 1987) and
once after the combustor was operational
(June 1988). Potatoes and forage were
sampled twice (October and November
1987) and a carrot was sampled once be-
fore commencement of MWC operation
(October 1987).
Wind speed, wind direction, tempe'fafure,
relative humidity and solar radiation were
continuously monitored and recorded at
three of the air monitoring sites and rainfall
intensity and atmospheric pressure were
collected at one she.
Analytical Methods
In the ambient air, arsenic and chromium
were analyzed for total metal by neutron
activation (NAA). Beryllium, cadmium, lead,
and nickel in ambient air were analyzed by
an Inductively Coupled Plasma Emission
Spectrometer (ICP-AES). Benzo[a]pyrene
was analyzed by thin-layerchromatography,
PCBs by gas chromatography with electron
capture detection using a modified version
of EPA Method TO4, PCDD/PCDFs by
high resolution gas chromatography-high
resolution mass spectrometry, and mercury
by pyrolyzer-dosimeter.
Mutagenicity bioassay samples were
analyzed by the Salmonella typhimirium
histidine reversion assay.
The environmental media were analyzed
using U.S. EPA Standard Operating Pro-
cedures, which are dependent on the matrix
and pollutant. All environmental media
samples, except water, were analyzed for
the following pollutants: arsenic by graphite
furnace atomic absorption spectrometry;
beryllium, cadmium, chromium, lead and
nickel by direct aspiration atomic absorption
spectrometry; mercury by the cold vapor
technique of direct aspiration atomic ab-
sorption spectrometry; and PCBs and
PCDD/PCDFs by high resolution gas chro-
matography-high resolution mass spec-
trometry.
Water samples were analyzed for the
folbwing pollutants: arsenic and beryllium
by graphite furnace atomic absorption
spectrometry; cadmium, chromium, lead and
nickel by direct aspiration atomic absorption
spectrometry; and mercury by the cold va-
por technique of direct aspiration atomic
absorption spectrometry.
Analytical Results
Ambient Air
Most metals were measured above the
detection limit in only a few ambient air
samples. Arsenic was measured above its
detection limit of 0.0046-0.0047u.g/m3 in 71
98 samples, beryllium above its detection
limit of 0.2243 ng/m3 in 4/122 samples,
cadmium above its detection lim it of 0.0009-
0.0014 u.g/m3 in 2/122 samples, and chro-
mium above its detection limit of 0.0065-
0.0069 u.g/m3 in 1/98 samples. Lead was
the most frequently measured pollutant. It
was measured above its detection limit of
0.0061 u.g/m3in 108/122_samp|es. Nickel
' was measured above its detection limit of
0.0038-0.0077 ug/m3 in 3/122 samples, and
benzo[a]pyrene above its detection limit of
0.3348 ng/m3 in 43/131 samples. No PCBs
were measured above the detection limit of
0.7-0.8 ng/m3 in any samples collected.
Mercury concentrations were not reported
because of problems associated with pre-
cision.
Since only 14/135 samples had detect-
able concentrations for all PCDD/PCDF
congeners, isomer-specific 2,3,7,8-chlorine
substituted congener concentrations in
ambient air samples were determined us-
ing proportionality constants derived from
Rutland, VT ambient air data. Once the
proportion of each 2,3,7,8-chlorine substi-
tuted isomer was estimated, the concen-
trations were converted to 2,3,7,8-TCDD
equivalents using toxic equivalency factors
(TEFs). The TEFs relate the potency of
the different congeners to the potency of
2,3,7,8-TCDD, the most potent congener.
Total 2,3,7,8-TCDD equivalent concentra-
tions in ambient air samples ranged from
0.011-5.39 pg/m3.
Environmental Media
Concentrations of arsenic, beryllium,
chromium, lead, mercury and nickel in both
produce and forage were nondetectable.
The mean concentration of cadmium, which
was detectable in produce, was 0.2 and 0.3
mg/kg in October and November 1987, re-
spectively. The concentration of cadmium
in forage was detectable (0.1 mg/kg) in one
of two samples in November 1987 and was
nondetectable in all other produce and for-
age samples for both sampling rounds.
Concentrations of beryllium in milk were
nondetectable for all sampling periods and
sites. Chromium and lead concentrations
were found in milk in measurable quantities
at several sites in October and November
1987, but were below the detection limit
during the incinerator's operational period
(June 1988).
Water concentrations of arsenic, beryl-
lium and nickel were nondetectable at all
sites for all sampling periods. Cadmium
and mercury concentrations in water were
detectable at one site during one sampling
period, butthe measured concentration was
equal to the detection limit. Arsenic, beryl-
lium, cadmium and nickel concentrations in
water were at or equal to the detection
limits. Chromium and lead concentrations
in water exceeded the detection limit in
several samples collected in the sampling
periods before the MWC was operating
(October and November 1987).
All metals except cadmium and mercury
were found to be present in sediment in
detectable concentrations. Only one sample
each of cadmium and mercury were de-
tectable.
The majority of PCDD/PCDF isomer
concentrations in milk, sediment and soil
were nondetectable, and were set equal to
the detection limit for the purpose of calcu-
lating average 2,3,7,8-TCDD equivalent
concentrations.
Most of the 2,3,7,8-TCDD equivalent
average concentrations were derived from
values that were nondetectable. If the
concentration was less than the detection
limit, the concentration was conservatively
set equal to the detection limit. The TEF
approach was then applied to estimate the
2,3,7,8-TCDD equivalent concentration.
The average concentrations in the produce
and forage ranged from 4.88-11.1 pg/g.
Approaches for Determining
Source Contribution
Analysis of the incinerator as a source for
the measured pollutants in ambient air en-
compassed four approaches: (1) tons of
waste burned daily in the MWC were com-
pared with measured paniculate matter (PM-
10) concentrations, (2) mutagenic activity
was compared to PM-10 concentrations
and tons of waste burned, (3) congener
profiles of measured PCDD/PCDF in
Rutland ambient air were compared with
those of potential sources, and (4) daily
ambient air concentrations of pollutants that
were predicted from air dispersion model-
ing were compared with the measured
pollutant concentrations.
The pollutant concentrations measured
in Rutland ambient air when the incinerator
was in operation represented the total
concentration of each pollutant from both
the incinerator and other sources. In order
to determine if the concentrations of mea-
sured pollutants were primarily from the
MWC, the proportion of the pollutants at-
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tributable to other sources needed to be
assessed. Since an inventory of other
sources for the measured pollutants was
not available, source apportionment was
assessed by statistically comparing mea-
sured and predicted ambient air concentra-
tions. '
The Industrial Source Complex Short-
Term (ISCST) model in the Urban 3 Mode
was run, using Rutland meteorologic data,
to predict the ground-level ambient air
concentrations of pollutants in Rutland for
the same days on which the ambient air was
sampled at the four monitoring sites. The
Urban 3 Mode, an option of the ISCST used
to describe the surrounding topography,
was selected because the incinerator was
located in a rural area with complex terrain.
The ISCST was run using both discrete and
polar receptors. The discrete receptors
corresponded to the locations of the four
monitoring sites by using their Universal
Transverse Mercator (UTM) coordinates.
The approach for the analysis of source
contribution to the environmental media was
qualitative, comparing concentrations be-
tween the various sampling periods and
comparing pollutant concentrations detected
in Rutland with those described for other
geographical regions.
Conclusions
The objective of this study was to deter-
mine if there were human health risks at-
tributable to the operation of this incin-
erator. This objective could not be attained
because the majority of pollutants in the
ambient air and environmental media were
not present in concentrations that could be
detected by the analytical methods em-
ployed. This made a direct determination of
the contribution of the incinerator to the
measurable concentration of pollutants not
possible. Therefore, an analysis of the
likelihood that the incinerator was a primary
contributor to the measured pollutant con-
centrations was assessed using several
alternative approaches.
The conclusion reached by evaluation of
the collected field samples is that the mea-
sured concentrations of the pollutants in the
ambient air and environmental media can-
not be correlated with the emissions or
operation of the MWC. The MWC does not
appear to be the primary source of these
pollutants. Evidence for this conclusion
comes from both qualitative and quantita-
tive evaluation of the measured pollutant
concentrations in the ambient air and envi-
ronmental media, as well as comparison
with predicted ambient air concentrations of
the pollutants using local meteorologic in-
formation.
While this field study did not show that the
MWC was a primary contributor to the
measured levels of pollutants, the results
contain information about the background
levels of pollutants and the contribution of
other sources to the Rutland, Vermont area.
.S. GOVERNMENT PRINTING OFFICE: 1991 - 548-028/40005
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Norman E Kowal is the EPA Project Officer (see below).
The complete document consists of a report and appendices, entitled "Feasibility
of Environmental Monitoring and Exposure Assessment for a Municipal Waste
Combustor at Rutland, Vermont:"
Report (OrderNo. PB91-181917/AS; Cost: $ 39.00 subject to change)
Appendices (OrderNo. PB91-179 697/AS; Cost: $ 45.00 subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Off her can be contacted at:
Environmental Criteria and Assessment Office
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use $300
EPA/600/S8-91/007
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