United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-95/129 August 1995
vvEPA Project Summary
Municipal Solid Waste (MSW)
Combustor Ash Demonstration
Program "The Boathouse"
Frank J. Roethel and Vincent T. Breslin
This report presents the results of a
research program designed to exam-
ine the engineering and environmental
acceptability of using municipal solid
waste (MSW) combustor ash as an ag-
gregate substitute in the manufacture
of construction quality cement blocks.
Approximately 350 tons of MSW com-
bustor ash was combined with Port-
land cement to form standard hollow
masonry blocks using conventional
block making technology. The result-
ant stabilized combustor ash (SCA)
blocks were used to construct a boat-
house on the campus of the University
at Stony Brook.
Periodically, over a 30-mo period, air
samples collected within the boathouse
were examined and compared to ambi-
ent air samples for the presence and
concentrations of suspended particu-
lates, particulate and vapor phase
PCDD/PCDF, volatile and semi-volatile
organic compounds and volatile mer-
cury. Analyses of the air samples indi-
cate no statistical difference between
the air quality within the boathouse and
ambient air samples. Rainwater
samples following contact with the
boathouse walls were collected and
analyzed for the presence of trace ele-
ments. Results show that the SCA
blocks retain contaminants of environ-
mental concern within their cemen-
titious matrix. Soil samples were
collected prior to and following the con-
struction of the boathouse and the re-
sults suggest that block debris
generated during the boathouse con-
struction was responsible for elevated
concentrations of trace elements in sur-
face soils. Engineering tests show that
the SCA blocks maintain their struc-
tural integrity and possess compres-
sive strengths similar to standard
concrete blocks.
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory, Cincinnati, OH,
to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
Since 1985, scientists at the Waste Man-
agement Institute (WMI) of the Marine Sci-
ences Research Center at the University
at Stony Brook have been assessing the
feasibility of using stabilized MSW com-
bustor ash in a variety of marine and
terrestrial applications. To date, two artifi-
cial reefs have been constructed on the
sea floor of Long Island Sound using
blocks of stabilized combustor ash. Over
the past six years, results showed there
was no release to the environment of ei-
ther organic or inorganic constituents of
environmental concern from the stabilized
combustion residue blocks placed in Con-
science Bay.
A second series of studies were initi-
ated at Stony Brook to assess the poten-
tial use of MSW combustor ash as an
aggregate substitute in the manufacture
of construction quality cement blocks. Us-
ing combined ash from several resource
recovery facilities, scientists manufactured
standard construction quality cement
-------
blocks that meet or exceed ASTM perfor-
mance standards.
The third series of studies began in
1990 with the construction of the boat-
house. This phase of the investigation fur-
thered the structural testing of the ash
blocks and extended the scope of the
environmental and health impact assess-
ment in a terrestrial setting. Research was
conducted to measure changes in ash
block chemistry, surrounding soil chemis-
try, rain water chemistry, air quality within
the boathouse, and to evaluate long-term
structural performance of the stabilized
combined and bottom ash blocks.
Results of this study lead to the manu-
facture of 14,000 stabilized ash blocks,
using both bottom and combined ash from
the Westchester County waste to energy
(WTE) facility, located in Peekskill, NY.
Block fabrication employed conventional
block making machines currently used by
the industry.
This investigation was initiated follow-
ing the completion of construction activi-
ties. The primary objectives of this study
were to determine if:
1)air quality within the boathouse was
adversely impacted due to the
presence of the SCA blocks, and was
substantially different from outdoor
ambient air samples;
2) metals of environmental concern leach
from the SCA blocks following a
rainfall event;
3)concentrations of trace metals
associated with the soils surrounding
the boathouse become elevated
following the construction; and,
4)weathering effects adversely impact
the structural integrity of the SCA
blocks.
Boathouse Construction
Approximately 100 tons of combined ash
and 250 tons of bottom ash were col-
lected from the Westchester County Re-
source Recovery Facility, Peekskill, NY in
spring 1990. The collected ash was pro-
cessed at an aggregate processing facility
on Long Island to remove ferrous metals
and achieve the necessary particle size
distribution for block fabrication. Following
processing, the ash was transported to
Barrasso & Sons, Islip Terrace, NY, a
local cement block manufacturer, where
approximately 4,000 combined SCA blocks
and 10,000 bottom SCA blocks were pro-
duced.
The boathouse measures 27 m in
length, 18 m in width and 7 m in height.
The western and northern exterior walls
were constructed using bottom SCA blocks
while the eastern and southern exterior
walls are composed of combined SCA
blocks. The interior of the structure is di-
vided into five separate rooms. All interior
walls are constructed using bottom SCA
blocks. The boathouse is supported by
conventional concrete footings and pad.
Due to the impracticality of removing
SCA blocks directly from the boathouse
walls for experimentation, test walls were
fabricated using both bottom and com-
bined SCA blocks remaining following con-
struction. Three walls were constructed
one using the bottom ash blocks, a sec-
ond using the combined ash blocks and a
third using conventional cement blocks that
were purchased from a local masonry sup-
plier. Each wall was composed of 64
blocks, stacked 8 blocks high and 8 blocks
across and was located adjacent to the
boathouse.
Results and Discussion
Air Quality Determinations
Air samples were collected every 4 mo
over a 2-yr period and analyzed for total
suspended particulates, particulate and
vapor phase PCDD/PCDF, volatile mer-
cury and volatile and semi-volatile organic
compounds. All air quality analyses, in-
cluding PCDD/PCDF determinations, were
conducted by the New York State Depart-
ment of Health (DOH) in their laboratories
in Albany, NY.
Total Suspended Particulates
(TSP)
Boathouse TSP concentrations ranged
from 4.8 |ig/M3 to 24 |ig/M3, with the ex-
ception of a spike of 168 |ig/M3 in Sep-
tember 1992. The outdoor control site also
experienced a spike in particulate con-
centration, of 120 |o,g/M3, during Septem-
ber 1992, but otherwise maintained a
concentration range from 8.4 |ig/M3 to 64
|ig/M3 (Table 1). On average, suspended
particulate levels measured at the outdoor
control site were higher than inside the
boathouse. A two-way ANOVA compar-
ing the TSP data collected inside the boat-
house to the outdoor control site yielded
no statistical differences between these
two data sets. The average TSP loads,
both inside the boathouse and at the out-
door control site were well below the OSHA
criteria of 5 mg/M3
PCDD and PCDF
Concentrations
Tables 2 and 3 present the particulate
and vapor phase concentrations of PCDDs
and PCDFs measured from Hi-volume air
sampling experiments conducted both in-
side the boathouse and at an outdoor
control site. For five of the six sampling
events, total PCDD/PCDF concentrations
within the boathouse environment ranged
between 0.19 pg/M3 to 3.62 pg/M3. The
September 1992 sampling event resulted
in a total PCDD/PCDF concentration of
17.86 pg/M3 At the control site, for five of
the six sampling events, total PCDD/PCDF
concentrations ranged between 0.70 pg/
M3 to 4.00 pg/M3. The May 1992 sampling
event resulted in a total PCDD/PCDF con-
centration of 22.5 pg/M3.
The results of a two-way analysis of
variance comparing total individual PCDDs
and PCDFs inside the boathouse to the
outdoor control site with respect to time
revealed that no statistically significant dif-
ference existed for any of the isomers.
Volatile Mercury
Volatile mercury was detected during
one of the six sampling events for both
inside the boathouse and outdoor control
site. The concentration of mercury mea-
sured inside the boathouse during May
1992 was 58 ng/M3, while the outdoor
control site during January 1992 was mea-
sured at 87 ng/M3. Detection limits varied
from 21-73 ng/M3 according to the volume
of air sampled and sensitivity of the ana-
lytical procedures employed.
No significant difference was measured
for mercury concentrations measured in-
side the boathouse and the outdoor con-
trol site. All mercury concentrations were
well below the NIOSH toxicity limit of
50,000 ng/M3.
Volatile Organic Compounds
Two analytical techniques were em-
ployed in evaluating the presence and con-
centration of volatile organic compounds
(VOCs). The USEPA canister method was
used to measure 13 VOCs and the
Porapak-N method was used to measure
44 VOCs. Porapak-N is a cavity rich poly-
mer on which VOC's are easily trapped if
an air flow is directed over the material.
Between these two methods, the pres-
ence and concentration of 46 VOCs was
determined.
Of the 46 VOCs analyzed, 11 were
detected inside the boathouse and 12 were
detected at the outdoor control site. Ex-
cept for methylene chloride, every com-
pound detected inside the boathouse was
also observed at the outdoor control site.
The compounds detected both inside the
boathouse and outdoor control site in-
cluded chloroform, chloromethane,
tetrachloroethene, ethylbenzene, m/p-xy-
lene, o-xylene, carbon tetrachloride, ben-
zene, 1,1,1-trichloroethane, and toluene.
Hexane was detected only at the outdoor
control site. Table 4 lists all the detected
VOC concentrations for both the canister
and Porapak-N sampling methods.
-------
Table 1. Total Suspended Particulate Concentrations
Concentration (\ig/Nr)
Sampling Events
Jan-92
May-92
Sept-02
Jan-93
May-93
Sept-93
Inside Boathouse
8.9
24
168
4.8
11
6.8
Outside Boathouse
44
61
120
64
NA"
8.4
May 93 control sample was not available due to analytical problems.
Table 2. PCDD/PCDFConcentrations (pg/M3) Measured Within the Boathouse
Inside Boathouse
Analyte
2378 TCDD
12378 PCDD
123478 HxCDD
123678 HxCDD
123789 HxCDD
1234678 HpCDD
12346789 OCDD
2378 TCDF
12378 PCDF
23478 PCDF
123478 HxCDF
123678 HxCDF
234678 HxCDF
123789 HxCDF
1234678 HpCDF
1234789 HpCDF
12346789 OCDF
OTHER TCDD
OTHER PCDD
OTHER HxCDD
OTHER HpCDD
OTHER TCDF
OTHER PCDF
OTHER HxCDF
OTHER HpCDF
TOTAL
Jan-92
<0.04
<0.04
<0.06
<0.06
<0.05
0.151
1.05
<0.03
<0.03
<0.04
<0.03
<0.04
<0.04
<0.04
0.077
<0.07
0.156
<0.04
<0.04
0.138
0.167
0.121
0.201
0.16
0.032
2.903
May-92
<0.05
<0.07
<0.12
<0.11
<0.11
<0.17
0.762
<0.04
<0.05
<0.06
<0.06
<0.06
<0.08
<0.07
<0.10
<0.17
<0.19
<0.05
<0.07
<0.11
0.284
0.328
0.225
0.182
<0.10
3.621
Sep-92
<0.013
0.02
<0.007
0.026
0.02
0.17
0.55
1.1
0.89
0.61
0.41
0.19
0.025
0.007
0.11
0.026
0.094
0.089
0.023
0.054
0.16
6
6.8
10.68
0.044
17.86
Jan-93
<0.001
<0.001
0.002
<0.003
<0.005
0.015
0.23
0.007
<0.003
<0.004
<0.007
<0.003
<0.002
<0.002
0.015
<0.002
0.016
0.003
<0.002
<0.002
0.082
0.01
<0.002
0.011
0.003
0.186
May-93
<0.003
<0.003
<0.005
<0.005
<0.004
0.064
0.23
0.014
0.007
<0.002
0.003
<0.003
<0.003
<0.003
0.019
<0.009
<0.010
<0.003
<0.003
0.019
0.046
0.071
0.03
<0.003
<0.003
0.361
Sep-93
0.007
<0.006
0.01
<0.009
0.008
0.076
0.25
0.02
0.006
0.01
0.011
0.008
0.009
0.008
0.023
0.011
0.028
0.007
<0.006
0.025
0.114
0.079
0.02
0.023
0.007
0.502
Eight of the twelve compounds detected
were greater inside the boathouse than
the outdoor control site. It is generally the
case that observed VOCs indoors are
greater than measured outdoors. More
importantly, 10 of the 11 compounds ob-
served inside the boathouse were also
detected at the outdoor control site, indi-
cating the major factors influencing VOC
content in the air were the same for both
sampling sites.
Rain Water Evaluations
Rain water sampling consisted of four
sample types; bottom ash blocks (BA),
combined ash blocks (CA), cement blocks,
and a blank. Two replicates of each of
these four sample types were collected
during each of the eight sampling events,
distributed over a 29-mo period. Immedi-
ately following sample collection, the pH
and volume of the rain water samples
were recorded prior to chemical analyses.
Chemical analyses consisted of measur-
ing the concentration of calcium, cadmium,
copper, and lead in the rainwater samples.
Rain Water pH
The pH was measured to ascertain the
degree of influence the ash blocks may
have had on rain water chemistry. The pH
of the BA and CA rain samples decreased
from 10.21 to 6.7 and 10.3 to 6.2, respec-
tively, while the cement rain samples de-
creased from 9.5 to 6.7 following 29-mo
of block exposure (Table 5). Although a
decrease in pH was measured over time,
the measured decrease in pH for the BA
and CA rain water samples was not uni-
form. During this period the blank rain
sample pH ranged from 4.9 to 6.9.
Rain Water Chemistry
Rain water chemistry was evaluated to
determine the extent of inorganic leaching
from the ash blocks. The rain water
samples were each analyzed for a repre-
sentative sub-set of the elements mea-
sured in the ash blocks including calcium,
copper, cadmium, and lead (Table 6).
Results of a two-way ANOVA showed
that the calcium concentration in the ce-
ment block rain water samples was statis-
tically greater than the BA, CA, and blank
rain water samples. Calcium content of
the BA and CA rain water samples was
not statistically different from the blank
rain water samples. Calcium in the ce-
ment rain samples ranged from 9.5 to
25.6 mg/L, whereas the BA, CA and blank
samples ranged from 0.3 to 1.9 mg/L,
with one outlyer of 12.9 mg/L.
The results of a two-way ANOVA
showed that no significant difference in
cadmium concentration existed between
the ash block and blank rain water
samples. Cadmium content of the CA block
rainwater ranged from <0.3 to 2.1 |ig/L,
while the cement block rain water ranged
from <0.3 to 2.6 jag/L
Copper in the cement and blank rain
water samples were measured at <0.03
mg/L for every sampling event. Copper
concentration in the BA rain water ranged
from 0.51 to 0.70 mg/L, while the CA rain
water ranged from <0.03 to 0.30 mg/L.
The BA rain sample collected in May
1992 had a lead concentration of 17.9 |ig/
L. All remaining rain water samples were
below the instrumentation detection limit
of <2.5 |ig/L. The single detected lead
value of 17.9 |ig/L value surpassed the
USEPA drinking water limit for lead of 15
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Table 3. PCDD/PCDF Concentrations (pg/M3) Measured
Outside Boathouse - Control Site
Analyte
2378 TCDD
12378 PCDD
123478 HxCDD
123678 HxCDD
123789 HxCDD
1234678 HpCDD
12346789 OCDD
2378 TCDF
12378 PCDF
23478 PCDF
123478 HxCDF
123678 HxCDF
234678 HxCDF
123789 HxCDF
1234678 HpCDF
1234789 HpCDF
12346789 OCDF
OTHER TCDD
OTHER PCDD
OTHER HxCDD
OTHER HpCDD
OTHER TCDF
OTHER PCDF
OTHER HxCDF
OTHER HpCDF
TOTAL
Jan-92
<0.04
<0.05
<0.07
<0.07
<0.07
0.243
1.21
<0.04
0.079
0.051
0.077
0.049
<0.05
<0.05
0.139
<0.09
0.172
<0.04
<0.05
0.205
0.249
0.162
0.458
0.246
0.044
4.004
May-92
<0.09
<0.13
<0.23
<0.22
<0.21
<0.36
0.847
1.067
1.006
0.496
0.267
<0.12
<0.14
<0.14
<0.19
<0.32
<0.38
<0.090
<0.130
<0.220
<0.460
7.914
6.392
0.885
<0.190
22.49
Sep-92
<0.028
0.002
<0.003
0.006
<0.005
0.067
0.68
0.033
0.006
0.009
0.013
<0.008
0.009
0.001
0.045
0.009
0.096
0.055
0.027
0.046
0.063
0.197
0.077
0.046
0.009
0.764
Jan-93
<0.016
<0.003
<0.011
0.029
0.032
0.29
1.57
0.052
0.016
0.035
0.05
0.018
0.022
0.007
0.11
0.011
0.12
0.032
0.011
0.059
0.3
0.058
0.089
0.053
0.079
1.383
May-93
<0.012
<0.013
<0.018
<0.017
<0.015
0.094
0.32
0.033
0.018
0.023
<0.010
<0.01
<0.012
<0.011
0.027
<0.028
<0.046
<0.012
<0.013
0.049
0.086
0.055
0.069
0.026
<0.003
0.70
Sep-93
<0.014
<0.018
<0.027
<0.025
<0.023
0.16
0.54
0.028
0.016
0.029
0.028
0.022
0.027
<0.015
0.14
0.026
0.11
<0.014
<0.018
0.15
0.21
0.152
0.115
0.103
0.034
1.394
Table 4. Range of VOC Concentrations
Analyte
ug/M3
Hexane
Chloroform
Chloromethane
Methylene Chloride
Tetrachloroethene
Ethylbenzene
M/P-Xylene
O-Xylene
Carbon Tetrachloride
Benzene
1, 1, 1 -Trichloroethane
Toluene
Detection
Method
Canister
Porapak-N
Canister
Canister
Porapak-N
Canister
Canister
Canister
Porapak-N
Can/P-N
Porapak-N
Can/P-N
Inside
Boathouse
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Table 6. Metal Concentrations in Rain Water Samples
Analyte
Cd (g/L)
Cu (mg/L)
Treatment
Bottom ash
Combined Ash
Cement
Blank
Bottom ash
Combined Ash
Cement
Blank
Concentration
Jan 92
May 92
Sep92
Jan 93
Sep93
Dec 93
Mar 94
<0.3
<0.3
<0.3
<0.3
0.6 (0.2)
0.3 (0.02)
<0.03
<0.03
5.1(5.1)
2.1 (0.6)
<0.3
<0.3
0.7(0.6
0.1 (0.02)
<0.03
<0.03
<0.3
<0.3
2.6 (3.3)
<0.3
0.54 (0.69
0.04 (0.02)
<0.03
<0.03
1.4 (1.4)
1.7(0.7)
<0.3
1.2 (1.3)
0.51 (0.7)
<0.03
<0.03
<0.03
<0.3
<0.3
<0.3
0.3 (0.2)
0.55(0.7)
0.05(0.01)
<0.03
<0.03
2.1 (1.9)
<0.3
<0.3
<0.3
<0.03
<0.03
<0.03
<0.03
<0.3
<0.3
<0.3
<0.3
<0.03
<0.03
<0.03
<0.03
May 94
Ca (mg/L)
Bottom ash
Combined Ash
Cement
Blank
2.5(0.1)
3.0(0.7)
11.2 (4.7)
1.9 (1.6)
1.8 (0.4)
4.1(1.1)
10.6 (2.6)
0.3(0.1)
4.7(0.4)
6.0 (1.9)
22.2 (4.4)
12.9 (17.2)
2.6(0.7)
3.7(0.1)
25.6 (3.9)
0.4 (0.0)
2.2 (1.0)
4.1 (0.7)
15.4 (6.3)
1.7(0.6)
6.7(0.8)
5.1(1.4)
9.5 (0.8)
1.4 (0.2)
7.6 (0.6)
9.2 (2.8)
21.7(1.4)
0.5(0.0)
10.2 (2.9)
24.9 (2.5)
10.2 (0.9)
0.6 (0.8)
<0.3
<0.3
<0.3
<0.3
<0.03
<0.03
<0.03
<0.03
Pb (g/L)
Bottom ash
Combined Ash
Cement
Blank
<2.5
<2.5
<2.5
<2.5
17.9 (23.5)
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
<2.5
Table 7. Mean and Standard Deviation Range of Metal Concentrations (fig/g) Measured in Soil Samples
Analyte Treatment Soil Depth
Pre-Boathouse
Post-Boathouse
Ca Bottom Ash 2
8
14
20
Combined Ash 2
8
14
20
Control 2
8
14
20
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
Not Determined
2660 (1650) - 46300 (31300)
610 (40) - 1880 (2120)
210 (50) - 720 (440)
160 (15) - 600 (180)
300 (260) - 14600 (1160)
250 (180) - 1550 (280)
170(190)- 1600(1180)
150 (100) - 810 (160)
250 (20) - 380 (50)
105 (15) -410 (60)
100 (60) - 270 (50)
50 (20) - 220 (90)
Cd Bottom Ash
Combined Ash
Control
Cu Bottom Ash
Combined Ash
Control
2 <0.01 - 0.03 (0.01) 0.19 (.03) - 0.90 (0.27)
8 Not Determined 0.11 (.03) - 0.99 (.021)
14 Not Determined 0.05 (.03) - 2.33 (2.58)
20 <0.01 - 0.03 (0.01) .045 (.01) - 1.17 (0.75)
2 <0.01 - 0.24 (0.02) 0.14 (.07) - 1.54 (0.8)
8 Not Determined 0.12 (0.04) - 1.47 (0.85)
14 Not Determined 0.095 (.05) - 0.95 (0.5)
20 <0.03 (0.01)-0.05 (0.04) 0.23 (0.2) - 0.98 (0.8)
2 <0.01 - 0.08 (0.01) 0.09 (0.02) - 0.67 (1.0)
8 Not Determined 0.11 (0.1) - 0.67 (0.5)
14 Not Determined 0.06 (0.03) - 0.91 (1.0)
20 <0.01-0.11 (0.03) 0.044 (0.009) - 0.78 (0.36)
2 6.5 (0.3) - 17.4 (0.1) 10.4 (4.0) - 100 (140)
8 Not Determined 4.8 (0.9) - 49.1 (55)
14 Not Determined 4.3 (.05) - 25.5 (5.2)
20 5.8 (0.2) - 6.8 (0.3) 4.7 (0.4) - 27.5 (20)
2 5.8).6)-7.1 (1.2) 8.8 (6.3) - 100 (74)
8 Not Determined 6.2 (3.0) - 46.1 (19)
14 Not Determined 4.5 (6.2) - 50.3 (46)
20 3.5 (0.2) - 6.8 (0.3) 5.1 (5.6) - 26.0 (3.6)
2 6.5 (0.9) - 7.3 (0.6) 5.8 (1.7) - 14.9 (3.4)
8 Not Determined 6.3 (1.0) - 16.6 (6.8)
14 Not Determined 4.8 (1.0) - 12.5 (0.50
20 4.2 (0.1) - 4.3 (0.3) 3.3 (1.0) - 19.9 (21)
(continued)
cadmium were present in trace amounts,
whereas silver and selenium were never
detected.
Chemical Composition of Ash
Blocks
The metal content of the bottom and
combined ash samples (Table 8) were
generally greater than the BA and CA
blocks (Table 9). This concentration dif-
ferential resulted from a dilution effect
caused by the addition of Portland ce-
ment and sand to the ash during block
fabrication. The BA and CA blocks con-
tained 55% and 64% ash respectively.
The concentration of inorganic constitu-
ents measured in the ash blocks should
have equaled either 55% or 64% of the
inorganic material measured in the ash
sand samples, plus any additional contri-
bution from the sand and cement com-
prising 45% and 36% of the BA and CA
blocks respectively. The metal concentra-
tions measured in the control cement
blocks (Table 10) were used to roughly
estimate the contribution of the ash ce-
ment fractions of the BA and CA blocks.
The measured concentrations in the BA
blocks for arsenic, magnesium, manga-
nese, sodium, and zinc, and in the CA
blocks for arsenic, calcium, iron, and nickel
did not agree with the calculated concen-
trations. The remaining nine metal con-
centrations in the BA and CA blocks were
within expected concentrations.
The differential between the expected
and actual ash block metal concentrations
is an artifact of the non-homogeneity of
the block mixes. The machinery which fed
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Table 7, Continued
Analyte Treatment
Soil Depth
Pre-Boathouse
Post-Boathouse
Pb Bottom Ash 2
8
14
20
Combined Ash 2
8
14
20
Control 2
8
14
20
Zn Bottom Ash 2
8
14
20
Combined Ash 2
8
14
20
Control 2
8
14
20
6.7(0.5)- 13.0(6.2)
Not Determined
Not Determined
7.9(0.2)- 11.0(2.7)
7.0 (1.0) - 7.5 (0.9)
Not Determined
Not Determined
6.0 (0.3) - 9.9 0.2)
21.0 (1.6) - 40.0 (3.3)
Not Determined
Not Determined
6.4 (0.2) -2 1.0 (1.3)
17.0 (0.40) - 19.0 (0.9)
Not Determined
Not Determined
17.0 (0.4) - 18.0 (4.3)
13.0 (1.6) - 55.0 (14.6)
Not Determined
Not Determined
15.0 (0.5) - 19.0 (0.4)
20.0 (1.4) - 23.0 (1.0)
Not Determined
Not Determined
14.0(0.4)- 16.0(1.1)
17.2 (11. 6) -40.6 (37.6)
5.6 (1.5) -52.3 (40.7)
6.2 (1.5) - 15.0 (9.5)
6.2(1.1)- 14.2(5.2)
13.4 (4.3) - 41.3 (17.4)
7.6 (0.5) - 19.6 (17.5)
3.6 (2.0) -26.2 (17.9)
4.5(0.3)- 16.8(12.9)
9.4 (8.4) -23.7 (1.1)
12.1 (4.0) - 20.9 (5.9)
5.6(1.9)- 11.7(2.2)
4.6 (4.4) - 6.8 (3.4)
53.0 (23) - 170 (21)
15.7 (24) -46.6 (12)
8.5 (2.1) - 48.6 (37)
16.5 (2.8) - 74.9 (80)
23.0 (7.2) - 140 (85)
17.8 (2.0) - 75.3 (20)
14.0(5.7) -51.0(11)
17.0 (0.2) -41.1 (11)
17.1 (12) -28.7 (2.8)
14.2 (9.3) - 31.2 (2.5)
13.5 (16) -29.4 (8.7)
10.8 (1.4) - 20.9 (2.5)
TableS, Mean and Std. Dev. Concentration of Metals Measured in MSW Combustor Ash
Analyte ([ig/g)
Bottom Ash
Combined Ash
Fe
Ca
Al
Na
Mg
K
Zn
Pb
Cu
Ba
Cr
Mn
Ni
As
Cd
Ag
Se
89100 (15400)
64700 (7250)
51700(3200)
47800 (1850)
10500 (400)
7500 (60)
6080 (220)
3260 (750)
2200 (340)
730 (65)
250 (10)
130 (10)
130 (20)
20.4 (3.2)
26.5 (3. 1)
<5
<19
80200 (1900)
72000 (3340)
5200 (3700)
37500 (750)
11800(310)
11100(400)
5370 (120)
4070 (120)
1600 (330)
870 (45)
220 (40)
930 (30)
140 (20)
<25
59.4 (10)
<5
<25
the constituents (sand, ash, cement, and
water) during block fabrication lacked the
precision required to make each block
chemically identical. Concrete block manu-
facturing does not require identical chemi-
cal composition. The boathouse blocks
were manufactured in twelve separate
batches, which added to the chemical de-
viance between blocks. Variability in the
block mixes was further demonstrated by
large standard deviations and concentra-
tion differences between samples encoun-
tered in block chemistry.
Trends Observed for the Block
Metal Concentrations
In the BA blocks, calcium, chromium,
sodium, and aluminum displayed concen-
tration ranges that consistently overlapped
each other for every sampling event.
In the CA blocks, lead, iron, magne-
sium, calcium, cadmium, chromium, po-
tassium, sodium, manganese, barium, zinc,
and aluminum displayed overlapping con-
centration ranges for each sampling event.
Nickel concentrations in the CA blocks
during November 1993 were greater than
measured from November 1991 to May
1993 (Table 8).
Of the seventeen metals measured, only
arsenic and copper appeared to decrease
with time in both the BA and CA blocks.
Ranges are discussed in the full report.
Block Compressive Strengths
Engineering studies conducted over a
period of 30 mo show that the ash blocks
have maintained their structural integrity
possessing compressive strengths equal
to conventional cement blocks. The com-
pressive strengths of all BA, CA and con-
trol blocks are outlined in the full report.
Conclusions
Both bottom and combined MSW com-
bustor ash, when combined with Portland
cement, can be successfully stabilized into
conventional construction quality cement
blocks. The construction of a boathouse
on the campus of the State University of
New York demonstrated the potential for
this utilization strategy. Engineering stud-
ies conducted over a period of 30 mo
show that the ash blocks have maintained
their structural integrity possessing com-
pressive strengths equal to conventional
cement blocks.
Air quality investigations demonstrate
that within the boathouse the concentra-
tions of suspended particulates, PCDD/
PCDF, volatile organic compounds and
volatile mercury are statistically similar to
ambient air.
The pH and Ca content of rain water
increased following contact with the stabi-
lized ash blocks. Trace amounts of cop-
per were measured following rain water
contact with bottom ash blocks, but these
concentrations were below public drinking
water standards.
Enrichment in the inorganic content of
surface soils was observed when com-
pared to control site soils. Given the lim-
ited leaching of elements from the ash
blocks surface soil elemental enrichment
is attributed to ash block debris resulting
from the construction of the boathouse.
Measurements of the chemical compo-
sition of the ash blocks reveal a non-
homogeneous mix of reactants (ash, sand,
Portland cement). The machinery used in
the manufacture of the ash blocks lacks
the precision to consistently blend the re-
actants in identical fashion. Numerous
batches, each potentially having a slightly
different ratio of ingredients, were required
in fabricating the nearly 14,000 blocks used
in the construction of the boathouse. The
data suggest that each batch was suffi-
ciently different in its chemistry to render
non-conclusive any evaluation of block
-------
Table 9. Mean and Standard Deviation of Inorganic Concentrations (gig) Measured in Stabilized Ash Blocks
Pre-Treatment Post-Treatment
Analyte
Block Type
Nov91
May 92
Nov92
May 93
Nov93
Major Metals
Ca
Fe
Al
Na
Mg
K
Zn
Pb
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
79300
60100
81100
38200
30900
38600
16000
35000
8600
8200
7500
7700
5300
3200
2800
2300
(6200)
(7300)
(7300)
(1900)
(2200)
(7200)
(2500)
(17300)
(680)
(340)
(690)
(190)
(860)
(240)
(380)
(290)
70500
71900
31700
23800
24500
29400
13600
12400
5100
8000
5100
7500
1400
3200
1800
2100
(2100)
(1600)
(3600)
(7700)
(830)
(660)
(380)
(750)
(170)
(290)
(340)
(340)
(140)
(140)
(510)
(320)
73400
74800
33700
23200
24100
29300
12400
11800
5600
8400
4900
7700
1200
3200
1500
2100
(4300)
(3700)
(1400)
(8400)
(1300)
(1000)
(220)
(650)
(270)
(290)
(310)
(320)
(300)
(270)
(430)
(250)
68700
61200
37400
26500
27000
30000
15900
10000
4900
11400
5500
8600
1700
3600
1600
2100
(7000)
(11900)
(220)
(9100)
(1000)
(1000)
(4000)
(2100)
(1500)
(3100)
(890)
(2100)
(150)
(320)
(360)
(370)
66800
69800
39300
41100
NA
NA
NA
NA
7300
11700
5600
7200
3000
5800
1400
2400
(9900)
(8600)
(7400)
(8100)
(730)
(1400)
(320)
(420)
(350)
(1200)
(240)
(350)
Minor Metals
Cu
Mn
Ba
Cr
Ni
Cd
As
Ag
Se
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
BA
CA
830
1200
760
550
630
430
70.2
77.9
100
45.0
27.1
33.3
21.0
24.3
<0.1
<2.2
<0.2
<2.2
(250)
(400)
(60)
(60)
(70)
(30)
(10.8)
(3.8)
(10.0)
(3.9)
(6.1)
(1.6)
(4.7)
(4.2)
720
720
530
520
250
350
70.8
86.0
30.0
55.0
10.3
33.5
19.8
47.7
<2.2
<2.2
<2.2
<2.2
(260)
(80)
(30)
(20)
(20)
(20)
Trace
(15.1)
(15.1)
(4.9)
(11.0)
(1.1)
(1.4)
(11.1)
(13.6)
650
810
550
530
280
370
Metals
75.1
80.6
34.0
45.0
11.5
35.2
<4.1
12.2
<2.2
<2.2
<2.2
<2.2
(170)
(100)
(40)
(20)
(40)
(40)
(6.4)
(3.4)
(5.0)
(7.0)
(1.8)
(2.4)
(0.7)
690
740
570
550
420
600
86.8
110
26.0
40.0
8.9
32.9
<4.1
5.5
<2.2
<2.2
<2.2
<2.2
(120)
(150)
(30)
(50)
(50)
(70)
(24.5)
(35.3)
(4.2)
(2.9)
(1.3)
(1.1)
(1.4)
510
500
500
550
380
520
77.2
74.7
120
35.2
11.9
35.2
4.9
8.9
<2.2
<2.2
<2.2
<2.2
(180)
(160)
(100)
(70)
(140)
(120)
(7.0)
(6.8)
(15.4)
(10.1)
(2.1)
(10.1)
(2.6)
(3.1)
Table 10, Mean and Std. Dev. Concentration of
Metals Measured in Control Blocks
Analyte Concentration(g/g)
Ag
Al
As
Ba
Ca
Cd
Cr
Cu
Fe
K
Mg
Mn
Na
Ni
Pb
Se
Zn
<1.1
32300(11100)
<5
190 (50)
23000 (6900)
<10
7.8 (1.3)
24 (12)
14500 (810)
5800 (1900)
1100(380)
170 (10)
28900 (3200)
8.6(2.1)
<0.25
<2.2
56 (13)
chemistry alterations that may occur as a
result of weathering.
To date, no adverse environmental or
structural impacts have been observed in
the boathouse due to the use of MSW
combustor ash as an aggregate substitute
in the cement blocks.
The full report was submitted in
fulfilment of Cooperative Agreement No.
CR818172-01-0, by the Research Foun-
dation of the State University of New York
under the sponsorship of the U.S. Envi-
ronmental Protection Agency.
-------
Frank J. Roethel and Vincent T. Breslin are with the Waste Management
Institute, a division of the Marine Sciences Research Center, State University
of New York, Stony Brook, NY 11794.
Diana R. Kirk is the EPA Project Officer (see below).
The complete report, entitled "Municipal Solid Waste (MSW) CombustorAsh
Demonstration Program "The Boathouse" (Order No. PB95-260279; Cost:
$19.50, 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 Officer can be contacted at:
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection Agency
National Risk Management Research Laboratory (G-72)
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-95/129
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