Asbestos in the Water Supplies of
the Ten Regional Cities
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Dr. R.J. Carton
Environmental Protection Agency
Office of Toxic Substances
Washington, D.C. 20460
Contract 68-01-2690
Asbestos in the Water Supplies of
the Ten Regional Cities
Date: 22 APril 1976
MA Number: MA 4200
Copy /? of M
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2820 SOUTH MICHIGAN AVENUE CHICAGO, ILLINOIS 60616
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-Asbestos in the Water Supplies of
the Ten Regional Cities
Summary
Discussion
Conclusions
Appendix 1 Boston
Appendix 2 New York
Appendix 3 Philadelphia
Appendix 4 Atlanta
Appendix 5 Chicago
Appendix 6 Dallas
Appendix 7 Kansas City
Appendix 8 Denver
Appendix 9 San Francisco
Appendix 10 Seattle
Appendix 11 List of Sample Sites
Appendix 12 Analytical Methodology
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City of Boston
The Boston water supply originates from two main sources - the
Quabbin watershed and the Wachusett watershed - located in Central Massachu-
setts and is fed to the city by a series of aqueducts. The city was visited on two
occasions, 25 July 1975 and 17 October 1975 when samples were collected at
Norumbego treatment station situated on the Hultman aqueduct. In March 1976
additional samples were received from the city of Boston water department.
These samples were two raw samples taken at the outlets of Quabbin and
Wachusett Reservoirs, a raw sample taken at the Norumbego treatment station
and a chlorinated sample taken at Newton pumping station.
The results of the analyses for asbestiform minerals are tabu-
lated. The data for Norumbego on 7/25/75 at first seem anomalous. The
detection of amphibole in the chlorinated water only is not at present understood.
The amphibole type present could be amosite or crocidolite. (Na is not readily
detectable by the EDXRA (energy dispersive x-ray analysis) system and some
crocidolite standards have failed to give a detectable peak.) The possibility of
amphibole contamination, such as from a gasket or insulation cannot be entirely
ruled out. In connection with a different contract in which considerable amounts
of chrysotile were detected in a sample the source of this asbestos was traced
to a deteriorating gasket in a pump in the treatment plant of that city.
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Sample location and type
Norumbego station
Raw
City of Boston
Date
7 25 75
Chlorinated 7 25 75
Norumbego station
Raw 10 17 75
Chlorinated 10 17 75
Quabbin
Wachusett
Norumbego
Newton
Raw
Raw
Raw
March 76
March 76
March 76
Chlorinated March 76
F.p.l.1 (xlO6)
BDL (0.28)
6.7 (C)R
1.4 (A)2
4.4 (C)R
7.5 (C)
10 (C)
8.1 (C)R
BDL R (0.126)
BDL (0.126)
BDL (0.126)
BDL (0.126)
BDL (0.126)
[i g/litre
0.069
25.2
35.7
1.43
33.8
22.6
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Sample location and type
Queen Lane Raw
City of Philadelphia
Date
5 1475
Queen Lane Finished 5 14 75
Belmont
Raw
Torresdale
5 1475
Belmont Finished 5 14 75
Xorresdale Raw 5 14 75
Finished 5 14 75
70 (C)2
BDL^R2 (1/0)
BDL3 (0.13)
11 (C) R2
24 (C)2
84 (C) R
6.7 (A) R2
0.75 (C}2
BDL3 (2.5)
200 (C)2 R
17 (Q2
4
Hg/litre
3.89
0.227
31.9
12.9
0.322
0.007
1.233
0.581
0.301
1) F.p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Relicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Sample location and type
Marston Conduit 20
Raw
Marston Conduit 30
Finished
Moffat
Moffat
Marston
Marston
Moffat
Moffat
Moffat
Raw
Finished
Raw
Finished
blend
Raw
City of Denver
Date
2 2675
2 2675
2 2675
2 2675
9 15 75
9 15 75
9 15 75
Finished No. 2 91575
Finished No. 3 91575
1 6
F.p.l. (xlO )
BDL (0.25)
0.22(A) R(5)
BDL (0.25)
0.056(A) R(5)
BDL (0.25)
BDL R (0.1)
BDL (0.25)
BDL R (0.05)
1.5(5) (C)
BDL (0.52)
BDL (0.50)
BDL (0.50)
BDL (0.50)
H.g/litre
.491
.333
.648
1) F.p.l. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Standard Chrysotile Dispersion
/»
No. No. of observations Fibers/litre (xlO ) Relative Std.dev. (%)
la 39 33.5 9.88
lb 9 34.3 ig.08
lc 5 31.7 38
Id 15 25.7 8.96
le 15 27.4 6.85
If 5 2.38 11.09
lg 5 0.36 48.6
Notes
Runs la - lc freshly prepared dispersion, results of 3 different observers.
la = 39 observations, 3 grid squares on each of 13 different grids
lb = 9 observations, 9 grid squares from 5 different grids
lc = 5 observations, 5 grid squares from 1 grid
Id and le = 2nd and 3rd preparation from standard after manual agitation to
redisperse, 3 grid squares from 5 grids, observer of la
If = suspension of la - le, diluted 10:1, 1 grid square from 5 grids, observer
of 1 a
lg = as If, but diluted 100:1
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Asbestos in the Water Supplies of the Ten Regional Cities
Summary As part of a program to determine the impact of point
and non-point sources on waterborne levels of asbestos, samples of
raw and finished wafer from the ten cities housing regional head-
quarters of the Environmental Protection Agency have been examined.
These cities are Boston, New York, Philadelphia, Atlanta, Chicago,
Dallas, Kansas City, Denver, San Francisco and Seattle.
The results of this examination show that while New
York, Chicago, Dallas, Kansas City and Denver are essentially free
of asbestos, asbestiform fibers have been detected at Boston,
Philadelphia, Atlanta and Seattle and the potential exists for asbestos
contamination in the water supply of San Francisco.
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Introduction
The Office of Toxic Substances of the Environmental Protection
Agency has sponsored a nationwide survey to determine the impact of point and
non-point sources on waterborne levels of asbestos. This survey covers both
.natural sites, in which asbestos.bearing rocks are prevalent, and man-made
sources. Additionally, it provides for sampling water supplies in a number of
cities and towns. A listing of these sites is given in Appendix 11 accompanying
this report.
This report records the results of the analysis of water from
the ten major regional cities, headquarters of the EPA regional offices.
Sampling and Analysis Methods (See Appendix 12)
Aliquots of the water were vacuum filtered through 47 mm dia
JMillipore 0.45 (im pore size filters. This filter was then prepared for examina-
tion on the transmission electron microscope by the direct transfer method.
Nylon support grids were used to minimize background signals during X-ray
analysis in EMMA-4, the combined electron microscope microanalyzer.
Wherever practicable samples for analysis were filtered directly on site.
Exceptions to this were the cities of Chicago, Denver and Seattle.
Results
Appendices 1 -10, numbered to correspond to the EPA region
number, each describe the sampling locations and conditions, tabulate the
results obtained and briefly discuss the results.
General Discussion
Although asbestos fibers have been detected in the water sources
and supplies of some major cities, in almost all cases the fiber sizes have been
extremely small. Indeed in most cases the mean fiber length noted is of the
order of 1.5 to 2 micrometers with some instances of submicrometer mean
lengths observed. The most marked exceptions to this generality occur in
samples from Boston with mean lengths of 5.4 nm and 9.6 pm but here, other
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anomalies in the data have led to the postulation of a proximal source for the
asbestos, such as a deteriorating gasket or damaged transite pipe.
The role of climatic changes appears to have been demonstrated
in Atlanta and Philadelphia where samples associated with high river flow rates
have shown an increased asbestos count. Climate might also be expected to
influence possible asbestos levels in the San Francisco area since the reservoirs
of that city which showed an asbestos content (principally Calaveras and Lower
Crystal Springs) receive water from the Hetch-Hetchy aqueduct during periods
of low precipitation in their neighboring watersheds and thus are not contributing
to the water supply at that time.
In all instances where asbestos has been detected the predominant
asbestos type has been chrysotile and, again with the exception of one analysis
from one Boston sample asbestiform amphibole has not been observed other
than associated with chrysotile.
It is necessary to inject a note of caution on the significance of
the mass per litre data. This data is derived mathematically from the dimen-
sions of the individual fibers, assuming a density of 2.3 g/cc for chrysotile
and 3.3 g/cc for amphibole and a square cross section. Apart from the geo-
metric limitations referred to in Appendix 12 it should be borne in mind that
the occurrence of a single large, or, more particularlyswide fiber will
severely skew the data to an unrealistically high figure.
Conclusions
Although asbestos fibers have been detected in the water supplies
and sources of five of the ten regional cities Boston, Philadelphia, Atlanta,
San Francisco and Seattle the fiber size observed is generally very small,
averaging approximately 1-3 pm long. The remaining five cities, New York,
Chicago, Dallas, Kansas City and Denver showed no asbestos levels above
background.
Some evidence exists for seasonal variations in the observed levels.
It has not been established whether these levels are attributable to natural or
point sources.
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Appendix 1 Boston
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City of Boston
The Boston water supply originates from two main sources - the
Quabbin watershed and the Wachusett watershed - located in Central Massachu-
setts and is fed to the city by a series of aqueducts. The city was visited on two
occasions, 25 July 1975 and 17 October 1975 when samples were collected at
Weston reservoir, one of the small overflow reservoirs on the aqueduct system.
In March 1976 additional samples were received from the city of Boston water
department. These samples were two raw samples taken at the outlets of
Quabbin and Wachusett Reservoirs, a raw sample taken at Norumbega reservoir
(similar to Weston reservoir but situated on the Hultman aqueduct) and a chlo-
rinated (presumably finished) sample taken at Newton pumping station.
The results of the analyses for asbestiform minerals are tabulated.
The data for Weston on 7/25/75 at first seem anomalous. The detection of
amphibole in the finished water only is not at present understood. The amphibole
type present could be amosite or crocidolite. (Na is not readily detectable by
the EDXRA (energy dispersive x-ray analysis) system and some crocidolite
standards have failed to give a detectable peak.) The possibility of amphibole
contamination, such as from a gasket or insulation cannot be entirely ruled out.
In connection with a different contract in which considerable amounts of chryso-
tile were detected in a sample the source of this asbestos was traced to a
deteriorating gasket in a pump in the treatment plant of that city.
It should be noted that the March 1976 samples do not duplicate
the 1975 samples in that Norumbego reservoir is not located on the same
aqueduct as Weston and the advisability of additional sampling on both aqueducts
should be considered.
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Sample location and type
Weston Reservoir
Raw
Finished
Weston Reservoir
Raw
Finished
Quabbin
Wachusett
Norumbego
Newton
Finished
Finished
Finished
Finished
City of Boston
Date
725 75
7 25 75
10 17 75
10 17 75
March 76
March 76
March 76
March 76
F.p.l.1 (xlO6)
BDL (0.28)
6.7 (C)R
1.4 (A)2
4.4 (C)R
7.5 (C)
10 (C)
8.1 (C)R
BDL R (0.126)
BDL (0.126)
BDL (0.126)
BDL (0.126)
BDL (0.126)
\i g/litre
0.069
25.2
35.7
1.43
33.8
22.6
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 2 New York
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City of New York
The city of New York water supply is derived from two main
systems - the Catskill-Delaware system which is fed to the Hillview Reservoir
in Yonkers and the lower level Croton system. The water is treated with
CuSO. for algae control, chlorinated to maintain a level of 0.8-1.0 ppm free
4
chlorine and fluorinated. pH is adjusted to 6.9-7.0 by the addition of NaOH.
The water was grab sampled at 3 reservoirs on 2 separate
occasions, 11 August and 22 October 1975. Raw water was sampled at the
Hillview, Jerome Park and Central Park reservoirs and finished water at the
Hillview and Central Park reservoirs. At Hillview, both the Catskill source
and Delaware source raw waters were sampled.
No asbestiform minerals were detected in any New York City
water samples, either in the raw water or in the finished product.
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City of New York
Sample location and type Date
Jerome Park Reservoir
Raw 8 11 75
Central Park Reservoir
Raw 8 11 75
Finished 8 11 75
Hillview Reservoir
Raw 8 11 75
Finished 8 11 75
Jerome Park Reservoir
Raw 10 22 75
Finished 10 22 75
Central Park Reservoir
Raw 10 22 75
Finished 10 22 75
Hillview Res(Catskill
source) Raw 10 22 75
Hillview Res (Delaware
source) Raw 10 22 75
Hillview Res Finished 10 22 75
F.p.l.1 (xlO6)
BDL (0.18)
BDL (0.21)
BDL (0.13)
BDL (0.36)
BDL (0.18)
BDL (0.25)
BDL (0.25)
BDL (0.25)
BDL (0.25)
BDL (0.25)
BDL (0.25)
BDL (0.25)
g/litre
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole
3) BDL = Below detection limit; number in parentheses = detection limit,
f.p.l.
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 3 Philadelphia
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City of Philadelphia
The city of Philadelphia draws its water supply from two main
sources, the Schuylkill River and the Delaware River via 3 plants - Queen Lane
and Belmont on the Schuylkill and Torresdale on the Delaware. The city was
visited on 3 occasions - 14 May 1975, 27 October 1975 and 1 and 2 April 1976.
On flie first two occasions grab samples were taken at all 3 plants. On the
third visit both grab and integrated samples were taken. Grab samples were
also collected at points on the Schuylkill River and Wissahickon Creek - a
principal tributary of the Schuylkill having its confluence with the Schuylkill just
above the Queen Lane intake. Samples which had been collected on the Delaware
during boat surveys by the Philadelphia water department were also received
on the third visit. Only the data for the water supply samples are presented in
this report. Data for the river samples will be presented in a later report.
The results of the analyses are presented in the table following
this report. It will be noted that some wide variations occur between replicate
samples. One explanation for this lies in the appearance of the asbestos observed
which both analysts described as occurring in clumps. Such clumping generally
makes quantitation more difficult and less objective e. g. it is difficult on
occasion to decide whether a clumped fiber is truly one fiber or an aggregate
of several; additionally, other adhering particulates may obscure fibers or
portions of fibers.
Despite these difficulties there is no doubt that asbestos fibers
are present in the raw water intakes of Queen Lane and Belmont and that a
portion of these can pass through the Belmont filtration and be released into the
water supply. The situation at Torresdale is less clear. We believe the high
counts observed at Torresdale may well represent isolated events which are
not reflected in the later, integrated samples.
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Another confusing factor in the Philadelphia situation is the
weather effect. On both the 1975 visits the rivers were running above their
long term monthly averages as shown in the following table.
Daily Average Flow (cfs)
Date Delaware River at Trenton Schuylkill River at Philadelphia
51075 21,400 3,860
51175 18,800 3,570
5 12 75 17,000 3,360
51375 17,900 4,310
5 1475 24.700 4.720
51575 26,800 3,830
51675 25,900 4,510
Long term May avg. 14,600 23,390
102475 26,400 4,860
102575 22,600 4,370
102675 20,100 4,030
10 27 75 18.000 3.670
102875 16,100 3,280
102975 15,100 3,000
103075 13,700 2,770
Long term Oct avg 4,200 1,425
The April 1976 visit was marked by severe thunderstorms and very heavy rain
on the night before sampling. The decision was therefore made to integrate the
samples over two 12 hour periods instead of one 24 hour period in order to
determine whether any weather effects could be detected, and indeed we do see
an increase at all three intakes during the second 12 hour session. This is
believed to indicate transport of material from upstream shore line asbestos
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deposits which are more severely eroded during adverse weather conditions.
The exact location of these deposits is not at present identified.
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Sample location and type
Queen Lane Raw
City of Philadelphia
Date
5 1475
Queen Lane Finished 5 14 75
Belmont
Raw
5 1475
Belmont Finished 5 14 75
Torresdale Raw 5 14 75
Torresdale Finished 5 14 75
(C)2
L3R2 (1.0)
BDL3 (0.13)
70 (C)2
BDL
(C)R
24 (C)
6.7 (A) R*
0.75 (CJ2
BDL3 (2.5)
200 (C)2
17 2
4(C)2
Hg/litre
3.89
0.227
31.9
12.9
0.322
0.007
1.233
0.581
0.301
1) F.p..l. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Relicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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City of Philadelphia
1 6
Sample location and type Date F.p.l. frlO ) tig/litre
Queen Lane Raw 10 27 75 BDL3 (0.13)
100 (C)R2 210.54
Queen Lane Finished 10 27 75 BDL3
Belmont Raw 10 27 75 230 (C)2 2.6
Belmont Finished 10 27 75 130 (C)2
26(C)R2 0.588
Torresdale Raw 10 27 75 160 (C)2 3.63
Torresdale Finished 10 27 75 16 (C)2 0.259
60 (C) R2 0.016
1) F.p.l. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Philadelphia Integrated samples
Sample location and type
Queen Lane
Queen Lane
Belmont
Belmont
Torresdale
Torresdale
Queen Lane
Queen Lane
Belmont
Belmont
Torresdale
Torresdale
Raw
Finished
Raw
Finished
Raw
Finished
Raw
Finished
Raw
Finished
Raw
Finished
Date
4 176
4176
4 176
4176
4 1 76
4176
4276
4276
4276
42 76
4276
42 76
24
BDL (0.13)
7.7 (C)2
1.1 (C)2
BDL3 (0.25)
BDL3 (0.13)
120 (C)2
BDL3 (0.13)
50 (C)2
4.3 (C)2
0.745 (C)2
1.0 (C)2
Hg/litre
0.501
0.016
0.075
22.423
1.391
0.213
0.012
0.02
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 4 Atlanta
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City of Atlanta
Atlanta draws its water from the Chattahoochee River which rises
in the hills of White County and flows south to join the Apalachicola and from
thence into the Gulf of Mexico.
The city of Atlanta water supply was sampled on two occasions,
3 April 1975 and 28 November 1975. On each visit a sample of the raw water
and a sample of the finished water was obtained from the Atlanta water works
quality control control center located in Northwest Atlanta. Two additional
samples taken by the Atlanta water department in March 1976 were also obtained.
The results of the analysis for asbestiform minerals are pre-
sented in the accompanying table. The presence of chrysotile asbestos during
the April sample, its absence in November and its recurrence in March of 1976
may reflect seasonal variations. It was noted during the April 1975 visit that
sampling had followed a violent thunderstorm with tornado watch the previous
evening and that the Chattahoochee River was rising due to torrential rains:
indeed the flow rate, recorded at 11,300 c.f. s. was almost 2-1/2 times the
1974 average of 4800 c.f.s.
At the time of sampling in March 1976 the river was again
reported as running at a high level.
At such periods of high flow rate natural erosion processes are
accelerated and settled detritus may be reentrained. Additionally shore line
deposits, either natural or industrial may become submerged and eroded which
normally are unaffected by the river flow. We believe, therefore, that the
asbestos content of Atlanta raw water may be related to climatological conditions.
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Sample location and type
City of Atlanta
Date
Water Quality Control Center
Raw 4 3 75
Water Quality Control Center
Finished 4 3 75
Finished 4 3 75
Water Quality Control Center
Raw 11 28 75
Finished 11 28 75
Water Quality Control Center
Raw March 76
Finished March 76
8.4 (C)*
12 (C)
11 (C) R
BDL (0.5)
BDL (0.12)
36 (C)
BDL
(0.12)
Eg/litre
0.119
0.574
0.193
0.256
1) F.p.l. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 5 Chicago
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City of Chicago
The city of Chicago draws its water supply from Lake Michigan
via a series of offshore cribs located approximately 1 mile out in the lake. The
water supply was sampled by Chicago water department personnel on March 27,
1975, and two samples, identified as "Raw Crib" and "Outlets" were brought
the same day to the Chicago laboratory of Walter C. McCrone Associates, Inc.,
where they were immediately filtered.
No asbestiform minerals were detected in either the raw or the
finished water.
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City of Chicago
1 6
Sample location and type Date F.p.l. (xlO ) tig/litre
Raw Crib 3 27 75 DDL (0.25)
Outlets 32775 BDL (0.25)
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 6 Dallas
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City of Dallas
Samples of the city of Dallas water supply were obtained from
EPA Region 6 personnel (F. Warren Norris, Jr., Water Division), and
were filtered at McCrone Associates on receipt during March 1975. The
samples were identified by EPA codes as 10841-Raw water; and 10842-
Finished water.
No asbestiform minerals were detected in either sample.
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City of Dallas
l fi
Sample location and type Date F.p.l. (xlO ) tig/litre
10841 Raw March 1975 BDL (0.25)
10842 Finished March 1975 BDL (0.25)
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 7 Kansas City
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Kansas City
Metropolitan Kansas City has three water treatment plants
serving Kansas City, Kansas; Johnson County, Kansas; and Kansas City,
Missouri. All three water treatment plants were visited on September 17,
1975.
The Johnson County plant supplies water to purchasers in the
communities neighboring Kansas City, Kansas on the south. Water from the
Kansas River seeps into 21 wells located along the shore. It is pumped from
these wells into the water treatment plant for processing. Samples were obtained
from the Kansas River at the wells and also from the treated water tap at the
plant.
Both Kansas City, Kansas and Kansas City, Missouri draw water
from the Missouri River near treatment plants just a few miles from each other.
Raw and finished water were obtained from each of these plants.
No asbestiform minerals were detected in either the raw or the
finished water from any of the three Kansas City water treatment plants.
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Kansas City
1 6
Sample location and type Date F.p.l. (xlO ) tig/litre
Johnson County Raw 9 17 75 BDL (2.1 )
Finished 9 17 75 BDL (0.48)
Kansas City, Missouri
Raw 9 17 75 BDL (5.7 )
Finished 9 17 75 BDL (0.41)
Kansas City, Kansas
Raw 9 17 75 BDL (2.1 )
Finished 9 17 75 BDL (0.55)
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 8 Denver
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City of Denver
The city of Denver has two water treatment plants deriving
their water from reservoirs in the mountains. The plants are located at
Marston, in S. W. Denver and Moffat in N.W. Denver. Samples were obtained
at these plants on February 26, 1975, and September 1975.
Reference to the analysis results in the accompanying table shows
that low levels of fibrous amphibole were detected by one analyst in both the raw
and the finished water of Marston plant sampled on February 2. To put this
into perspective, however, it should be noted that these data correspond to
only 2 fibers observed in the raw water sample and 1 fiber in the finished
sample in 10 electron microscope grid squares - a level which could be back-
ground contamination. Similarly the chrysotile reported for Marston Raw on
September 15th corresponds to the observation of 3 fibers in 40 grid squares.
We believe, therefore, that the Denver water supply system is
free of asbestos.
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Sample location and type
Marston Conduit 20
Raw
Marston Conduit 30
Finished
Moffat
Moffat
Marston
Marston
Moffat
Moffat
Moffat
Raw
Finished
Raw
Finished
blend
Raw
City of Denver
Date
22675
2 26 75
2 26 75
2 26 75
9 15 75
9 15 75
9 15 75
Finished No. 2 91575
Finished No. 3 91575
F.p.l. (xlO6)
BDL (0.25)
0.22(A) R(5)
BDL (0.25)
0.056(A) R(5)
BDL (0.25)
BDL R (0.1)
BDL (0.25)
BDL R (0. 05)
1.5(5)
BDL (0.52)
BDL (0.50)
BDL (0.50)
BDL (0.50)
H g/litre
.491
.333
.648
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 9 San Francisco
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City of San Francisco
The San Francisco Water System is extremely complex,
deriving its main feed from the Yosemite Mountains some 100-150 miles east
of the city. From the Yosemites the water is fed via tunnels and pipes (The
Hetch-Hetchy aqueduct) to a number of holding reservoirs which are also fed
by local run off. The map accompanying this report shows, in part, the
complexity of the system. A "short narrative" (some 22 pages and 16 pages
of Appendices) describing the San Francisco water suppling system is available
from the San Francisco Water Department.
The water system was sampled on two occasions, 5 March 1975
and September 10 and 12, 1975 when the following samples were taken.
March 5 Alameda East Portal ("Terminus" of the Hetch-Hetchy
aqueduct.)
This water has been chlorinated and is regarded
as "finished" water. No treatment other than
chlorination is applied.
Calaveras Reservoir
Surface water sampled approximately 50 yards
from boathouse
San Antonio Reservoir
Surface water sampled at boathouse
Lower Crystal Springs Reservoir
Surface water sampled at shore line - rock
samples also collected - bedrock extremely
friable
San Andreas Reservoir
Faucet on side of chlorination plant -"raw water"
San Andreas filtration plant, outlet no. 1, "finished water"
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Pilarcitos Reservoir
Surface water
September 10 Alameda East Portal ("Terminus" of the Hetch-Hetchy
aqueduct.)
This water has been chlorinated and is regarded
as "finished" water. No treatment other than
chlorination is applied.
Calaveras Reservoir
San Antonio Reservoir
Sunol filtration
San Antonio treated
Crystal Springs
"Raw water"
Crystal Springs
"Finished" - chlorination only
San Andreas Reservoir
San Andreas filtration plant, outlet no. 1
"Finished" water
San Francisco tap water - Airport Holiday Inn
September 12 Mocassin Reservoir - about 100 miles east of San
Francisco
During analysis of the first batch of samples it became apparent
that sample preparation problems were being experienced. The data reported
for these samples, therefore, is generally that obtained by Murchio.
Sampling during the second visit was carried out by a different
sampling team and also under a different guide, thus there are some differences
in location at the reservoirs sampled. The most noticeable difference in
results between the two samplings is in the Lower Crystal Springs Reservoir
c
samples where 620 x 10 chrysotile fibers were found on the first visit and
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none on the second visit. We believe this may be explained by the different
locations at which the samples were taken. It was noted in the trip report for
the first visit that the bedrock adjacent to the sampling location is extremely
friable and samples of this rock were taken. These samples did indeed turn
out to have a large serpentine content (determined by light microscopy) and the
rock could be powdered between the fingers. It is therefore not surprising that
the chrysotile content of the first sample is high. It might also not be unexpected
that a sampling point some miles distant from the first should show a com-
pletely different picture. This highlights the problem of trying to characterize
a system as complex as that of San Francisco which could well merit a major
study of its own. An additional explanation of differences between the March
and September samples may be found in the San Francisco Water Department
booklet which, in talking of the Crystal Springs, San Andreas, Pilarcitos
section says .... "Historically this has been a problem water due to high tur-
bidity during the winter months ..." thus seasonal variation may also be a
factor.
We believe the San Francisco situation may best be summarized
as follows:
1) Water from the Hetch-Hetchy aqueduct entering the
San Francisco water system (at Alameda East Portal)
is free of asbestos.
2) The potential for contamination of the San Francisco
water system by asbestos - both serpentine and
amphibole - exists due to natural sources in certain
of the holding reservoirs, principally Crystal Springs
and Calaveras and to a lesser extent San Antonio and
San Andreas.
3) These natural sources may be isolated rock outcrops
whose total impact on a large reservoir (e. g. Crystal
Springs holds 22,580 x 10 gallons) may not be signi-
ficant.
/
4) No evidence has been found of asbestos in any of the
finished waters examined.
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GOLDEN
UC.fOWJI UXOLlt T«M«» »
\ CM 100.000 *
\ CM«IM
STORAGE REEERVCWS
BISTRIBUIIN5 RESERVOfl
SPARLMG METERS
a TANK ELEVATIONS CITY BASE
BAY DIVISION STRUCTURES U.S.G.S.
8.74 =__. U.S.G.S.
,'^toijj^ «.>« »«' ,
i ^SSWSWWIfllR'M."*"*11
SUPERSEDES-X-838-1
ORIGINAL- Jonuory-1949
REVISED-JULY 1973
SAN FRANCISCO WATER DEPARTMENT
X-838-C
-------
City of San Francisco
1 fi
Sample location and type Date F.p.l. (xlO )
Alameda East Portal
Finished
Calaveras Reservoir
Raw
San Antonio Reservoir
Raw
Crystal Springs Reservoir
Raw
3 5 75
3 5 75
3 5 75
3 5 75
San Andreas Reservoir
Raw
San Andreas Outlet No. 1
Finished
Pilarcitos Reservoir
Raw
3 5 75
3 5 75
3 5 75
6DL (0.22)
45 (A) , 240(C)
0.56(A)5, 0.56(C)5
4.3(A), 180(C)
1.7(A)? 71(C)R
4.1(A)
6DL (0.05)
BDL (2.5)
ng/litre
39.019 A,
1. 405 C
0.33A,
0.13C
0.14 A,
141 C
0.341 A,
1.385 C
6.74 A
1) F.p.l. = fibers per litre
2) C = Chrysotile; A=Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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City of San Francisco
1 6
Sample location and type Date F.p.l. (xlO )
Alameda East Portal
Finished 9 10 75
Calaveras Reservoir
Raw 9 10 75
San Antonio Reservoir
Raw 9 10 75
Sunol Filtration ( San
Antonio finished) 9 10 75
Crystal Springs Reservoir
Raw 9 10 75
Crystal Springs Reservoir
Finished 9 10 75
San Andreas Reservoir
Raw 9 10 75
San Adnreas Outlet No. 1
Finished 9 10 75
San Francisco tap water
Finished 9 10 75
Mocassin Reservoir
Raw 9 12 75
BDL (0.43)
2.6 (C)5
15 (C) R
BDL (0.55)
BDL (0.31)
BDL (0.48)
BDL (0.52)
BDL (0.52)
BDL (0.55)
BDL (0.32)
1. 6 (C)1
UgAitre
0.214
0.143
0.04
1) F.p..l. = fibers per litre
2) C = Chrysotile; A = Amphibole; R = Replicate analysis
3) BDL = Below detection limit; number inparentheses = detection limit
4) n.d. = none detected
5) Less than 5 fibers detected
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Appendix 10 Seattle
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City of Seattle
Only 1 sample from the city of Seattle has been examined. This
sample came from the Tolt Reservoir and is therefore raw water. The only
further treatment to which this water is subjected prior to passing into the
distribution system is chlorination. The sample should therefore be
representative also of the finished product.
The "pedigree" of the sample is as follows:
EPA Region 10 Drinking Water Programs Branch is actively
conducting a survey program in their region which includes the Seattle
water supply. Jack Murchio, a consultant on this project is also associated
with the Seattle project and permission was received from EPA region 10 for
the transfer of this sample from their project. The sample is part of a
limited "round robin" series and had been analyzed by two other laboratories
as well as by Murchio.
The data presented herein is that of both McCrone Associates
and of Murchio, the latter identified by the final letter 'M1. The samples
designated DM are duplicates run at McCrone Associates on the actual filter
analyzed by Murchio. It will be noted that Murchio reports both amphibole
fi fi
and chrysotile fibers present at levels of 1.9 x 10 and 1.5 x 10 , respec-
tively, whereas McCrone finds both below the limit of detection. Attention
is drawn, however, to the McCrone descriptions which mention poorly
diffracting fibers resembling chrysotile but with elemental compositions
rich in Al, Si, Ca, Fe and some Mg. A positive identification of these fibers
has not been made and the possibility that they are a fine amphibole in the
Tremolite-Actinolite series cannot be ruled out. We have examined
Murchio's data and consider that his identification of the chrysotile is valid.
We therefore believe that both chrysotile and amphibole asbestos are pre-
sent in Tolt reservoir water.
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For further information on the EPA Region 10 program
contact: Roy Jones, U.S. E.P.A.
Drinking Water Programs Branch
1200 6th Avenue
M/S 429
Seattle, Washington 98101 Phone: 206 442 1223
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City of Seattle
Sample location and type Date
1 fi
F.p.l. (xlO ) tig/litre
Tolt reservoir
'9 875
BDL (0.25)
1.9 (A)M
1.5 (C)M
BDL (0.25) DM
1.21
0.008
1) F. p. 1. = fibers per litre
2) C = Chrysotile; A = Amphibole; M = Murcbio date; DM = Duplicate run at
McCrone Associates on Murcbio sample
(see text)
3) BDL = Below detection limit; number in parentheses = detection limit
4) n. d. = none detected
5) Less than 5 fibers detected
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Appendix 11 List of Sample Sites
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Appendix 11 - Sampling areas and expected source types
Source type
Natural
Mining
Milling
AC Pipe
AC Sheet
Asbestos paper
Sampling area
Montana - Red/Beaver head Rivers
California - Trinity River and various
reservoirs in Northern California
Vermont - Connecticut River
Tennessee-Georgia - Hiwasee, Little
Tennessee and Upper Savannah Rivers
G.A.F. - Vermont
Union Carbide - King City, California
J.M.*-Dennison, Texas
CAPCO - Ragland, Alabama
CAPCO - Van Bur en, Arkansas
Certain Teed - St. Louis, Missouri
Flintkote - Ravenna, Ohio
National Gypsum - New Orleans, Louisiana
G.A.F. -St. Louis, Missouri
J.M.- Nashua, New Hampshire
Nicolet - Ambler, Pennsylvania
J. M. - Tilton, N. H.
J. M. - Pittsburg, California
Armstrong - Fulton, New York
G.A.F. -Erie, Pennsylvania
* J. M. = Johns Manville
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Asbestos paper,
con't. G.A.F. -Whitehall, Pennsylvania
Hollingsworth and Vose - East Walpole,
Massachusetts
Millboard J. M. - Billerica, Massachusetts
Roofing G.A.F. - Erie, Pennsylvania
Tile Armstrong - Kankakee, Illinois
Misc. (frictionmaterials,
tGXtilGS GtC )
' Raybestos Manhattan - Stratford, Connecticut
Raybestos Manhattan - North Charleston, S. C.
Raybestos Manhattan - Marshville, N. C.
Multi product J.M. - Manville, New Jersey
Accessory minerals Morenci Mine - Arizona
Homestake Mine - South Dakota
W.R. Grace - Montana
International Talc Company - New York
Water supplies 10 regional cities
Boston
New York
Philadelphia
Atlanta
Chicago
Dallas
Kansas City
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Water supplies
con't. Denver
San Francisco
Seattle
The following 7 are associated with potential natural sources
lima, Montana
Dillon, Montana
Weaverville, California
Redding, California
Chattanooga, Tennessee
Anderson, South Carolina
Greenville, South Carolina
The following 13 are finished water at plants where city water
is used in processing
St. Louis, Missouri
New Orleans, Louisiana
Erie, Pennsylvania
Pittsburg, California
Lead, South Dakota
Billerica, Massachusetts
Manville, New Jersey
Nashua, New Hampshire
Stratford, Connecticut
North Charleston, South Carolina
Marshville, North Carolina
Kankakee, Illinois
Van Bur en, Arkansas
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Appendix 12 Analytical Methodology
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Appendix 12 Method for Determination of Asbestos
Samples are filtered onto 0.45/xm pore size membrane filters.
Sections of the filter approximately 2-3 mm square are placed face-down on
previously carbon-coated electron microscope grids and the membrane filter is
dissolved, using acetone, in a Soxhlet extractor. Previous work has shown us
that there is very little risk of contamination in transferring the filter on the
electron microscope grid to the Soxhlet extractor. Furthermore, by dissolving
the filter in situ on the grid, the risk of losing portions of the sample is minimal.
Techniques involving transfer of a liquid suspension directly to the electron micro-
scope grid are more subject to error since there is frequently a size separation
as the meniscus of the drying drop recedes.
The sample grids are examined on the electron microscope (JEM 200
or EMMA 4) using a magnification such that the intermediate lens aperture is in
focus in the specimen plane. It is thus possible, by inserting the aperture and
switching to the diffraction position, to obtain a selected area electron diffraction
(SAED) pattern of the fiber with no other adjustments to the microscope. In this
way it is possible to spot check the diffraction pattern of individual fibers very
rapidly.
The length and width of each asbestos fiber is recorded. Interpolation
from intervals scribed on the screen allows an accuracy of measurement on the
screen of approximately +0.05 cm. This corresponds to an accuracy in size measure
ment of about 0.02-0.03 /zm. Measurements of the individual fibers are computer
processed to give listings of the length and width of the fibers, together with a
computed mass of each fiber computed on the basis of density, D, and dimensions,
L and W (D x L x W2). A value of 3.40 is taken as the mean density of grunerite
amphibole fibers. Densities of 2.3 and 3.0 are used for chrysotile and tremolite,
respectively. Because many of the amphiboles are lath-shaped rather than square
s
in cross section, this figure may well be slightly high, since the laths will, in
general, tend to lie flat rather than on edge. There is, however, a finite possi-
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bility that some laths will be on edge and, due to the very small size of many
of the fibers of interest, the approximation to a square fiber will not give more
than a slightly high bias to the mass readings. The program automatically
assigns the longest dimension to the fiber length and excludes all fibers with an
aspect ratio below three.
Also presented in the computer printout are the calculated number
of fibers per unit volume, the calculated mass of fiber per unit volume, the size
distribution of the fibers based on length and width, and the distribution of fibers
by aspect ratio together with the relevant statistical information on these para-
meters.
A sample computer printout is attached.
As mentioned in the first paragraph, losses in a correctly operated
Soxhlet extractor are minimal, but careful control of both heating rate and cooling
rate of the cold finger are required. When these conditions are obtained, and
maintained, estimated losses (based on filtration and examination of the solvent
after several weeks use) are less than 1 fiber per grid processed. Additional
evidence that losses are minimal is provided by examining filter segments which
do not fully cover the grid. These show a clean junction between membrane and
non-membrane area with no evidence of "bleed-off1 of particulates.
The reproducibility of the method is clearly of prime importance.
A report is currently being prepared describing tests performed to assess the
reproducibility,accuracy and statistical validity of the method. The accompanying
table presents part of this data and shows that, for a standard chrysotile dis-
persion, the filtration technique, and the electron microscope preparation method
yield uniform dispersions over the entire filter area and grid area within a
standard deviation of less than 10%. This standard deviation, however, also
includes the variation in the operator's objectivity in deciding whether fiber
bundles are one fiber or a composite of fibers, thus the S.D. of the dispersion
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is probably better than 10%. The standard deviation deteriorates to approximately
20% when 3 operators (using 2 different Soxhlet extractors in different laboratories)
are involved.
The data also show exceptionally good agreement between expected
and observed values when successive dilutions of 10:1 and 100:1 are analyzed,
although with low loadings the standard deviation again increases, as might be
expected - at extreme dilutions clearly one enters the realm of probability statistics
and the chance of finding a fiber in any given grid square predominates.
Errors in estimating the fiber content of real samples generally err
on the low side because of practical difficulties such as fiber overlap - either with
other fibers or with non-fibrous particulates in the sample. Furthermore, the
philosophy has been adopted of only counting fibers which can be positively identi-
fied as asbestos during examination of the sample - it is impractical to photograph
each fiber together with its diffraction pattern for later analysis and measurement.
The possibility exists, therefore, that fibers in the grey area between positive
acceptance and positive rejection as asbestos will be excluded although they might
be asbestiform.
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Standard Chrysotile Dispersion
/»
Run No. No. of observations Fibers/litre (xlO ) Relative Std. dev.
*a 39 33.5 9.88
lb 9 34.3 19.08
!c 5 31.7 38
ld 15 25.7 8.96
!e 15 27.4 6.85
1* 5 2.38 H.09
1 g 5 0.36 48.6
Notes
Runs la - Ic freshly prepared dispersion, results of 3 different observers.
la = 39 observations, 3 grid squares on each of 13 different grids
lb = 9 observations, 9 grid squares from 5 different grids
Ic = 5 observations, 5 grid squares from 1 grid
Id and le = 2nd and 3rd preparation from standard after manual agitation to
redisperse, 3 grid squares from 5 grids, observer of la
If = suspension of la - le, diluted 10:1, 1 grid square from 5 grids, observer
of la
Ig = as If, but diluted 100:1
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SAMPLE
FIBER CONCENTRATION BY NUMBER,PER LITER
FIOER CONCENTPATION BY MASS, PER LITER :
VOLUME FILTERED : 2.7 ML.
GPID SQU/iRES COUNTED . - 16
TOTAL SUCPEHDED COLIDS: 44.000 MG PER LITER
PM = 7.4
0.14E+B9
1272.500 GRAMS*10+-6
DESCRIPTIVE STATISTICS
NO. OBS. = 34
VARIABLE
1 LENGTH
2 WIDTH
3 ASPECT RATIO
4 MASS
MEAN
0.32?71E+01
0.45912E+GO
0.10909E+02
0.30250E+01
VARIANCE
0.54009E+01
0.22Q26E+QO
Q.5612SE-i-G2
0.42L18E+03
STANDARD
DEVIATION
0.23240E+01
0.46932E+00
0.74917E+01
0.20717E+02
STANDARD
ERROR
O.39856E+Q0
0.8Q4S7E-01
0.12S4SE+01
0.3552?E+01
1
2
3
4
SKEUNESS
14010E+01
15926E+01
15959E+01
0.2827-JE+01
0.
0.
0
0.
KURTOSIS
79?31E*CO
16288E+01
2085SE+01
MAX
0.90000E+01
Q.180GQE+01
0.36000E+02
0.96228E+02
niN
0 60000E+00
0.5000CE-01
0.33333E+01
0.12700E-01
0.
0.
o!
RANGE
84000E+01
17560E+01
32667E+02
0.9G215E+02
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SHHPLC
CAMPHIBQLE)
LENGTH
WIDTH
ASPECT
RATIO
MASS
1
2
7
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
1 . 8000
2.2000
3. 4000
3. 0000
9. 0000
1. 4000
2. 0000
2. 0000
2. 4000
4. 0000
4. 0000
2. OCOO
2. 8000
3. 5000
6.0000
0.6000
2. 4000
3. 0000
2. 5000
1 . 8000
2.4300
7. 0000
7. OOBO
2.2600
9. 0000
2. 2000
1.8000
1. 8000
0. 6000
3.50CO
9. eoeo
2.0000
2. 0000
1 . 8000
0. 1009
0. 2080
0. 4000
0. 3000
0.7000
0. 2000
0. 3000
0. 3000
0. 4000
1. 2000
0. 5000
0. 3000
0. 30CO
0. 3000
1. 8000
0. 1000
0. 2000
0. 3000
0 3000
C. 0500
0. 1000
1 . O&OO
1. 3600
0.0800
1. 8000
0. 1000
0. 2COO
0 3000
0. OGOO
0. 6000
1. 0000
0. 6000
0. 1000
0. 1000
18.0900
11. 0000
8. 5000
10. 0000
12.8571
7. 0000
6.6667
6. 6667
6.0000
3.3333
8.0000
6. 6667
9 3333
11. 6667
3.3333
6.0000
12. 0000
10. OCOO
8.3333
36.0000
24. 0006
7. 0000
5. 3846
27. 5000
5. 0000
22. 0000
9.0000
6 06013
7.5600
5.8333
9. OOOO
3. 3333
20. 0000
18. 0000
1.
64.
0.0594
0.2904
1.7952
0.8910
14.5530
0.1848
0.5940
0. 59-10
1.2672
19.60SO
3.3000
0.5940
0.8316
0395
1520
0.0193
0.3168
0.8910
0.7425
0.0148
0.07?2
23.1000
39.0390
0.0465
96.2280
0.0726
0.2376
0 5346
0.0127
4.1580
29.7000
2.3760
0.0660
0.0594
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SAMPLE
LENGTH
DISTRIBUTION BY LENGTH
NUMBER PERCENT
0.0
8.5
1.0
1. 5
2. 0
2. 5
3. 0
3.5
4. 0
4. 5
5. 8
5. 5
6. 0
6.5
7. 0
7. 5
8. 0
8. 5
3.0
0. 5
1. 0
1. 5
2. 0
2. 5
3. 0
3. 5
4. 0
4. 5
5. 0
5. 5
6. 0
6. 5
7. 0
7. 5
8. 0
8. 5
3. 0
3. 5
0
2
1
16
7
3
3
2
0
0
0
1
0
2
0
0
0
3
0
0.00
5. 88
2. 94
23. 41
20.53
8. 82
8. 82
5.88
0. 00
0. 00
0. 00
2. 94
0. 60
5. 88
0. 00
0. 00
0. 30
8. 82
0. 00
CUMUL&TIVC
PERCLMT
0. 00
5.8S
8.82
38. 24
58. 82
67.65
76.47
82.35
82.35
82.35
82.35
85.29
85. 29
91. IS
91. 18
91. 18
91. 18
100.00
100.00
WIDTH
DISTRIBUTION BY WIDTH
NUKBER PERCENT
0. 0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0.8
&. 3
1'. 0
1. 1
2
3
4
5'
1. 6
1. 7
1.8
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
0. 9
1. 0
1. 1
1. 2
1. 3
1. 4
1. 5
1. 6
1. 7
1. 8
1. 9
3
4
3
2
1
3
0
1
0
0
2
0
1
1
0
0
0
0
2
26. 47
11. 76
26. 47
5. 88
2. 94
8. 32
0. 00
2. 34
0. 00
0. CO
5. 88
0. 00
2 94
2. 94
0. 00
6.00
@. 00
0. 00
5. 88
CUMULATIVE
PERCENT
26.47
38.24
64.71
70.59
73.53
82-. 35
82.35
85. 29
85. 29
85.29
31. 18
31. 18
34'. 12
37.06
97. 06
37. 06
37. 06
37.05
102.94
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DISTRIBUTION DY AT.rfTCT RCiTIO
ASPECT RATIO NUMBER PERCENT CUMULATIVE
PERCENT
3 10 23 67.65 67.65
10 20 7 20. 59 88 24
20 30 3 8.8£ 97.06
30 40 1 2. 94 160 OCi
40 50 0 0.00 100.00
50 60 0 0.00 100.00
60 70 0 0.00 100.00
70 80 0 0.00 100.00
80 90 0 0.00 100.00
90 100 0 0.00 100.00
100 110 0 0.00 100.03
110 120 O 0.00 lOO.OO
120 130 O 0.00 100.00
130 140 0 0.00 100 00
140 150 0 O.OO 100.00
150 160 0 0.00 100.00
160 170 0 0.00 100.00
176 IRQ 0 0.00 100.00
18& 196 0 0.00 100.00
190 200 O 0.00 lOO.OO
* OVER 230 0 0.OO 100.00
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