xvEPA
United States Environmental Monitoring Systems EPA/600/4-87-002
Environmental Protection Laboratory January 1987
Agency Research Triangle Park NC 27711
Research and Development
National
Performance Audit
Program
Ambient Air
Audits of Analytical
Proficiency1985
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EPA/600/4-87/002
January 1987
NATIONAL PERFORMANCE AUDIT PROGRAM
AMBIENT AIR AUDITS OF ANALYTICAL PROFICIENCY
-1985-
by
Blaine F. Parr, Robert L. Lampe, Gregory Pratt,
Oscar L. Dowler and William J. Mitchell
Quality Assurance Division
Environmental Monitoring Systems Laboratory
Research Triangle Park, North Carolina 27711
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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NOTICE
This document has been reviewed in accordance with U.S. Environmental
Protection Agency policy and approved for publication. Mention of trade
names or commercial products does not constitute endorsement or recommenda-
tion for use.
ii
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ABSTRACT
This report presents the results of the U.S. Environmental Protection
Agency's 1984 National Ambient Air Performance Audit Program by pollutant
and_by analytical method. Semiannual audits were conduced for Pb, NC>3~ and
S0^~ on filter strips and acid rain. Annual audits were conducted for SC^
(bubbler), N02 (bubbler), CO and high-volume sampler flow rate. Continuous
SC>2 monitors were audited throughout the year, with no monitor being audited
more than once. Approximately 33 laboratories participated in each semi-
annual acid rain audit. Twelve laboratories participated in the S02 bubbler
audit, and 18 in the _M>2 audit. Approximately 54 laboratories participated
in each NO^" and S0^~ audit and approximately 105 laboratories in each Pb
audit. Three hundred and twenty-five CO monitors, 257 S02 monitors and
1336 high volume flow samplers were also audited. The results for each
audit are presented in tabular form for each concentration level. The
overall performance for all participants for each audit conducted since the
beginning of the program is also illustrated in a series of figures. For the
most part the results of the 1985 audits are essentially unchanged from the
1983 and 1984 audits.
iii
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CONTENTS
Page
Abstract ill
Tables v
Figures vii
Acknowledgments viii
1. Introduction 1
2. Summary and Conclusions 3
3. Audit Materials 4
4. Audit Results 7
References 12
Tables 13
Figures 39
iv
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TABLES
Number Page
1 Agency Participation 13
2 Audit Results for Manual Sulfur Dioxide 14
3 Results for the Pararosaniline Method .... 15
4 Percent of Sulfur Dioxide Measurements Within
Indicated Percent of Assigned Values (Statistical
Outliers Removed) 16
5 Audit Results for Nitrogen Dioxide 16
6 Audit Results for Nitrogen Dioxide by the Sodium
Arsenite Method 17
7 Percent of Nitrogen Dioxide Measurements Within
Indicated Percentage of Assigned Value (Statistical
Outliers Removed) . 18
8 Audit Results for Carbon Monoxide 18
9 Audit Results for Carbon Monoxide by the NDIR Method ... 19
10 Percent of Carbon Monoxide Measurements Within
Indicated Percentage of Assigned Value 19
11 Audit Results for Sulfate on Filter Strips 20
12 Audit Results for Sulfate by the Manual Methods 21
13 Audit Results for Sulfate by the Automated Methods .... 22
14 Percent of Sulfate Measurements Within Indicated
Percentage of Assigned Value 23
15 Audit Results for Nitrate on Filter Strips 24
16 Audit Results for Nitrate by the Automated Methods .... 25
17 Percent of Nitrate Measurements Within Indicated
Percentage of Assigned Value ............... 26
18 Audit Results for Lead on Filter Strips 27
19 Percent of Lead Measurements Within Indicated
Percentage of Assigned Value ..... 28
20 Audit Results for Sulfur Dioxide Continuous Monitors
(All Data) 29
21 Audit Results for Sulfur Dioxide Continuous Monitors
by Various Instrumental Methods ............. 29
22 Percent of Hi-Vol Flow Measurements Within
Indicated Percentage of Assigned Value (All Data) .... 30
23 Acid Rain Results for pH, Conductivity and Acidity
(All Data) 31
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TABLES (Con't.)
Number Page
24 Acid Rain Audit Results for pH, Conductivity and
Acidity (Outliers Removed) 32
25 Acid Rain Audit Results for Anions (All Data) 33
26 Acid Rain Audit Results for Anions (Outliers Removed). . . 34
27 Acid Rain Audit Results for Cations (All Data) 35
28 Acid Rain Audit Results for Cations (Outliers Removed) . . 36
29 Acid Rain Audit Results for Trace Metals (All Data). ... 37
30 Acid Rain Audit Results for Trace Metals
(Outliers Removed) . .......... 38
vi
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FIGURES
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
S02 Bubbler Audits . . ,
N02 Bubbler Audits . . ,
Carbon Monoxide Audits .
Sulfate Audits . . . . ,
Nitrate Audits . . . . ,
Lead Audits
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
A.cid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
Acid Rain Audit Results
for pH
for Conductivity ...
for Acidity ,
for 804 (Reported as S)
for NO3 (Reported as N)
for Cl
for F ,
for NH4 (Reported as N)
for Ca
for K ,
for Mg ,
for Na ,
for Mn ,
for Fe ,
for Cd ,
for Ca .,
for Ni ,
for Pb ,
for Zn .........
Page
39
39
40
40
41
41
42
42
43
43
44
44
45
45
46
46
47
47
48
48
49
49
50
50
51
vii
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ACKNOWLEDGMENTS
Recognition is due to the technical staff of Northrop Services, Inc.,
Research Triangle Park, North Carolina, who produced and analyzed all of
the high quality chemical samples utilized in the audits. Also, we thank
the staff of Global Geochemistry, Inc. for their responsive analytical
services as the referee laboratory. Appreciation is due, too, to our QAD/
EMSL colleagues, who contributed to the diverse activities associated with
the audits, in particular Linda Porter and Avis Mines.
viii
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SECTION 1
INTRODUCTION
The ambient air audits of analytical proficiency are managed by the
Environmental Monitoring Systems Laboratory (EMSL), of the U.S. Environmen-
tal Protection Agency (EPA). These audits are a part of a continuing
program entitled the National Performance Audit Program. This program
allows EPA to monitor the performance of laboratories (agencies) making air
pollution measurements to assist EPA in assessing the quality of air moni-
toring data. It also allows participating agencies to assess their per-
formance with respect to other agencies making similar measurements. The
audits are conducted by the Quality Assurance Division (QAD) of EMSL.
Inquiries and applications to participate should be directed to: U.S.
Environmental Protection Agency, Quality Assurance Division, Environmental
Monitoring Systems Laboratory, MD-77B, Research Triangle Park, North Caro-
lina 27711.
Agencies participating in the audits are mostly solicited by the EPA
Regional Quality Control Coordinator in each of EPA's 10 regions. Agencies
performing ambient air monitoring of criteria pollutants are required by
Federal regulation to participate. Once a laboratory enrolls in a particu-
lar audit, it is assigned a permanent identifying code number and automati-
cally notified of subsequent audits. Federal, state, local, industrial and
foreign air pollution monitoring agencies participate in the surveys.
Sample materials furnished for the audits simulate the several types
of collected air pollution samples as closely as possible. The materials
for the manual methods evaluate only the analytical portion of the total
air measurement process; i.e., they do not determine errors in sample
collection, transportation, handling, storage, and data processing. For
the high volume method for total suspended particulate (TSP), the audit
evaluates only the flow measurement portion of the method. Throughout this
report, reference is made to "assigned values." These values are the
standards against which reported results are evaluated and have been so
designated after consideration of the analytical results of the referee
laboratory, the QAD/EMSL Standards Laboratory, and the manufacturer of the
audit material.
In 1985, audits were conducted twice for lead, sulfate, nitrate and
acid rain and once for carbon monoxide, high-volume flow rate, and the man-
ual sulfur dioxide and nitrogen dioxide (bubbler) methods. Audits on
sulfur dioxide continuous monitors were conducted throughout the year.
Each laboratory participating in an audit received an evaluation of
its performance shortly after the audit was completed. When practical,
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laboratories submitting abnormally high or low results were offered an
opportunity to analyze another set of samples. However, the retest results
are not included in this summary report. In any case, laboratories having
excessively deviant values should have investigated their operations to
identify and correct the cause of the large errors.
Approximately 680 laboratories are registered in the National Ambient
Air Performance Audit Program. This report presents the results of approxi-
mately 425 laboratories that participated in the 1985 audits. The category
and number of participants in each audit are presented in Table 1. Compared
to the 1984 audits participation decreased in the following audits (per-
centage decline in parentheses): S02 bubbler (40%), N02 bubbler (15%), CO
(1.5%), high volume flow _rate (5%) and acid rain (6%). A 2% increase oc-
curred in the Pb and S0^~ on filter strip audits, but the NOg" on filter
strip audit was unchanged. A 16% increase occurred in the S02 continuous
monitor audit. These changes continue trends found in the earlier audits
(2, 3).
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SECTION 2
SUMMARY AND CONCLUSIONS
The 1985 results closely parallel those of the last two years (1, 2).
With outliers removed and the values for all levels averaged, the percentage
of results within 20 percent of the assigned values ranged from a low of 90%
(flow rate) to a high of 100% (N0£ and S02 bubbler methods). The following
percentage of results were rejected as outliers for each type of audit: S02
bubbler (5%), N02 bubbler (5.7%), CO (4.5%), SO,** (4.4%), NO," (8.3%), Pb
(5.27%), flow rate (3.8%), S02 continuous (1.0%) and acid rain (approxi-
mately 3%).
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SECTION 3
AUDIT MATERIALS
The audit samples span the wide range of pollutant concentrations
experienced in ambient air monitoring. This is achieved directly with the
CO samples, which are prepared in cylinders. Dilution is necessary for the
acid rain samples, lyophilized S02 and aqueous_N02 samples in order to obtain
desired concentrations. Lead, NOo , and S0^~ filter strip samples require
both dissolution and dilution to arrive at the needed range of concentra-
tions. The S02 continuous monitor audit samples require dilution of the
S02 with zero air.
Although many air monitoring sites rarely encounter pollutant concen-
trations at the higher audit sample levels, these concentrations are in-
cluded to assure that monitoring methods are verified at the higher levels.
The following paragraphs describe each sample type used in the 1985
audits.
SULFUR DIOXIDE (MANUAL)
Lyophilized samples, composed of sodium sulfite and potassium tetra-
chloromercurate, simulate ambient air samples collected according to the
Pararosaniline Method, the reference method for determining S02 in the
atmosphere. In the 1985 audits, the concentrations ranged from approxi-
mately 45 to 270 iag of sulfur dioxide equivalent per cubic meter when
reconstituted properly. A sample set consisted of five different concen-
trations. (This audit is being discontinued due to the small number of
participants.)
NITROGEN DIOXIDE (MANUAL)
Nitrogen dioxide samples consist of aqueous sodium nitrite solutions
that simulate ambient M>2 samples collected by a 24-hour N02 bubbler method.
Audit results are expressed in terms of micrograms per milliliter (nitrite
concentration). These solutions, when properly diluted according to direc-
tions, are equivalent to collected atmospheric N02 concentrations of approx-
imately 0.3 to 1.1 vig/mL. A sample set consists of five different concen-
trations.
CARBON MONOXIDE
These audit materials consist of a mixture of CO, C02 and City and zero
air in a disposable pressurized gas cylinder that simulates an ambient air
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sample. The concentrations of the three CO samples used in the 1985 audits
ranged from 7 to 40 ppm. Directions specify that the gas sample be Intro-
duced into a continuous analyzer in the "sample" mode, which permits the
analyzer to draw the sample in the same fashion and at the same flow rate
as during ambient air monitoring.
SULFATE, NITRATE, AND LEAD ON FILTER STRIPS
The filter strip samples used in sulfate, nitrate and lead audits are
each 1.9 cm wide by 20 cm long. They are cut from 20- by 24-centimeter
glass fiber filters that have been spiked with an aqueous solution of the
appropriate solution and then oven dried. After analysis, pollutant con-
centrations are computed by assuming that the samples were collected on the
prescribed high-volume filter with a sample air volume of 2,000 m3. Six
sample strips comprise a set.
Sulfate and nitrate audit samples are prepared from sodium sulfate and
potassium nitrate. Calculated nitrate concentrations ranged from 0.66 to
14.0 pg/m3 and sulfate from 1.6 to 26.0 pg/m3. Lead samples, which are
prepared from lead nitrate ranged in concentration from 0.45 to 6.7 pg/m3
of lead.
HIGH-VOLUME FLOW RATE (ReF DEVICE)
The reference flow (ReF) device used for audits of high-volume flow
rates consist of a modified orifice, a wind deflector, a manometer, and a
series of resistance plates that simulate particulate loading. A single
ReF device Is supplied to each participating agency with instructions to
check samplers at as many sampling sites as feasible within the allotted
time.
Before use in the audit each ReF device is calibrated with a positive
displacement meter traceable to NBS. During the audit, the device is
mounted on top of the sampler, replacing the filter face plate. A wind
deflector is used to prevent fluctuations In the measurements due to wind
blowing across the orifice.
SULFUR DIOXIDE CONTINUOUS MONITORS
The continuous monitor auditing system is an auditing device for S02
continuous ambient air monitors. The device Is a porous plug dilution
system that provides a mechanism whereby controlled quantities of S02 and
diluent air are continuously combined in a mixing chamber and passed into
the monitor. The flow rate of each gas is controlled by maintaining a
predetermined pressure drop across the porous plus flow restrictor. Vari-
able S02 concentrations are obtained by switching between four restrictors.
The audit device, which is housed in a compact, lightweight, impact-
resistant case, is constructed so that only those controls required for
system operation are exposed. By opening and closing different toggle
valves, it is possible to generate up to seven preset pollutant concentra-
tions. Five are used for the audit. Two compressed gas cylinders are
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supplied with each unit, one as the pollutant source and the other for
dilution.
Each audit device is calibrated for flow at all the settings used in
the audit. Flow calibrations are referenced to laminar flow elements
traceable to National Bureau of Standards flow standards. Sulfur dioxide
concentrations ranging from 0.0 to 0.9 ppm were used in the 1985 audits.
ACID RAIN
Five aqueous solutions in polyethylene bottles containing the anions
and cations found in rain water were shipped to each of the participating
laboratories. All samples were diluted 1:50 by the participant. Three sam-
ples were then analyzed for pH, conductivity, acidity and the major cations
and anions normally measured in precipitation samples and the other two for
heavy metals. The latter two samples were acid stabilized in the concentrate
form to prevent loss of metals from the solution.
The chemical composition of these samples was certified by the U.S.
National Bureau of Standards. The participants analyzed the samples using
the analytical procedures they normally employ when analyzing their precip-
itation samples. The results were reported based on the sample concentra-
tion after the 1:50 dilution.
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SECTION 4
AUDIT RESULTS
The results of the 1984 audit are presented in Tables 2 through 31.
The term "audit mean" in these tables denotes the average of all values re-
ported by the participants for that sample after elimination of outliers.
Elimination of outliers was accomplished in a two step procedure. First,
results from laboratories/sites whose values for all samples exceeded ± 20
percent of the assigned value were removed from the data base. These ex-
cluded values represented 5.7 percent of the total number of laboratories/
sites reporting results which is approximately the same as for 1982 through
1984 (1, 2, 3). Then, individual sample results were rejected as outliers
based on Chauvenet's Criterion (4). After eliminating outliers, the results
from all participants were found to be normally distributed which was ex-
pected based on experience (1, 2, 3).
At each audit level, the percent accuracy (% Ace.) and the precision,
as measured by the percent coefficient of variation (%CV), were calculated
using Equations 1 and 2, respectively. The percent accuracy measures how
well the average of all participants agrees with EPA's assigned values.
The percent coefficient of variation measures the variability among parti-
cipants.
% Ace. = audit mean - EPA assigned value x IQQ (1)
EPA assigned value
% CV = audit standard deviation x IQQ (2)
audit mean
Overall accuracy and precision values for each audit were also calcu-
lated and plotted (Figures 1 through 25) to show the historical record of
performance for each type of audit. All of the figures present the results
of the performance audits after elimination of the outliers. Many readers
may find that scanning these figures provides a better understanding of the
1985 results compared to scanning the tabulated results and reading the
text of this report.
SULFUR DIOXIDE (BUBBLER)
Twelve laboratories participated in the audit 40 percent less than in
1984 (1). Participation has steadily decreased since 1981 due to the in-
creasing number of laboratories changing to automated analyzers. Because of
the low level of participation, this audit is being discontinued.
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The audit mean, percent accuracy and percent CV, with and without out-
liers, are reported in Table 2. As usual the lowest precision and accuracy
was achieved in level one. Overall, however, the average percent accuracy
appears to have stabilized over the past five audits when compared to
audits of previous years (Figure 1). Precision has continued to improve
(Figure 1).
As shown in Table 3, accuracy for the manual pararosaniline method,
ranged from -2.14 to 7.16% for all data after outliers are removed. Accu-
racy for the automated method ranged from -0.43 to 6.04% for all data after
outliers were removed. As before (1, 2, 3) sample concentration did not
appear to affect the precision for either method.
Table 4, constructed with the outliers removed, shows the percentage of
laboratories that obtained results within ± 10, 20, 30 and 50 percent of the
assigned values. Better than 92 percent of the measurements fell within 20
percent of the assigned values, a greater percentage than 1984 (90%), 1983
(87%), and 1982 (88%).
NITROGEN DIOXIDE
Eighteen laboratories participated in the 1985 audit 15% less than
in 1984 (1). The decrease, which occurred among the state and local parti-
cipants, likely resulted because an increasing number of laboratories are
replacing bubblers with continuous analyzers. Because of the low level of
participation, this audit is being discontinued.
The audit mean, percent accuracy and percent CV with and without out-
liers are reported in Tables 5 and 6. Figure 2 shows that with a few
exceptions the precision and accuracy over the years has been good.
CARBON MONOXIDE
In 1985, 323 monitors were audited a 1.5% decrease from 1984.
Eighty-six percent of the monitors audited were NDIR compared to 95% in
1984 (1) and 1983 (2). This decrease was offset by a large increase in gas
filter correlation CO monitors. However, the small number of these latter
monitors used in the 1984 audit prevents a meaningful comparison from being
made between 1984 and 1985.
As shown in Figure 3, both precision and accuracy have stayed at the
same level for the last six years. Also, the number of measurements falling
within 20% of the assigned value (Table 10) closely parallels the 1982
through 1984 results (1, 2, 3). Also, as shown in Figure 3, the accuracy
has oscillated back and forth across the zero-axis for the last five years.
SULFATE ON FILTER STRIPS
Approximately 55 laboratories participated in each audit. The audit
mean, percent accuracy and precision are given in Table 11. Over the years
accuracy has varied quite a bit, but now it seems to have stabilized (Figure
4). Precision has also stabilized after improving continually for several
years.
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As in 1984, there also is no apparent relationship between concentration
and either precision or accuracy for the manual and for the automated
methods (Table 13).
Except for the lowest sample concentration, between 72 and 100 percent
of the laboratories reported results within t 20 percent of the assigned
values (Table 14) about the same as in 1984 (1).
NITRATE ON FILTER STRIPS
Approximately 45 laboratories participated in each 1985 audit. Parti-
cipation was down approximately 2 percent from 1984. As in the sulfate
audits, the number of participants has been fairly constant since 1979.
Both accuracy and precision seem to have reached a plateau with no improve-
ment evident for the last couple of years (Figure 5).
The results from the 1985 nitrate audits show a slight increase in both
precision and accuracy with respect to the 1984 audits (Figure 5, Table
15). This increase occurred in the automated methods (Table 16), more so
than in the manual analytical methods.
Some other methods used by a few of the participants included the man-
ual cadmium reduction, brucine, hydrazine, 2,4 xylenol, selective ion elec-
trode, and the szechrome NAS methods. The number of results reported was
too small to calculate precision and accuracy.
The percentage of values that fell within ± 20 percent of the assigned
values (Table 17) was higher (90%) than in 1984 (84%) and identical to that
for 1983 and 1982 (90%).
LEAD ON FILTER STRIPS
One hundred and seven laboratories participated in the 0185 audit and
102 in the 0785, a 2 percent increase over the 1984 audits. The increase
was due to an increase in participation from local agencies. Participation
has leveled off in the past three years, ranging from 95 to 107 laborator-
ies per audit.
The audit mean, percent accuracy and percent CV (precision) are shown
in Table 18. Accuracy has continued to show the negative bias present
since the audits were initiated in 1977, but the bias was considerably less
than for the period 1982-1984 (Figure 6). Precision has remained at the
same level since 1982 (Figure 6) and in 1985, the number of measurements
within t 20 percent of the assigned value (97%) was the same as in 1984 (1)
and 1983 (2) (Table 19). This year all participants used atomic absorption
for sample analysis.
SULFUR DIOXIDE (CONTINUOUS MONITORS)
The number of monitors audited totaled 257 (Table 20). Compared to
1984, this increase of 16 percent resulted mainly from an equal increase in
participation by both state and local agencies.
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The accuracy for each of the methods is shown in Table 21. The methods
most commonly used were: fluorescence (243), flame photometric (7) and
coulometric (4). In relation to 1984, these numbers represent a 19% in-
crease, 16% decrease and 20% decrease, respectively. The decrease in the
number of flame photometric and coulometric analyzers and the large increase
in the number of fluorescent analyzers continues the shift in user preference
for the fluorescence monitor observed earlier (1, 2). The accuracy of the
fluorescent improved compared to 1984 (1), but the accuracy of the other
two types decreased slightly.
HIGH VOLUME
The number of monitors audited in 1985 was 1336 a 4% decrease from
1984 (1). The pressure transducer continued to be the most widely used
method of measurement (50.3%), the rotaraeter was next (20.8%), followed by
the flow controller (4.1%). Other methods which accounted for the remaining
24.8 percent of the results, included: orifice manometer, manometer, flow
gauge, and pressure transducer/non-continuous. Table 22 shows the percent-
age of the flow measurements within ± 10, 20, 30 and 50% of the true value
for each resistance plate used in the ReF (audit) device. These results
are similar to the 1984 (1) and 1983 (2) results.
ACID RAIN
Thirty-three laboratories participated in the 0485 audit and thirty-
three participated in the 1185 audit. Overall this represents a 6% de-
crease in participation compared to 1984. Because of the short history of
this audit, it is possible at this time to make only general observations
concerning time trends. Also, because of the low concentrations present in
some of the samplers, the relative precision sometimes appears as poor,
when, in absolute terms (e.g., mg/1) the precision is reasonably good.
Results for pH, Conductivity and Acidity
The results are presented in Table 24 (all data), Table 25 (outliers
removed) and in Figures 7 (pH), 8 (conductivity) and 9 (acidity). As in the
earlier audits (1, 2, 3), there is, at best, only a weak correlation apparent
between sample concentration and precision and accuracy. This is very dif-
ferent from the ambient air audits reported earlier where precision and
accuracy generally correlate with concentration. For both pH and acidity,
precision and accuracy have remained essentially the same (Figures 7 and 8,
respectively). On the other hand, the accuracy of the acidity measurement
has varied widely (Figure 9) and precision continues to improve but in an
erratic manner.
10
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Major Anions Results (804, N03, Cl, F)
The results for these four parameters are presented in Table 26 (all
data), Table 27 (outliers removed) and in Figures 10 (804), 11 (N03), 12
(Gl) and 13 (F). As in the past, precision continued to exceed 10 percent in
all audits and also remained erratic. As shown by comparing the precision
in Tables 26 and 27, however, removal of only a few results yields a large
improvement in precision. Thus, the results are not as poor as they appear.
Major Cations (NH4, Ca, K, Mg, Na)
The results for these five major ions are presented in Table 28 (all
data), Table 29 (outliers removed) and in Figures 14 (NIty), 15 (Ca), 16 (K),
17 (Mg) and 18 (Na). As in the case for the major anions, the precision
has been erratic for all five anions over the history of the audit. But,
as in the case for the major anions, removing just one or two values yields
a dramatic improvement in precision.
Trace Metals Results (Mn, Fe, Cd, Cu, Ni, Pb, Zn)
The results for these seven metals are presented in Table 30 (all
data), Table 31 (outliers removed) and in Figures 19 (Mn), 20 (Fe), 21 (Cd),
22 (Cu), 23 (Ni), 24 (Pb), and 25 (Zn). Also as in the case of both the
anions and cations, the precision has varied in an erratic manner for most
of these metals (Zn continues to be the exception). It should be borne in
mind, however, that the small concentrations used for these metals does
mean that a small absolute difference appears as a large relative difference.
11
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REFERENCES
1. Parr, B.F., R.L. Lampe, G. Pratt, O.L. Dowler and W.J. Mitchell. Na-
tional Performance Audit Program. Ambient Air Audits of Analytical
Proficiency, 1984. U.S. Environmental Protection Agency Report EPA
600/4-86-013. Research Triangle Park, North Carolina 27711. Febru-
ary 1986.
2. Lampe, R.L., B.F. Parr, G. Pratt, O.L. Dowler and W.J. Mitchell. Na-
tional Performance Audit Program. Ambient Air Audits of Analytical
Proficiency, 1983. U.S. Environmental Protection Agency Report EPA
600/4-84-077. Research Triangle Park, North Carolina 27711. October
1984.
3. Lampe, R.L., B.F. Parr, B.I. Bennett, G. Pratt and W.J. Mitchell. Na-
tional Performance Audit Program. Ambient Air Audits of Analytical
Proficiency, 1982. U.S. Environmental Protection Agency Report EPA
600/4-84-005. Research Triangle Park, North Carolina 27711. January
1984.
4. Chauvenet, W. A Manual of Spherical and Practical Astronomy. J.B.
Lipincott and Company, Philadelphia, Pennsylvania, 1863. pp. 558-566.
12
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TABLE 1. AGENCY PARTICIPATION
Distribution (%)
Survey
S02 June 1985
N02 June 1985
CO May 1985
804 February 1985
804 August 1985
N03 February 1985
N03 August 1985
Pb January 1985
Pb July 1985
S02 (continuous)
High- Volume Flow-Rate
May 1985
Acid Rain April 1985
Acid Rain October 1985
States
42.0
33.3
52.0
51.8
45.8
52.2
52.4
40.2
42.2
58.4
38.5
42.4
39.4
Local
33.0
44.4
41.8
13.8
16.7
12.5
11.9
26.2
28.4
40.5
44.8
12.1
12.1
Industry
25
22
2
24
20
25
19
27
24
0
14
30
33
.0
.3
.5
.1
.8
.0
.0
.1
.5
.0
.2
.3
.3
Federal
0.
0.
1.
1.
4.
2.
2.
1.
2.
00
0.
15.
15.
0
0
5
7
2
0
4
9
0
.1
5
1
1
Foreign
0
0
2
8
12
8
14
4
2
0
2
0
0
.0
.0
.1
.6
.5
.3
.3
.9
.9
.0
.0
.0
.0
No. of
Laboratories3
12
18
58
51
48
42
107
102
33
33
(0)
(0)
(0)
(2)
(2)
(2)
(5)
(2)
No. of
Monitors3
325 (11)
__
257 (2)
1336 (113)
aValue in parentheses is the number of laboratories/monitors that reported all values off by more than ±
from the true value.
-------
TABLE 2. AUDIT RESULTS FOR MANUAL SULFUR DIOXIDE
METHOD (BUBBLER)
Audit
Level
n
Assigned
value (pg/m3)
Mean
(pg/m3)
Ace.
% CV
0685
0685
1
2
3
4
5
1
2
3
4
5
12
12
12
12
12
12
11
11
12
11
A. ALL DATA
44.30 43.60 -1.58 14.06
61.00 62.55 2.54 9.40
90.60 96.75 6.79 7.43
124.50 128.97 3.59 6.09
271.90 279.05 2.63 7.15
B. OUTLIERS REMOVED
44.30
61.00
90.60
124.50
271.90
43.60
61.06
95.30
128.97
274.69
-1.58
0.10
5.19
3.59
1.03
14.06
4.83
5.66
6.09
4.98
14
-------
TABLE 3. RESULTS FOR'THE PARAROSANILINE METHOD
Manual Method (01)
Audit Level
Assigned
value
(pg/m3)
n
Mean
(yg/m3)
% Ace.
% CV
n
Automated
Mean
(Ug/m3)
Method (02)
% Ace.
% CV
A. ALL DATA
0685 1
2
3
4
5
0685 1
2
3
4
5
44.
61.
90.
124.
271.
44.
61.
90.
124.
271.
30
00
60
50
90
30
00
60
50
90
8
8
8
8
8
8
7
8
8
8
43
63
97
130
282
43
60
97
130
282
.35
.18
.09
.61
.89
B.
.35
.93
.09
.61
.89
-2.14
3.57
7.16
4.91
4.04
OUTLIERS
-2.14
-0.11
7.16
4.91
4.04
17.23
11.44
8.49
6.51
7.63
REMOVED
17.23
6.07
8.49
6.51
7.63
4
4
4
4
4
4
4
4
4
4
44.11
61.29
96.07
125.68
271.38
44.11
61.29
96.07
125.68
271.38
-0.43
0.48
6.04
0.91
-0.19
-0.43
0.48
6.04
0.91
-0.19
5.96
2.03
5.71
4.74
5.89
5.96
2.03
5.71
4.74
5.89
-------
TABLE 4. PERCENT OF SULFUR DIOXIDE MEASUREMENTS WITHIN
INDICATED PERCENT OF ASSIGNED VALUES
Audit
0685
Level
1
2
3
4
5
Assigned
value (ug/nr*)
43.60
61.00
90.60
124.50
271.90
10%
50.0
91.7
75.0
83.3
91.7
20%
83.3
91.7
91.7
100.0
91.7
30%
100.0
100.0
100.0
100.0
100.0
50%
100.0
100.0
100.0
100.0
100.0
TABLE 5. AUDIT RESULTS FOR NITROGEN DIOXIDE
MANUAL METHOD (BUBBLER)
Audit
0685
Level
1
2
3
4
5
n
18
18
18
17
16
Assigned
value (yg/ml)
A. ALL DATA
0.345
0.434
0.686
0.944
1.114
Mean
(yg/ml)
0.353
0.442
0.698
0.908
1.119
% Ace.
2.32
1.14
1.31
3.81
0.45
% CV
8.78
3.62
3.02
13.88
4.83
B. OUTLIERS REMOVED
0685
1
2
3
4
5
17
16
18
16
15
0.345
0.437
0.686
0.944
1.114
0.346
0.442
0.695
0.938
1.131
0.29
1.14
1.31
-0.64
1.53
3.18
2.49
3.02
2.13
2.39
16
-------
TABLE 6. AUDIT RESULTS FOR NITROGEN DIOXIDE BY THE SODIUM ARSENITE METHOD
Manual Method (05)
Audit Level
0685 1
2
3
4
5
0685 1
2
3
4
5
Assigned
value
(yg/mL)
0.345
0.437
0.686
0.944
1.114
0.345
0.437
0.686
0.944
1.114
n
13
13
13
12
11
12
12
13
11
10
Mean
(pg/mL) % Ace.
0.355
0.440
0.691
0.893
1.104
B.
0.346
0.436
0.691
0.935
1.120
A. ALL DATA
2.90
0.69
0.73
-5.40
-0.90
% CV
10.14
4.32
3.04
16.69
5.25
n
4
4
4
4
4
Automated Method (06)
Mean
(yg/mL)
0.348
0.449
0.705
0.940
1.152
% Ace.
0.87
2.75
7.77
0.21
3.41
% CV
1.44
1.33
3.26
2.11
1.74
OUTLIERS REMOVED
0.29
0.23
0.73
-0.95
0.54
3.47
3.44
3.04
2.25
2.14
4
4
4
4
4
0.348
0.479
0.705
0.940
1.152
0.87
2.75
2.77
0.21
3.41
1.44
1.33
3.26
2.11
1.74
-------
TABLE 7. PERCENT OF NITROGEN DIOXIDE MEASUREMENTS WITHIN
INDICATED PERCENTAGE OF ASSIGNED VALUE
Audit
0685
Level
1
2
3
4
5
Assigned
value (pg/mL)
0.345
0.437
0.686
0.944
1.114
10%
94.4
100.0
100.0
88.9
83.3
20%
94.4
100.0
100.0
88.9
88.9
30%
94.4
100.0
100.0
88.9
88.9
50%
100.0
100.0
100.0
88.9
88.9
TABLE 8. AUDIT RESULTS FOR CARBON MONOXIDE
Audit
0585
Level
1
2
3
n
323
326
317
Assigned
value (ppm)
A. ALL DATA
6.70
16.50
39.90
Mean
(ppm)
6.91
16.60
40.08
% Ace.
3.13
0.61
0.45
% CV
42.55
11.08
11.38
B. OUTLIERS REMOVED
0585
1
2
3
309
310
304
6.70
16.50
39.90
6.65
16.51
40.09
-0.75
0.06
0.48
7.67
3.27
3.19
18
-------
TABLE 9. AUDIT RESULTS FOR CARBON MONOXIDE BY THE NDIR METHOD
Assigned NDIR
Audit Level value (ppm) n Mean (ppm) % Ace. % CV
A. ALL DATA
0585 1 6.70 278 6.75 0.75 46.82
2 16.50 281 16.58 0.48 8.02
3 39.90 273 39.96 0.15 10.04
B. OUTLIERS REMOVED
0585
1
2
3
6.70
16.50
39.90
269
269
265
6.66
16.56
40.11
-0.59
0.36
0.53
7.96
3.20
3.29
TABLE 10. PERCENT OF CARBON MONOXIDE MEASUREMENTS WITHIN INDICATED
PERCENTAGE OF ASSIGNED VALUE
Assigned
Audit Level value (ppm) 10% 20% 30% 50%
A. ALL DATA
0585 1 6.70 85.0 96.9 97.2 98.1
2 16.50 95.1 99.1 99.7 99.7
3 39.90 92.3 96.3 96.3 96.3
B. OUTLIERS REMOVED
0585 1 6.70 88.5 97.8 98.1 98.4
2 16.50 98.1 100.0 100.0 100.0
3 39.90 95.2 97.1 97.1 97.1
19
-------
TABLE 11. AUDIT RESULTS FOR SULFATE ON FILTER STRIPS
Audit
Level
n
Assigned
value (yg/m3)
Mean
(yg/m3)
% Ace.
% CV
A. ALL DATA
0285
0885
0285
0885
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
54
56
58
58
58
58
50
50
51
51
51
51
54
55
57
55
57
57
47
45
47
47
48
48
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
B. OUTLIERS
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
1.69
2.98
10.46
8.71
18.93
23.48
2.79
3.80
11.57
25.34
18.08
5.22
REMOVED
1.69
2.95
10.50
8.63
18.77
23.58
2.45
3.59
11.83
26.50
18.50
5.24
9.03
-2.61
-3.06
0.35
-1.66
-2.53
33.49
5.56
-2.03
-2.73
-3.06
2.76
9.03
-3.59
-2.69
-0.58
-2.49
-2.12
17.22
-0.28
0.17
1.73
-0.70
3.15
34.32
16.44
7.65
12.17
10.94
6.43
81.72
26.05
15.56
12.63
17.70
19.73
34.32
14.92
7.14
8.46
8.90
5.60
42.86
7.74
6.85
5.25
6.48
13.36
20
-------
TABLE 12. AUDIT RESULTS FOR SULFATE BY THE MANUAL METHODS
BaCl2 (17)
Audit
0285
0885
Level
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value
(yg/m3)
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
n
9
9
9
9
9
9
6
6
6
6
6
6
Mean
(yg/rn3)
2.21
3.48
10.20
9.13
18.80
23.48
3.20
4.33
10.84
22.59
16.61
5.20
% Ace.
A. ALL DATA
45.58
13.73
-5.46
5.18
-2.34
-2.53
53.11
20.28
-8.21
-13.38
-10.94
2.36
% CV
35.75
20.98
12.25
23.22
13.88
7.62
46.88
35.56
31.83
32.23
30.10
27.12
n
1
2
3
3
3
3
2
2
2
2
2
2
Sulfa-Ver (19)
Mean
(yg/m3)
1.34
2.69
11.13
9.03
19.40
23.40
3.45
4.20
11.85
24.20
18.70
4.75
% Ace.
-13.58
-12.89
3.18
4.03
0.78
-2.86
65.07
16.67
0.34
-7.10
0.27
-6.50
% CV
0.00
4.46
9.61
4.65
8.81
12.05
116.81
80.71
1.77
12.27
5.29
72.84
B. OUTLIERS REMOVED
0285
0885
1
2
3
4
5
6
1
2
3
4
5
6
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
9
9
9
9
9
9
5
5
5
5
5
5
2.21
3.48
10.20
9.13
18.80
23.48
3.33
4.68
12.20
25.51
18.61
5.66
42.58
13.73
-5.46
5.18
-2.34
-2.53
59.33
30.00
3.30
2.07
-0.21
11.42
35.75
20.98
12.25
23.22
13.88
7.62
30.56
30.56
8.85
5.80
5.96
16.43
1
2
3
3
3
3
2
2
2
2
2
2
1.34
2.69
11.13
9.03
19.40
23.40
3.45
4.20
11.85
24.20
18.70
4.75
-13.55
-12.09
3.15
4.03
0.78
-2.80
65.07
16.67
0.34
-7.10
0.27
6.50
0.00
4.46
9.61
4.65
8.81
12.05
116.81
80.71
1.72
12.27
5.29
72.84
-------
TABLE 13. AUDIT RESULTS FOR SULFATE BY THE AUTOMATED METHODS
N5
ISJ
Methyl Thymol Blue (16)
Audit
0285
0885
0285
0885
Level
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value
(pg/m3)
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
n
26
27
28
28
28
28
22
22
23
23
23
23
25
26
26
26
27
26
20
20
22
22
21
21
Mean
(pg/m3)
1.64
2.87
10.45
8.69
19.23
23.26
2.09
3.82
12.04
26.15
18.26
5.36
B.
1.58
2.91
10.60
8.50
18.90
23.74
2.18
3.61
11.84
25.79
18.72
5.12
% Ace.
A. ALL DATA
5.81
-9.22
-3.15
0.12
-0.10
-0.01
41.63
5.56
2.29
0.38
-2.09
5.51
% CV
32.93
14.63
6.79
9.32
11.80
4.71
106.08
20.42
10.38
8.72
21.14
18.10
n
16
16
16
16
16
16
16
16
16
16
16
16
Ion Chromatograph (34)
Mean
(pg/m3)
1.53
2.91
10.44
8.38
18.45
22.95
2.08
3.45
10.99
25.27
17.29
4.99
% Ace.
-1.29
-4.90
-3.24
-3.46
-4.16
-4.73
-0.48
-4.17
-7.46
-2.99
-3.91
-1.77
% CV
24.18
10.65
5.75
7.04
8.46
7.71
16.83
7.83
15.92
7.72
7.92
12.02
OUTLIERS REMOVED
1.94
-4.90
-1.76
-2.07
-1.82
-1.45
4.31
0.28
0.25
-1.00
0.38
0.79
30.38
12.37
4.06
4.47
7.78
3.37
13.70
8.03
6.67
5.97
4.81
7.81
15
14
15
15
15
15
14
15
15
14
15
15
1.45
2.90
10.53
8.49
18.70
23.29
1.96
3.49
11.36
25.18
18.15
4.87
-6.45
-5.23
-2.41
-2.19
-2.86
-3.32
-6.22
-3.06
-3.81
-3.34
-3.22
-4.13
13.10
5.52
4.75
5.60
6.58
5.11
7.14
6.30
8.54
2.79
6.17
7.80
-------
TABLE 14. PERCENT OF SULFATE MEASUREMENTS WITHIN
INDICATED PERCENTAGE OF ASSIGNED VALUE
Audit
Level
Assigned
value (pg/m^)
10%
20%
30%
50%
A. ALL DATA
0285
0885
0285
0885
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1.55
3.06
10.79
8.68
19.25
24.09
2.09
3.60
11.81
26.05
18.65
5.08
B. OUTLIERS
Same As For All
2.09
3.60
11.81
26.05
18.05
5.08
39.7
53.4
82.8
81.0
72.4
86.2
45.1
54.9
78.4
84.3
86.3
66.7
REMOVED
Data
46.9
57.1
81.6
87.8
89.8
69.4
65.5
77.6
94.8
89.7
93.1
98.3
62.7
72.5
90.2
96.1
92.2
80.4
65.3
75.5
93.9
100.0
95.9
83.7
70.7
91.4
100.0
93.1
98.3
100.0
68.6
84.3
92.2
96.1
92.2
88.2
69.4
85.7
95.9
100.0
98.0
91.8
77.5
89.7
100.0
100.0
100.0
100.0
76.5
86.3
96.1
98.0
96.1
96.1
77.6
87.8
98.0
100.0
98.0
98.0
23
-------
TABLE 15. AUDIT RESULTS FOR NITRATE ON FILTER STRIPS
Audit
0285
0885
Level
1
2
3
4
5
6
1
2
3
4
5
6
n
47
47
48
48
48
48
41
41
42
42
42
42
Assigned
value (yg/m3)
A. ALL DATA
0.66
1.92
4.76
8.32
10.69
13.18
0.74
2.15
5.34
9.72
11.44
13.43
Mean
(yg/m3)
0.68
1.94
4.71
8.09
10.53
12.71
0.99
2.05
5.19
9.33
10.68
12.84
% Ace.
3.03
1.04
-1.05
-2.76
-1.50
-3.57
25.25
-4.65
-2.81
-4.18
-6.64
-4.39
% CV
25.00
24.74
20.81
17.68
17.85
17.62
131.31
24.88
20.81
20.90
25.47
20.02
B. OUTLIERS REMOVED
0285 1 43 0.66 0.70 6.06 15.71
2 43 1.92 1.93 0.52 8.29
3 44 4.76 4.86 2.09 5.14
4 45 8.32 8.33 0.12 5.64
5 45 10.69 10.82 1.22 7.12
6 44 13.18 13.00 -1.37 5.62
0885 1 38 0.74 0.81 9.46 37.04
2 37 2.15 2.13 -0.93 10.80
3 37 5.34 5.43 1.69 6.26
4 38 9.72 9.71 -0.10 7.00
5 39 11.44 11.37 -0.61 8.62
6 38 12.43 13.39 -0.30 4.93
24
-------
TABLE 16. AUDIT RESULTS FOR NITRATE BY THE AUTOMATED METHODS
Ul
Ion Chromatograph (34)
Audit
0285
0885
0285
0885
Level
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value
(pg/m3)
0.66
1.92
4.76
8.32
10.69
13.18
0.74
2.15
5.34
9.72
11.44
13.43
0.66
1.92
4.76
8.32
10.69
13.18
0.74
2.15
5.34
9.72
11.44
13.43
n
14
14
14
14
14
14
16
16
16
16
16
16
13
13
13
13
13
13
15
15
14
15
15
15
Mean
(pg/m3)
0.74
1.88
4.77
8.33
10.69
13.17
0.88
2.18
5.26
9.47
11.14
13.32
B.
0.70
1.90
4.82
8.21
10.52
12.96
0.80
2.14
5.44
9.60
11.27
13.54
% Ace.
A. ALL DATA
12.12
-2.08
0.21
0.12
0.00
-0.08
18.92
1.40
-1.50
-2.57
-2.62
-0.82
% CV
20.27
5.85
6.29
7.32
8.33
7.06
40.91
10.10
10.65
7.29
7.27
8.03
n
19
19
20
20
20
20
15
15
16
16
16
16
Cadmium Reduction (12)
Mean
(pg/m3)
0.67
2.15
4.88
8.33
11.02
13.33
0.69
1.91
5.16
9.31
10.75
12.72
% Ace.
1.52
11.98
2.52
0.12
3.09
1.14
-6.76
-11.16
-3.37
-4.22
-6.03
-5.29
% CV
20.90
24.65
19.06
6.12
6.53
6.08
34.78
25.65
20.54
21.05
19.91
20.13
OUTLIERS REMOVED
6.06
-1.04
1.26
-1.32
-1.59
-1.67
8.11
-0.47
1.87
1.23
-1.49
0.82
10.00
4.74
4.98
5.48
6.18
4.09
26.25
7.01
4.78
4.69
5.50
4.80
18
17
18
20
19
19
13
13
14
13
15
15
0.69
1.98
4.86
8.33
10.89
13.19
0.76
2.09
5.33
9.76
11.28
13.35
4.55
3.13
2.10
0.12
1.87
0.08
2.70
-2.79
-0.19
0.41
-1.40
-0.60
19.49
5.56
5.35
6.12
6.98
4.17
17.11
6.22
5.44
4.61
3.90
3.90
-------
TABLE 17. PERCENT OF NITRATE MEASUREMENTS WITHIN
INDICATED PERCENTAGE OF ASSIGNED VALUE
Audit
0285
0885
0285
0885
Level
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value (ug/nr')
A. ALL
0.66
1.92
4.76
8.32
10.69
13.18
0.74
2.15
5.34
4.72
11.44
13.43
B. OUTLIERS
0.66
1.92
4.76
8.32
10.69
13.18
0.74
2.15
5.34
4.72
11.44
13.43
10%
DATA
43.7
72.9
81.3
85.4
79.2
85.4
47.6
66.7
78.6
73.8
81.0
85.7
REMOVED
45.7
76.1
84.8
88.4
82.6
89.1
50.0
70.0
82.5
77.5
85.0
90.0
20%
66.7
87.5
91.7
95.8
89.6
91.7
59.5
81.0
88.1
90.5
88.1
92.9
69.6
91.3
95.7
100.0
93.5
95.7
62.5
85.0
92.5
95.0
92.5
97.5
30%
81.3
87.5
91.7
95.8
95.8
95.8
66.7
85.7
95.2
95.2
90.5
95.2
84.8
91.3
95.7
100.0
100.0
100.0
70.0
90.0
100.0
100.0
95.0
100.0
50%
89.6
89.6
91.7
95.8
95.8
95.8
85.7
90.5
95.2
95.2
92.9
95.2
93.5
93.5
95.7
100.0
100.0
100.0
85.0
95.0
100.0
100.0
97.5
100.0
26
-------
TABLE 18. AUDIT RESULTS FOR LEAD ON FILTER STRIPS
Audit
0185
0785
0185
0785
Level
1
2
3
4
5
6
2
3
4
5
6
7
1
2
3
4
5
6
2
3
4
5
6
7
n
107
107
107
107
106
107
102
102
102
102
101
100
100
100
102
101
99
100
98
99
98
96
97
95
Assigned
value (jag/m3)
A. ALL DATA
0.53
1.06
3.03
4.31
4.83
6.65
0.45
1.00
1.15
2.00
2.70
5.40
B. OUTLIERS REMOVED
0.53
1.06
3.03
4.31
4.83
6.65
0.45
1.00
1.15
2.00
2.70
5.40
Mean
(pg/m3)
0.52
1.05
2.96
4.10
4.73
6.40
0.50
1.00
1.12
1.99
2.76
5.23
0.52
1.06
2.95
4.13
4.77
6.44
0.46
1.01
1.13
2.01
2.74
5.34
% Ace.
-1.89
-0.94
-2.31
-4.87
-2.07
-3.76
11.11
0.00
-2.61
-0.50
2.22
-3.15
-1.89
0.00
-2.64
-4.18
-1.24
-3.16
2.22
1.00
-1.74
0.50
1.48
-1.11
% CV
9.62
8.57
6.42
6.34
7.19
5.78
70.00
8.00
8.04
8.04
12.68
11.47
7.69
5.66
3.73
3.87
3.77
3.42
10.87
6.93
7.08
5.97
6.20
6.55
27
-------
TABLE 19. PERCENT OF LEAD MEASUREMENTS WITHIN
INDICATED PERCENTAGE OF ASSIGNED VALUE
Audit
Level
Assigned
value ( ug/
m3) 10%
20%
30%
50%
A. ALL DATA
0185
0785
0185
0785
1
2
3
4
5
6
2
3
4
5
6
7
1
2
3
4
5
6
2
3
4
5
6
7
0.53
1.06
3.03
4.31
4.83
6.65
0.45
1.00
1.15
2.00
2.70
5.40
B.
0.53
1.06
3.03
4.31
4.83
6.65
0.45
1.00
1.15
2.00
2.70
5.40
83.1
84.1
91.6
88.8
88.8
92.5
70.6
82.3
83.3
84.0
81.4
82.3
OUTLIERS REMOVED
87.3
88.2
96.1
93.1
93.1
97.0
72.0
84.0
85.0
86.0
83.0
84.0
92.5
97.2
99.1
97.2
95.3
99.1
90.2
99.0
:96.1
95.1
94.1
92.2
95.1
98.0
100.0
99.0
97.0
100.0
91.0
99.0
97.0
96.0
95.0
93.0
97.2
99.1
99.1
98.1
97.2
99.1
94.1
99.0
99.0
99.0
97.1
94.1
100.0
99.0
100.0
99.0
98.0
100.0
95.0
99.0
99.0
99.0
97.0
95.0
100.0
100.0
100.0
100.0
99.1
100.0
97.1
100.0
100.0
100.0
97.1
91.1
100.0
100.0
100.0
100.0
99.0
100.0
97.0
100.0
100.0
100.0
97.0
96.0
28
-------
TABLE 20. AUDIT RESULTS FOR SULFUR DIOXIDE CONTINUOUS MONITORS (ALL DATA)
Flow
setting
1
2
3
4
5
6
Number of
reported
values*
32
242
255
255
253
181
Range of
values (ppm)
0.468 to 0.866
0.234 to 0.653
0.126 to 0.457
0.100 to 0.331
0.030 to 0.108
-0.006 to 0.060
Mean differences
ppm
-0.011
0.006
0.006
0.004
0.002
0.001
% diff.
-1.8
1.5
2.6
1.9
3.4
" "
Standard
deviation
(ppm)
0.060
0.036
0.027
0.016
0.007
0.005
*1985 Audit: Data returned for 257 monitors
TABLE 21. AUDIT RESULTS FOR SULFUR DIOXIDE CONTINUOUS
MONITORS BY VARIOUS INSTRUMENTAL METHODS
Flame photometric
Flow
setting
1
2
3
4
5
6
average difference
n
0
6
7
7
7
7
ppm
0.007
0.002
0.000
0.001
0.001
%
2.1
0.9
0.0
1.1
___
Fluorescent
average difference
n
31
231
243
243
242
169
ppm
-0.005
0.007
0.007
0.004
0.002
0.001
%
-1.0
1.6
2.8
2.1
3.5
___
Coulometric
average difference
n
0
4
4
4
4
4
ppm
-0.020
-0.002
0.0
0.0
0.004
%
-4.3
-0.7
-0.4
0.2
*..»_
29
-------
TABLE 22. PERCENT OF HI-VOL FLOW MEASUREMENTS WITHIN INDI-
CATED PERCENTAGE OF ASSIGNED VALUE (ALL DATA)
Plate
number
5
7
10
13
18
Number of
measurements
702
817
993
961
953
Approximate
flow (m3/min)
0.7
0.9
1.1
1.2
1.3
10%
68.8
78.2
84.1
86.5
88.7
20%
72.8
94.4
96.6
97.4
97.9
30%
96.4
97.6
98.7
99.2
99.2
50%
99.3
99.4
99.7
99.7
99.6
30
-------
TABLE 23. ACID RAIN RESULTS FOR pH, CONDUCTIVITY AND ACIDITY (ALL DATA)
Audit
0485 pH
Conductivity
US/cm)
Acidity
(pequiv/L)
1085 pH
Conductivity
(yS/cm)
Acidity
(yequiv/L)
Level
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
n
33
33
33
31
31
31
15
15
15
31
31
31
28
28
28
15
15
15
Assigned
value
4.39
4.00
3.56
20.20
53.10
134.30
44.50
107.70
293.00
4.29
3.92
3.19
24.70
61.60
322.20
54.60
129.00
677.10
Mean
4.32
3.93
3.51
20.57
52.63
131.35
60.71
131.49
375.39
4.25
3.89
3.21
25.91
62.08
330.36
70.93
150.10
668.14
% Ace.
-1.66
-1.78
-1.32
1.85
-0.89
-2.19
36.43
22.09
28.12
-0.91
-0.77
0.56
4.89
0.78
2.53
29.90
16.36
1.32
% CV
5.68
4.61
3.64
21.37
10.15
5.91
37.19
19.57
46.10
5.98
4.50
3.09
24.19
22.22
20.29
29.65
19.22
29.50
31
-------
TABLE 24. ACID RAIN RESULTS FOR pH, CONDUCTIVITY
AND ACIDITY (OUTLIERS REMOVED)
Audit
0485 pH
Conductivity
(yS/cm)
Acidity
(pequiv/L)
1085 pH
Conductivity
(yS/cm)
Acidity
(yequiv/L)
Level
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
1
2
3
n
31
31
31
30
30
31
15
15
14
29
30
30
27
27
27
14
15
14
Assigned
value
4.39
4.01
3.56
20.20
53.10
134.30
44.50
107.70
293.00
4.29
3.92
3.19
24.70
61.60
322.20
54.60
129.00
677.10
Mean
4.37
3.97
3.54
19.83
52.01
131.35
60.71
131.49
332.21
4.27
3.92
3.22
24.86
59.54
318.13
66.99
150.10
713.01
% Ace.
-0.36
-0.80
-0.51
-1.85
-5.82
-2.19
36.43
22.09
13.38
-0.54
-0.05
1.03
0.64
-3.34
-1.26
22.70
16.36
5.30
% CV
2.33
2.29
1.61
7.25
7.98
5.91
51.19
19.57
13.87
1.62
2.07
1.58
11.98
6.62
5.53
22.46
19.22
13.55
32
-------
TABLE 25. ACID RAIN AUDIT RESULTS FOR ANIONS (ALL DATA)
Audit Level
0485 S04 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
1085 S04 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
Assigned
n value (mg/1)
28
29
28
29
29
29
27
28
29
18
19
20
29
28
30
30
30
30
27
27
29
13
13
13
0.66
2.37
3.39
0.11
0.12
1.80
0.39
0.38
1.29
0.05
0.09
0.18
0.84
2.57
5.70
0.14
0.12
2.01
0.29
0.63
8.33
0.04
0.09
0.40
Mean
(mg/1)
0.89
2.83
3.53
0.12
0.19
1.80
0.71
0.70
1.61
0.05
0.09
0.17
1.05
3.05
5.92
0.16
0.13
2.23
0.33
0.65
8.08
0.04
0.09
0.41
% Ace.
34.44
19.24
4.01
8.18
62.93
0.00
81.22
86.97
24.65
-3.70
-3.37
-3.87
24.76
18.64
3.90
8.33
10.26
10.89
15.03
2.70
-2.99
-7.32
2.27
2.74
% CV
63.87
50.60
23.90
19.33
132.28
9.01
260.50
259.60
105.41
36.54
30.23
11.49
53.56
50.80
20.76
69.87
68.99
66.41
52.58
36.38
15.87
76.32
34.44
32.45
33
-------
TABLE 26. ACID RAIN AUDIT RESULTS FOR ANIONS (OUTLIERS REMOVED)
Audit Level
0485 S04 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
1085 304 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
n
26
27
26
28
27
28
26
27
28
17
18
19
27
28
28
29
29
29
25
24
28
12
12
11
Assigned
value (mg/1)
0.66
2.37
3.39
0.11
0.12
1.80
0.39
0.38
1.29
0.05
0.09
0.18
0.84
2.57
5.70
0.14
0.12
2.01
0.29
0.63
8.33
0.04
0.09
0.40
Mean
(mg/1)
0.77
2.50
3.50
0.12
0.12
1.77
0.36
0.36
1.31
0.05
0.09
0.18
0.92
2.66
5.63
0.14
0.11
1.97
0.29
0.62
8.25
0.03
0.10
0.41
% Ace.
16.54
5.18
3.10
5.45
6.89
-1.28
-9.39
-4.56
1.40
1.85
2.25
2.21
8.87
3.26
-1.21
-4.17
-3.42
-2.19
1.05
-1.59
-1.06
-21.95
11.36
1.49
% CV
44.16
28.14
10.78
15.52
31.45
6.03
28.10
32.31
40.29
36.54
17.58
11.49
28.07
13.05
20.76
25.36
27.43
16.78
35.29
12.76
15.87
50.00
16.33
7.35
34
-------
TABLE 27. ACID RAIN RESULTS FOR CATIONS (ALL DATA)
Audit Level
0485 NH3 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
1085 NH3 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
n
24
25
25
22
22
23
25
25
25
24
24
25
26
26
26
24
24
24
23
24
24
22
22
23
24
23
24
23
23
23
Assigned
value (mg/1)
0.08
0.61
0.89
0.05
0.06
0.05
0.09
0.08
0.08
0.02
0.01
0.04
0.19
0.25
0.40
0.08
0.63
0.66
0.05
0.14
3.60
0.07
0.09
5.43
0.02
0.01
0.35
0.18
0.24
0.50
Mean
(tng/1)
0.08
0.60
0.93
0.07
0.07
0.12
0.09
0.09
0.08
0.02
0.05
0.05
0.19
0.23
0.38
0.10
0.72
0.86
0.08
0.14
3.75
0.09
0.10
4.94
0.02
0.01
0.53
0.19
0.25
0.54
% Ace.
3.85
-1.63
3.46
37.04
28.07
133.96
1.16
10.13
4.00
5.26
420.00
17.95
1.03
-6.48
-5.74
30.00
15.47
31.35
52.00
2.86
4.05
16.22
14.44
-9.01
15.00
16.67
5.11
9.09
4.94
7.54
% CV
38.27
21.93
5.83
93.24
79.45
216.13
25.29
48.28
40.24
60.00
353.85
37.00
37.24
22.08
21.16
72.11
70.44
64.66
86.84
43.75
11.44
50.00
35.92
30.34
52.17
85.71
134.96
30.21
28.24
19.37
35
-------
TABLE 28. ACID RAIN AUDIT RESULTS FOR CATIONS (OUTLIERS REMOVED)
Audit Level
0485 NH3 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
1085 NH3 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
n
22
24
24
21
20
22
23
23
24
22
23
24
24
25
25
23
23
23
22
23
21
21
21
22
23
23
23
22
22
21
Assigned
value (mg/1)
0.08
0.61
0.89
0.05
0.06
0.05
0.09
0.08
0.08
0.02
0.01
0.04
0.19
0.24
0.40
0.08
0.63
0.66
0.05
0.14
3.60
0.07
0.09
5.43
0.02
0.01
0.35
0.18
0.24
0.50
Mean
(mg/1)
0.08
0.63
0.91
0.06
0.06
0.07
0.08
0.08
0.08
0.02
0.01
0.04
0.19
0.24
0.39
0.09
0.62
0.76
0.06
0.13
3.70
0.08
0.10
5.14
0.02
0.01
0.39
0.18
0.24
0.51
% Ace.
2.56
2.61
2.68
14.81
0.00
30.19
4.65
-2.53
-3.75
-10.53
40.00
10.26
-1.03
-2.43
-1.98
13.75
0.64
15.22
30.00
5.00
2.75
6.76
6.67
-5.34
5.00
0.00
9.94
3.41
-0.82
1.98
% CV
23.75
6.85
4.90
64.52
36.84
72.46
15.85
24.68
29.87
29.41
114.29
30.23
9.90
7.88
5.60
42.86
19.90
28.14
69.23
29.32
6.16
36.71
21.88
23.04
38.10
58.33
21.71
18.68
14.11
9.34
36
-------
TABLE 29. ACID RAIN AUDIT RESULTS FOR TRACE METALS (ALL DATA)
Audit
0485 Mn
Fe
Cd
Cu
Ni
Pb
Zn
1085 Mn
Fe
Cd
Cu
Ni
Pb
Zn
Level
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
n
15
16
15
15
14
15
15
15
12
12
15
15
16
16
16
15
14
14
15
15
17
16
13
13
16
16
15
15
Assigned
value (mg/1)
0.04
0.10
0.05
0.11
0.01
0.08
0.06
0.15
0.04
0.08
0.07
0.28
0.14
0.61
0.11
0.03
0.07
0.03
0.14
0.02
0.20
0.06
0.12
0.06
0.44
0.14
0.82
0.16
Mean
(mg/1)
0.04
0.10
0.06
0.11
0.02
0.07
0.05
0.14
0.04
0.08
0.06
0.27
0.14
0.61
0.11
0.03
0.08
0.03
0.14
0.02
0.21
0.06
0.12
0.05
0.40
0.11
0.84
0.16
% Ace.
-2.27
2.00
5.56
3.70
6.67
-6.58
-5.17
-1.36
2.50
2.50
-7.58
-3.93
1.41
0.33
-2.63
-6.25
11.43
11.11
0.73
13.64
2.96
1.79
2.48
-10.34
-8.22
-19.01
1.70
0.62
% CV
12.95
6.86
19.30
8.04
37.50
19.72
21.82
5.52
14.63
13.10
22.95
9.29
18.06
8.20
18.02
13.33
21.79
43.33
7.25
20.00
10.53
14.04
5.65
26.92
19.15
33.91
5.01
5.56
37
-------
TABLE 30. ACID RAIN AUDIT RESULTS FOR TRACE METALS (OUTLIERS REMOVED)
Audit
0485 Mn
Fe
Cd
Cu
Ni
Pb
Zn
1085 Mn
Fe
Cd
Cu
Ni
Pb
Zn
Level
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
4
5
n
14
15
14
14
13
14
14
15
11
11
14
14
15
15
15
14
14
13
15
14
16
16
13
12
15
15
14
15
Assigned
value (mg/1)
0.04
0.10
0.05
0.11
0.02
0.08
0.06
0.15
0.04
0.08
0.07
0.28
0.14
0.61
0.11
0.03
0.07
0.03
0.14
0.02
0.20
0.06
0.12
0.06
0.44
0.14
0.82
0.16
Mean
(mg/D
0.04
0.10
0.05
0.11
0.02
0.07
0.06
0.15
0.04
0.08
0.06
0.27
0.14
0.60
0.11
0.03
0.08
0.03
0.14
0.03
0.20
0.06
0.12
0.05
0.42
0.12
0.83
0.16
% Ace.
0.00
1.00
1.85
4.63
0.00
-2.63
0.00
-1.36
0.00
5.00
-3.03
-1.79
2.11
2.12
0.00
-6.25
11.43
0.00
0.73
18.18
0.49
1.79
2.48
5.17
-4.34
-13.38
0.85
0.62
% CV
11.36
4.95
14.55
7.07
13.33
13.51
12.07
5.52
7.50
10.98
12.50
4.73
11.51
3.84
14.91
13.33
21.79
37.04
7.25
15.38
6.37
14.04
5.65
16.36
9.31
21.14
5.01
5.56
38
-------
AVERAGE ACCURACY, percent
AVERAGE ACCURACY, percent
i
i i i t i i i i i
0)
a
o -m g
« 3 -
AVERAGE CV, percent
in 01 NI m _a a (\jujjrai
-------
AVERAGE ACCURACY, percent
i i i i i i
m ui -c uj r\j o f\juj-ccjim^im-DO
AVERAGE ACCURACY, percent
li
[Q
C
I
i
-
I *
O m B
c - =
5 i P
(Q
W
O
0!
-f
O"
o
3
o
CD
U
c
Q.
5-1
I
TJ >
3) -j
m m
O "
» 1
O 3
2 5
AVERAGE CV, percent
-------
Ttr
AVERAGE ACCURACY, percent
AVERAGE ACCURACY, percent
n |\J lij
CJl
0)
0)
a.
a
a
AVERAGE CV, percent
0)
rt-
to
Q)
a
3
AVERAGE CV, percent
ainaiauiacnatjio
-------
2
I.H -
I.E -
1.4 -
1.2 -
I -
O.B -
D.B -
D.4 -
D.Z -
D
-0.2 -
-Q.4 -
-D.B
D4/B3
I I/B3 D4/B4 ID/B4
ACCURACY
D4/BS
ID/BS
M
3.B
3.B
3.M -
3.2 -
3 -
Z.B -
2.6 -
2.4 -
2.2 -
2 -
I.B
I.E -
1.4 -
1.2 -
I
DH/B3
I I/B3
D4/B4 ID/B4
PRECISION
04/BS
id/as
Figure 7. Acid rain audit results for pH.
N>
I I/B3
D4/B4 ID/B4
ACCURACY
D4/BS
ID/BS
1 I/B3
Q4/B4
PRECISION
ID/B4
ICI/B5
Figure 8. Acid rain audit results for conductivity.
-------
AVERAGE ACCURACY, percent
AVERAGE ACCURACY, percent
CO
c
-I
CD
O
B)
C
a
ID
VI
AVERAGE CV, percenf
o
o
3
CD
a.
a>
at
V>
01
o
-------
I I/H3
Q4/BM i a/as
ACCURACY
D4/B5
ID/B5
II/B3 D4/B4 ID/B4
PRECISION
D4/B5
Figure 1 1 . Acid rain audit results for
(reported as N).
I I/B3
DM/B4 ID/BM
ACCURACY
DM/B5
ID/B5
I I/B3
D4/BM ID/84
PRECISION
04/85
ID/85
Figure 12. Acid rain audit results for Cl.
-------
I I/B3
DM/HH ID/B4
ACCURACY
D4/B5
in/as
04/B4 ID/84
PRECISION
04/85
IO/B5
Figure 13. Acid rain audit results for F.
in
I I/B3
DM/BM ID/B4
PRECISION
D4/B5
ID/B5
DM/B3
I I/B3
D4/B4
ACCURACY
IB/BM
Q4/BS
ID/BE
Figure 14. Acid rain audit results for NH4 (reported as IM).
-------
ma
10 -
BO -
70 -
60 -
50 -
40 -
30 -
ZO -
10 J
0
-10
04/H3
I I /B3 04/B4 I 0/B4
ACCURACY
04/B5
ID/B5
I I/B3
Q4/B4 IQ/SM
PRECISION
DM/85
Figure 15. Acid rain audit results for Ca.
B
7 -
E -
5 -
4 -
3 -
Z
I -
0
04/B3 I I/B3 D4/B4 10/B4
ACCURACY
04/BS
IO/B5
DH/BM IO/B4
PRECISION
m/as
Figure 16. Acid rain audit results for K.
-------
AVERAGE ACCURACY, percent
AVERAGE ACCURACY, percent
wi\jr\jr\J
to
c
o
a
01
a
AVERAGE CV, percent
(Q
C
O
a
5
5'
0)
c
a.
AVERAGE CV,
a
Ul
c_
r+
B>
s-
2
0)
CD
V>
c
-------
I I/B3
D4/B4 ID/B4
ACCURACY
Q4/B5
ID/BS
I I/B3
04/34 I Q/B4
PRECISION
ID/B5
Figure 19. Acid rain audit results for Mn.
oc
i
I I/B3
D^/B^ IQ/B4
ACCURACY
D4/BS
ID/B5
ID
D4/B3
I I/B3 04/64 ID/B4
PRECISION
ID/B5
Figure 20. Acid rain audit results for Fe.
-------
6*7
AVERAGE ACCURACY, percent
AVERAGE ACCURACY, percent
s
ca
c
<5
NJ
O
a
3
5'
01
c
a
*+
a
V)
c_
(A
-+i
O
O
AVERAGE CV, percent
c
a
ho
O
a
'
0)
c
a.
CD
in
c
O
a
AVERAGE CV, percent
-------
I I/B3
DM/H-i I0/B4
ACCURACY
D4/B5
ID/B5
I I/B3
DH/B4 ID/BM
PRECISION
ID/B5
Figure 23. Acid rain audit results for IMi.
I I/B3
D4/B4 i Q/B4
ACCURACY
D4/B5
ID/B5
IS -
ID
5 -
Q
D4/B3
I I/B3
04/BM ID/B4
PRECIS'ON
DM/85
ID/B5
Figure 24. Acid rain audit results for Pb.
-------
Ul >-'
-2
I I/B3
Q4/B4 ID/B4
ACCURACY
D4/BS
ID/BS
DH/aa
I I/H3
04/B4
PRECISION
DM/as
in/as
Figure 25. Acid rain audit results for Zn.
------- |