United States
Environmental Protection
Agency
Environmental Monitoring Systems
Laboratory
Research Triangle Park NC 27711
EPA-600/4-84-077
October 1984
Research and Development
rxEPA
National Performance
Audit Program
Ambient Air Audits of
Analytical Proficiency
1983
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NATIONAL PERFORMANCE AUDIT PROGRAM
AMBIENT AIR AUDITS OF ANALYTICAL PROFICIENCY
-1983-
by
Robert L. Lampe, Blaine F. Parr, 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 1983 National Audit Program by pollutant and by analytical method.
Semiannual audits were conducted for SC^ and NO2 (bubbler methods), Pb, NO3
and SO* (filter strips) and CO (continuous monitors). One audit was con-
ducted on high-volume flow rate. Continuous S02 monitors were audited
throughout the year, such that no monitor was audited more than once. This
was the first year that acid rain audits were conducted for U.S. laborator-
ies approximately 30 laboratories participated in each semiannual acid
rain audit. Twenty-four laboratories participated in each S0£ bubbler
audit, 28 in the 0683 N0£ audit, and 20 in the 1283 audit which represent
20-45Z_decreases from 1982 Fifty-nine laboratories participated in each of
the SO^ audits and approximately 50 in each of the NO^ audits. The 0183 Pb
audit had 103 participants and the 0783 had 92. Three hundred and ninety CO
monitors were checked in the 0383 audit and 361 in the 1083 audit. There
were 1447 high volume flow devices checked in the 0583 audit. Although
slight decreases in participation were noted for the SO^, NO^, Pb, CO
and flow audits, the total participation was still not markedly different
from 1982 levels.
iii
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CONTENTS
Page
Abstract ill
Tables v
Acknowledgments ...... vi
1. Introduction 1
2. Summary and Conclusions 3
3. Audit Materials 4
4. Audit Results ., 7
References ,, 13
Tables , 14
Figures 44
iv
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TABLES
Number
1 Agency Participation 14
2 Audit Results for Manual Sulfur Dioxide 15
3 Results for the Pararosaniline Method 16
4 Percent of Sulfur Dioxide Measurements Within
Indicated Percent of Assigned Values (Statistical
Outliers Removed) . ..... 17
5 Audit Results for Nitrogen Dioxide 18
6 Audit Results for Nitrogen Dioxide by the Sodium
Arsenite Method 19
7 Percentage of Nitrogen Dioxide Measurements Within
Indicated Percentage of Assigned Value (Statistical
Outliers Removed) 20
8 Audit Results for Carbon Monoxide 21
9 Audit Results for Carbon Monoxide by the NDIR and
GC Methods 22
10 Percentage of Carbon Monoxide Measurements Within
Indicated Percentage of Assigned Value (Statistical
Outliers Removed) 23
11 Audit Results for Sulfate on Filter Strips 24
12 Audit Results for Sulfate by the Manual Methods .... 25
13 Audit Results for Sulfate by the Automated Methods ... 26
14 Percentage of Sulfate Measurements Within Indicated
Percentage of Assigned Value (Statistical Outliers
Removed 27
15 Audit Results for Nitrate on Filter Strips 28
16 Audit Results for Nitrate by the Automated Methods ... 29
17 Percentage of Nitrate Measurements Within Indicated
Percentage of Assigned Value (Statistical Outliers
Removed) 30
18 Audit Results for Lead on Filter Strips 31
19 Percentage of Lead Measurements Within Indicated
Percentage of Assigned Value (Statistical Outliers
Removed 32
20 Audit Results for Sulfur Dioxide Continuous Monitors
(All Data) 33
21 Audit Results for Sulfur Dioxide Continuous Monitors
by Various Instrumental Methods 34
22 Audit Results for High-Volume Flow Rate 35
23 Acid Rain Results for pH, Conductivity and Acidity
(April 1983) 36
24 Acid Rain Audit Results for Anions (April 1983) .... 37
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TABLES (Con't.)
Number Pagt
25 Acid Rain Audit Results for Cations (April 1983) 38
26 Acid Rain Audit Results for Trace Metals (April 1983) ... 39
27 Acid Rain Results for pH, Conductivity and Acidity
(November 1983) 40
28 Acid Rain Results for Anions (November 1983) 41
29 Acid Rain Audit Results for Cations (November 1983) .... 42
30 Acid Rain Audit Results for Trace Metals (November 1983) . . 43
vi
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FIGURES
Mumber Page
1 SC>2 Bubbler Audits Accuracy 44
2 S02 Bubbler Audits Precision 45
3 N02 Bubbler Audits Accuracy 46
4 N02 Bubbler Audits Precision 47
5 Carbon Monoxide Audits Accuracy 48
6 Carbon Monoxide Audits Precision 49
7 Sulfate Audits Accuracy . 50
8 Sulfate Audits Precision 51
9 Nitrate Audits Accuracy 52
10 Nitrate Audits Precision 53
11 Lead Audits Accuracy 54
12 Lead Audits Precision 55
vil
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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 Berne Bennett, Linda Porter, Avis Hines and Dorothy
Drooz.
viii
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SECTION 1
INTRODUCTION
The 1983 ambient air audits of analytical proficiency, which were
managed by the Environmental Monitoring Systems Laboratory (EMSL), of the
U.S. Environmental Protection Agency (EPA), are a part of a continuing
audit program of six ambient air pollutants and high-volume samplers. In
1983, acid rain audits were added to the program. The program, entitled
the National Performance Audit Program, allows EPA to monitor the perform-
ance of laboratories making air pollution measurements and allows partici-
pating agencies to assess their performance with respect to other agencies.
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 solicited by the EPA Regional
Quality Control Coordinator in each of EPA's 10 regions. Agencies perform-
ing ambient air monitoring of criteria pollutants are required by Federal
regulation to participate. Once a laboratory enrolls in a particular audit,
it is automatically notified of subsequent audits of that pollutant. Parti-
cipants are assigned a permanent identifying code number. Federal, state,
local, industrial and foreign air pollution monitoring agencies participate
in the surveys.
Sample materials furnished for the audits are designed to 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.
Audits are presently conducted twice a year for carbon monoxide, sulfur
dioxide, nitrogen dioxide, lead, sulfate, nitrate and acid rain and once a
year for high-volume flow rate. Audits on S02 continuous monitors are con-
ducted throughout the year. At the end of the year, a comprehensive report
is prepared summarizing the audit results of that year. Each participant
is sent a copy of the report.
In addition, each laboratory participating in an audit receives an
evaluation of its performance shortly after the audit is completed. When
practical, laboratories submitting abnormally high or low results are
offered an opportunity to analyze another set of samples. However, the
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retest results are not Included in this summary report.
There are approximately 400 laboratories registered in the National
Performance Audit Program. This report presents the results of those labo-
ratories that participated in the 1983 audits. The category and number of
participants in each audit are presented in Table 1. With the exception of
the SC>2 monitor audit program which increased by 182, there was a general
decrease in participation in the 1983 audit program compared to the 1982
program: S02 bubbler method, 45Z; NO, bubbler method, 31Z; CO, 72; SO",
61; NOj, 21; Pb, 22, and high volume flow rate, 102.
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 manufac-
turer of the audit material.
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SECTION 2
SUMMARY AND CONCLUSIONS
The 1983 results closely parallel those of last year. With outliers
removed and values averaged, the percentage of results within 20 percent of
the assigned values ranged from a low of 83.6 (sulfate) to a high of 98.3
(CO). The overall average for all audits is 92.6 percent. This value is
slightly less than the 1982 value of 95.4 percent but still above the 90.3
percent average of the previous four years.1»2»3
The following percentage of results were rejected as outliers for each
type of audit: S02 bubbler (52), NO, bubbler (5.52), CO (1.32), SO^ (3.3%),
NOo (3.12), Pb (2.42), flow rate (4.62), SO, continuous (3.82) and acid
rain (5.12).
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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 N0£ samples in order to obtain
desired concentrations. Lead, NOj, and SO* 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
SO2 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 1983
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 S0£ in the
atmosphere. In the 1983 audits, the concentrations ranged frota approxi-
mately 21 to 220 vg of sulfur dioxide equivalent per cubic meter when
reconstituted properly. A sample set consisted of five different concen-
trations.
NITROGEN DIOXIDE (MANUAL)
Nitrogen dioxide samples consist of aqueous sodium nitrite solutions
that simulate ambient N02 samples collected by a 24-hour N0£ 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 0.4 to 1.0 ug/m£. A sample set consists of five different concen-
trations.
CARBON MONOXIDE
These audit materials consist of a mixture of CO, C02 and CH^ and zero
air in a pressurized gas cylinder that simulates an ambient air sample. The
concentrations of the three CO samples used in the 1983 audits ranged from
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6 to 44 ppm. Directions specify that the gas sample be introduced into a
continuous analyzer in the "sample" node, which permits the analyzer to
draw the sample in the sane fashion and at the same flow rate as during
ambient air nonitoring.
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 0.60 to
14.0 yg/m3 and sulfate from 1.0 to 30.0 yg/m3. Lead samples, which are
prepared from lead nitrate ranged in concentration from 0.58 to 8.0 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.
Each ReF device is calibrated with a positive displacement meter
before use. During use, 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
supplied with each unit, one as the pollutant source and the other for
dilution.
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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 0.00 to 0.864 ppm were used in the 1983 audits.
ACID RAIN
In 1982 an acid rain pilot study was conducted for U.S. participants
of the National Performance Audit Program (NPAP). Earlier acid rain audits
were generally limited to World Meteorological Organization members. This
pilot study proved beneficial and resulted in improvements in sample de-
sign, packaging and the data reporting form. For example, replacing the
glass vials with polyethylene bottles for the samples markedly improved sam-
ple stability.
In April 1983 the first "official" audit for U.S. participants was con-
ducted and in November a second audit was conducted. Approximately 30 lab-
oratories participated in each of these audits. Five samples each in poly-
ethylene bottles were shipped to each of the participating laboratories.
Three samples were analyzed for pH, conductivity, acidity and the major
cations and anions normally measured in precipitation samples. The other
two samples were analyzed for heavy metals. The latter two samples were
acid stabilized 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 were to analyze the samples
using the analytical procedures they normally employ when analyzing their
precipitation samples.
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SECTION 4
AUDIT RESULTS
The results of the 1983 audit are presented in Tables 2 through 30.
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,
laboratories or sites reporting values exceeding ± 20 percent of the as-
signed value, for all samples in a particular audit, have been excluded
from this report. These excluded values represent 5.2 percent of the total
number of laboratories or sites reporting results. Their values can be
largely attributed to malfunctioning equipment and/or inexperienced person-
nel and would unjustly affect the audit results. Second, rejection of
additional Individual results as outliers was based on Chauvenet's Crite-
rion.1*
In addition to the percentages of outliers determined by the two out-
lier procedures, it is desirable to derive some measures of overall perform-
ance of the participants after eliminating the outlier results. At each
audit level, the distribution of results from all participants Is surpris-
ingly normal in form when the outlier values are eliminated. This normal
distribution reflects some state of statistical control of the many vari-
ables influencing the results from the participants in the entire nation.
Further, the distributions1 of the percentages of deviations from the assign-
ed values are quite similar across audit levels for each pollutant. How
well the participants perform as a whole is reflected by the average and
variability of the percentage deviations.
At each audit level, the percent accuracy (X Ace.) and the precision,
as measured by the percent coefficient of variation (*CV), were computed as
follows:
X Ace. - audit median - EPA assigned value x JQO
EPA assigned value
1 CV - audit standard deviation x JQO
audit mean
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 participants.
For each pollutant measurement, it is desired to determine and report
a single measurement for "accuracy" and a single measurement for "preci-
sion." Because the results across audit levels are somewhat consistent,
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average accuracy and average precision values for each audit are computed.
These average values are plotted on Figures 1 through 12 to provide a way
of tracking trends over the history of the performance audit program. These
figures graphically demonstrate the continuing Improvement of participant
results since the inception of the program. These improvements are indirect
measures of the improvement in the quality of air pollutant measurements
made In the nation.
SULFUR DIOXIDE (BUBBLER)
Twenty-four laboratories participated in both the April (0483) and the
October (1083) audits. The percentage of local agency laboratories de-
creased during the 1983 audits. This decrease in participation has been
evident over the past few years due to the increasing number of laborator-
ies changing to automated analyzers.
The audit mean, percent accuracy and percent CV, with and without out-
liers, is reported In Tables 2 and 3. In Table 2 with the exception of the
third level, the mean value for all levels in the two audits exceeded the
assigned value. As usual the lowest precision and accuracy was achieved in
level one in both audits. The average percent accuracy appears to have
stabilized over the past three audits when compared to audits of previous
years (Figure 1). Precision improved in the 1982 audit and continued to
show improvement in the 1983 audits (Figure 2).
As shown in Table 3, part A, for the manual method, accuracy ranged
from -0.4 to 7.8 for all data and 0.8 to 8.2 after outliers were removed.
Accuracy for the automated method ranged from -2.5 to 8.1 with and without
the outliers. Concentrations did not appear to affect the precision for
the manual methods. However, some improvement can be noticed in the re-
sults by the automated method as concentrations increase (Table 3, part B).
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. With one exception, better than 87 percent of the measure-
ments fell within 20 percent of the assigned values, a greater percentage
than the previous year.
NITROGEN DIOXIDE
Participation decreased from 28 laboratories in the 0683 audit to 20
in the 1283 audit. Overall, total participation in the 1983 audits was 31%
less than in 1982. The decrease, which occurred among the state and local
participants, likely resulted because an increasing number of laboratories
are replacing bubblers with continuous analyzers.
The audit mean, percent accuracy and percent CV with and without out-
liers is reported in Tables 5 and 6. The accuracy (Figure 3) in the 0683
audit was not as good as those of the 1982 audits. In the 1283 audit
accuracy improved. The bias over the past several years seemed to vary
from audit to audit and more recently from year to year. The last five
audits show improvement and a leveling off in precision (Figure 4). With
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few exceptions the precision and accuracy over the years has been good.
Table 7 shows that approxlnately 95 percent of the laboratories were
within ± 102 of the assigned values and better than 97Z were within ± 20 per-
cent. Although these percentages are above the averages for the past few
years, they are not equal to those attained In 1982 when 100Z of the values
were within ± 20% and with two exceptions were within ± 102.
CARBON MONOXIDE
The number of monitors being audited Increased from 552 in 1977 to a
high of 793 in 1982. In 1983 a total of 751 monitors were audited a 52
decrease from 1982. There has been little change in the number of sites over
the past three years. The percent age of state, local and foreign sites
being audited has increased slightly since 1982 and the percentage of in-
dustrial and federal sites has decreased slightly. The percent accuracy
and percent CV are shown in Table 8. Precision and accuracy in the first
1983 audit improved compared to the first 1982 audit; however, the reverse
occurred in the second audit in those years.
When the percent accuracy and percent CV are averaged for each audit
(see Figures 5 and 6), there is noticeable improvement beginning with the
1980 audits up to the present. Prior to 1980, the variations in precision
and accuracy were wider.
As shown in Table 9, the NDIR method continues to show greater accu-
racy and precision than the GC method. Although a few participants use
other methods such as gas filter correlation and electrochemical, but too few
to make a meaningful comparison.
With the exception of the lowest level in the 1083 audit the number of
measurements falling within 202 of the assigned value closely parallels the
1982 results (Table 10).
SULFATE ON FILTER STRIPS
Approximately 60 laboratories participated in each of the audits. This
is about 6 percent fewer than last year. There were less local agencies
participating this year than last. In general, participation in SO^ audits
seems to have reached a plateau over the past several years.
The audit mean percent accuracy and precision are given in Table 11.
Accuracy over the years (1976-1983) varied quite a bit usually on the posi-
tive side with the best years being 1977 and 1982 (Figure 7). Precision
also varied during the period (Figure 8), but showed improvement in the 0282,
0882, and 0283 audits.
In general for the 1983 audits, the percent accuracy and precision for
the manual methods (Table 12) improve as sample concentrations increase.
With outliers removed the Sulfa-ver method indicates a negative bias in the
0283 audit. A positive bias prevailed in the other audits this year and
last where this method was employed. For the automated methods, with excep-
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tion of the 0883 audit, both the Thymol Blue and the Ion Chromatograph show
a larger negative bias for this year compared to 1982 (Table 13). Sample
concentration does not seem to affect the precision and accuracy of the
automated methods as it does in the manual methods.
Except for the lowest sample concentration, between 84 and 97 percent
of the laboratories reported results within ± 20 percent of Uhe assigned
values (Table 14). These results compare favorably with the 1982 audits.
NITRATE ON FILTER STRIPS
There were approximately 50 laboratories taking part in each of the
1983 audits. Participation was down approximately 2 percent from the 1982
audits, mainly because there were fewer industrial participants. Since
1978 the number of participants has been fairly consistent, indicating that
a plateau has been reached similar to that in sulfate audits.
In general, accuracy (Figure 9) varied widely from 1976 through 1981.
Variation in the last four audits has been small, however, indicating some
improvement. The precision chart (Figure 10) shows two periods of improve-
mentone from August 1978 through August 1979; the other from February 1982
through August 1983. Both periods coincide with those times when accuracy
showed some improvement.
A negative bias is apparent in the 0283 audit. Previously, the only
negative bias appeared in the 1979 audits.
Results from all methods together (Table 15) show slight improvement
over the 1982 audits. For the automated methods tabulated in Table 16, the
accuracy for the ion chromatograph method is not as good as the 1982 audits;
however, the precision has improved. The cadmium reduction method shows
definite improvement for both the accuracy and precision over the 1982
results.
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 HAS 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 was very close to those reported for 1982. When averaged they were
almost identical. For the lowest concentration there was noticeable im-
provement in the percentage of values that fell within the ± 20 percent of
the assigned value.
LEAD ON FILTER STRIPS
One hundred and three laboratories participated in the 0183 audit and
92 in the 0783, 2 percent less than in the 1982 audits. The decrease was
due to a smaller number of participants among the state and industrial lab-
oratories. Participation has leveled off in the past three years and aver-
ages between 95 and 100 laboratories for each of the audits.
10
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The audit nean, percent accuracy and percent CV are shown In Table 18.
Accuracy was better in the 0183 than in the 0182 but the reverse is true in
the 0782 and 0783 audits. Both of the audits in 1983 show Improvement in
precision over the 1982 audits. Since 1977, with two exceptions, accuracy
has been with 2 percent and usually on the negative side. Precision Im-
proved after the first two audits and with one exception has been within
± 8 percent since 1979 (see Figures 11 and 12).
In 1983 the number of measurements within ± 20 percent of the assigned
value was slightly less than in the 1982 audits (Table 19). With the excep-
tion of two laboratories using the inductively coupled argon plama optical
emission spectrometric method, all others used the atomic absorption method.
SULFUR DIOXIDE (CONTINUOUS MONITORS)
The number of laboratories participating in the 1983 audits totaled 86.
The number of individual monitors audited was 187 (Table 20). Compared to
1982 this is an overall increase of approximately 18 percent, mainly be-
cause of increased participation among state agencies.
The methods most commonly used were: fluorescence (157), flame photo-
metric (22) and coulometric (6). The accuracy for each of the methods is
shown in Table 21. With one exception the accuracy of the fluorescent and
the coulometric methods showed improvement over the 1982 results. Overall
the mean percent difference has improved each year since 1981. The greatest
improvement in 1983 occurred with the coulometric method.
HIGH VOLUME
There were 216 agencies participating in the audit with an average of
6.2 sites per agency. The number of monitors checked this year is 10 per-
cent below the number for 1982. Prior to this year there had been an in-
crease every year in the number of monitors audited beginning with 1977.
The decrease is a result of the drop in the number of industrial and fed-
eral agencies taking part in the program this year.
The pressure transducer continued to be the most widely used method of
measurement (50.92), the rotometer was next (27.5%), followed by pressure
transducer/flow controller (2.82) and flow controller (2.72). Other methods
accounted for the remaining 16.1 percent of the results and included: ori-
fice manometer, manometer, flow gauge, and pressure transducer/non-contin-
uous. The results (Table 22) were little changed from 1982. For example
in 1983, 402 of the rotameters yielded results within 2.42 of the true value,
whereas, in 1982 402 of them yielded results within 2.22 of the true values.
ACID RAIN
Twenty-eight laboratories participated in the 0483 audit and thirty-
two in the 1183 audit. The greatest percentage of laboratories participat-
ing were state operated followed by Industrial, federal and local labora-
tories.
11
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The audit mean, percent accuracy and percent CV for samples 1,2 and 3
are presented in Tables 23, 24 and 25 for the 0483 audit and Tables 27, 28
and 29 for the 1183 audit. For most of the constituents in these samples
the percent accuracy was better in the 1183 audit than in the 0483, but the
reverse was true for precision.
The accuracy and precision values are not as reliable for the trace
etals in samples 4 and 5 (Tables 26 and 30). The concentrations in these
samples are low and a small change in concentration results in a large
relative (percentage) change.
In general, for all samples, the percent accuracy and percent CV were
better in the 0483 audit than in the 1183 audit.
12
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REFERENCES
1. Lampe, R.L., Parr, B.F., Bennett, B.I., Pratt, G. and Mitchell, U.J.
National 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.
2. Bennett, B.I., R.L. Lampe, L.F. Porter, A.P. Hines and J.C. Puzak.
National Performance Audit Program. Ambient Air Audits of Analytical
Proficiency, 1981. U.S. Environmental Protection Agency Report EPA
600/4-83-009. Research Triangle Park, North Carolina 27711. April
1983.
3. Rhodes, R.C., B.I. Bennett and J.C. Puzak. EPA's National Perform-
ance Audit Program for Ambient Air Pollution Measurements. In: Pro-
ceedings of the 75th Annual Meeting of the Air Pollution Control
Association, New Orleans, Louisiana, 1982. 82-23,7:1-18.
4. Chauvenet, W. A Manual of Spherical and Practical Astronomy. J.B.
Lipincott and Company, Philadelphia, Pennsylvania, 1863. pp. 558-566.
13
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TABLE I. AGENCY PARTICIPATION
Distribution (%)
Survey
S02 April 1983
S02 October 1983
N02 June 1983
N02 December 1983
CO May 1983
CO October 1983
S04 February 1983
804 August 1983
N03 February 1983
N03 August 1983
Pb January 1983
Pb July 1983
S02 (continuous)
High-Volume Flow-Rate
May 1983
Acid Rain April 1983
Acid Rain November 1983
States
29.2
29.2
32.1
25.0
41.4
44.2
47.5
42.4
54.5
50.0
41.0
41.3
59.0
34.9
50.0
43.8
Local
29.2
29.2
46.4
45.0
46.9
41.3
18.6
23.7
20.5
23.8
30.0
26.0
26.0
47.5
7.1
6.2
Industry
37.5
37.5
21.4
30.0
7.3
8.8
20.3
22.0
13.6
14.3
26.0
26.0
14.0
14.8
28.6
37.5
Federal
4.2
4.2
0.0
0.0
1.3
1.7
3.0
3.4
2.0
2.4
2.0
3.2
1.0
0.6
14.3
12.5
Foreign
0.0
0.0
0.0
0.0
3.1
4.0
5.0
8.5
9.0
9.5
1.0
3.2
0.0
2.2
NA
NA
No. of
Laboratories9
24 (0)
24 (0)
28 (0)
20 (0)
59 (2)
59 (0)
44 (7)
42 (6)
100 (3)
92 (0)
28
32
No. of
Monitors*
__
386 (4)
351 (10)
187
1342 (105)
aValue In parentheses is the number of laboratories/monitors that reported all values off by more than ± 20%
from the true value.
-------
TABLE 2. AUDIT RESULTS FOR MANUAL SULFUR DIOXIDE
Audit
0483
1083
0483
1083
Level
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
n
24
23
24
24
24
24
23
24
24
24
B.
22
22
23
23
24
22
22
23
22
23
Assigned
value (wg/n3)
A. ALL DATA
21.60
55.60
105.2
153.1
220.0
48.80
81.90
122.0
154.50
178.50
Mean
(wg/m3)
21.27
55.85
103.3
151.9
224.4
49.74
83.53
124.09
161.78
181.53
Z Ace.
6.1
1.1
-0.4
0.8
2.8
2.7
2.0
3.3
5.7
1.3
X CV
28.2
10.3
9.7
8.4
5.5
11.1
10.6
12.4
10.8
8.9
STATISTICAL OUTLIERS REMOVED
21.60
55.60
105.2
153.1
220.0
48.80
81.90
122.0
154.50
178.50
22.40
56.55
104.5
153.5
224.7
50.93
84.40
126.48
162.49
179.66
6.2
1.2
-0.7
0.9
2.8
3.1
2.1
3.4
5.7
1.3
18.3
8.3
7.9
6.8
5.5
7.8
9.3
8.0
6.3
7.8
15
-------
TABLE 3. RESULTS FOR THE PARAROSANILINE METHOD
Manual Method (01)
Audit
0483
1083
Level
1
2
3
4
5
1
2
3
4
5
Assigned
value
(Ug/m3)
21.60
55.60
105.20
153.10
220.00
48.80
81.90
122.00
154.50
178.5
n
15
14
15
15
15
16
16
16
16
16
Mean
(Mg/m3)
20.31
55.29
103.16
153.76
224.83
50.49
85.84
125.65
164.40
184.32
Z Ace.
A. ALL
1.9
0.0
-0.4
0.8
3.4
3.3
4.0
5.5
7.8
3.3
% CV
DATA
35.6
12.0
11.5
9.9
6.4
11.1
11.6
14.4
12.5
9.6
B. STATISTICAL OUTLIERS
0483
1083
1
2
3
4
5
1
2
3
4
5
21.60
55.60
105.20
153.10
220.00
48.80
81.90
122.00
154.50
178.5
15
13
14
14
15
15
15
15
15
14
20.31
56.47
105.14
153.76
224.83
51.41
87.45
129.42
168.30
184.22
1.9
1.1
1.4
0.8
3.4
3.5
5.4
6.0
8.2
3.3
35.6
9.2
8.9
1.1
6.4
8.9
8.6
7.9
8.2
6.1
Automated
n
8
8
8
8
8
7
7
7
7
7
REMOVED
8
8
8
8
8
7
7
7
7
6
Mean
(pg/m3)
23.39
57.43
104.90
154.87
223.73
48.50
78.64
120.02
154.80
174.90
23.39
57.43
104.90
154.87
223.73
48.50
78.64
120.02
154.80
179.62
Method (02)
Z Ace.
8.1
4.6
1.3
1.3
2.3
2.0
-2.5
-2.0
1.1
0.4
8.1
4.6
1.3
1.3
2.3
2.0
-2.5
-2.0
1.1
0.5
Z CV
5.3
6.4
5.2
4.8
4.0
12.1
7.5
7.0
3.8
7.2
5.3
6.4
5.2
4.8
4.0
12.1
7.0
7.0
3.8
1.1
-------
TABLE 4. PERCENT OF SULFUR DIOXIDE MEASUREMENTS WITHIN INDICATED
PERCENT OF ASSIGNED VALUES (ALL DATA)a
Audit
0483
1083
Level
1
2
3
4
5
1
2
3
4
5
Assigned
value (yg/m3)
21.60
55.60
105.20
153.10
220.00
48.80
81.90
122.00
154.50
178.50
10Z
58.3
75.0
83.3
87.5
87.5
62.5
58.3
70.8
79.2
83.3
20Z
75.0
87.5
91.7
95.8
100.0
87.5
87.5
91.2
87.5
95.8
30Z
79.2
95.8
100.0
100.0
100.0
100.0
95.8
95.8
91.7
100.0
50Z
91.2
95.8
100.0
100.0
100.0
100.0
95.8
100.0
100.0
100.0
Percentage difference table unchanged after outliers deleted.
17
-------
TABLE 5. AUDIT RESULTS FOR NITROGEN DIOXIDE
Audit
0683
1283
0683
1283
Level
0
1
2
5
8
3
4
6
7
9
0
1
2
5
8
3
4
6
7
9
n
28
28
28
28
27
19
19
20
20
20
B.
27
26
27
26
26
17
18
19
19
19
Assigned
value ( pg/ml)
A. ALL DATA
0.415
0.548
0.645
0.553
0.936
0.515
0.790
0.640
0.480
1.000
Mean
0.396
0.543
0.616
0.527
0.897
0.512
0.791
0.656
0.483
1.046
X Ace.
-4.1
0.4
-4.2
-4.5
-4.1
-1.4
0.0
2.3
0.0
4.6
X CV
4.8
5.7
3.9
3.4
2.0
3.5
2.9
3.5
4.3
2.7
STATISTICAL OUTLIERS REMOVED
0.415
0.548
0.645
0.553
0.936
0.515
0.790
0.640
0.480
1.000
0.399
0.550
0.619
0.527
0.895
0.507
0.787
0.652
0.480
1.050
-3.9
0.5
-4.0
-4.5
-4.3
-1.6
0.0
2.2
0.0
4.8
3.3
2.2
2.3
2.3
1.7
2.0
2.2
2.6
2.9
2.2
18
-------
TABLE 6. AUDIT RESULTS FOR NITROGEN DIOXIDE BY THE SODIUM ARSENITE METHOD
Manual Method (05)
Audit
0683
1283
0683
1283
Level
0
1
2
5
8
3
4
6
7
9
0
1
2
5
8
3
4
6
7
9
Assigned
value
(pg/»L)
0.415
0.548
0.645
0.553
0.936
0.515
0.790
0.640
0.480
1.000
0.415
0.548
0.645
0.553
0.936
0.515
0.790
0.640
0.480
1.000
n
18
18
18
18
17
11
10
11
11
11
B.
17
17
17
17
16
10
10
10
11
10
Mean
(pg/mL)
A.
0.395
0.544
0.615
0.528
0.900
0.510
0.788
0.647
0.480
1.042
Z Ace.
ALL DATA
-1.7
0.5
-3.9
-4.5
-4.1
-1.6
0.0
1.4
0.0
4.8
STATISTICAL OUTLIERS
0.399
0.550
0.621
0.525
0.897
0.506
0.788
0.647
0.480
1.049
-3.9
0.7
-3.7
-4.7
-4.1
-2.3
0.0
0.9
0.0
4.9
Z CV
5.6
5.7
4.6
4.0
2.0
3.5
2.8
2.8
3.5
3.3
REMOVED
3.5
2.1
2.0
3.0
1.6
2.4
2.8
1.7
3.5
2.4
n
7
7
7
7
7
5
6
6
6
6
7
7
7
7
7
5
6
6
6
6
Automated
Mean
(pg/nL)
0.400
0.547
0.617
0.528
0.891
0.517
0.798
0.659
0.491
1.041
0.400
0.547
0.617
0.528
0.891
0.517
0.798
0.659
0.491
1.041
Method (06)
Z Ace.
-4.1
-0.7
-4.7
-4.3
-4.8
-0.2
-0.3
2.0
0.6
4.1
-4.1
-0.7
-4.7
-4.3
-4.8
-0.2
-0.3
2.0
0.6
4.1
Z CV
2.8
2.6
1.9
1.8
2.2
4.6
3.6
5.3
6.3
1.2
2.8
2.6
1.9
1.8
2.2
4.6
3.6
5.3
6.3
1.2
-------
TABLE 7. PERCENTAGE OF NITROGEN DIOXIDE MEASUREMENTS WITHIN INDICATED
PERCENTAGE OF ASSIGNED VALUE (ALL DATA)a
Audit
0683
1283
Level
0
1
2
5
8
3
4
6
7
9
Assigned
value (uR/«L)
0.42
0.55
0.65
0.55
0.94
0.52
0.79
0.64
0.48
1.00
10Z
92.9
92.9
96.4
96.4
96.4
95.0
95.0
95.0
95.0
100.0
202
96.4
96.4
96.4
100.0
96.4
95.0
95.0
100.0
100.0
100.0
30Z
100.0
100.0
100.0
100.0
96.4
95.0
95.0
100.0
100.0
100.0
50Z
100.0
100.0
100.0
100.0
96.4
95.0
95.0
100, J
100.0
100.0
Percentage distribution table unchanged after outliers removed.
20
-------
TABLE 8. AUDIT RESULTS FOR CARBON MONOXIDE
Audit
Level
n
Assigned
value (ppm)
Mean
(ppm)
Z Ace.
Z CV
A. ALL DATA
0583 1 386 6.10 6.00 -1.6 9.2
2 380 21.50 21.59 0.3 2.1
3 384 44.00 44.33 0.6 2.6
1083 1 345 8.30 8.36 1.2 8.0
2 352 15.86 16.14 1.5 6.1
3 351 36.76 37.33 1.1 5.3
B. STATISTICAL OUTLIERS REMOVED
0583 1 381 6.10 5.97 -1.6 6.0
2 375 21.50 21.58 0.3 2.8
3 380 44.00 44.30 0.6 2.4
1083 1 341 8.30 8.35 1.2 5.5
2 351 15.86 16.14 1.5 3.7
3 348 36.76 37.20 1.1 2.8
21
-------
TABLE 9. AUDIT RESULTS FOR CARBON MONOXIDE BY THE NDIR AND GC METHODS
K)
N)
Audit
Level
Assigned
value (ppm)
NDIR (9)
n Mean (ppm)
% Ace.
Z CV
n
A. ALL DATA
0583
1083
0583
1083
1
2
3
1
2
3
1
2
3
1
2
3
6.10
21.50
44.00
8.30
15.86
36.76
6.10
21.50
44.00
8.30
15.86
36.76
367
361
365
324
330
329
B.
363
356
360
319
325
326
6.00
21.58
44.30
8.36
16.13
37.28
STATISTICAL
5.97
21.59
44.31
8.39
16.15
37.24
-1.6
0.3
2.7
1.2
1.8
1.2
OUTLIERS
-1.6
0.4
0.7
1.2
1.8
1.2
8.8
3.2
2.7
6.0
3.5
3.2
REMOVED
5.9
2.7
2.3
4.8
3.2
2.7
6
6
6
3
3
3
6
6
6
3
3
3
GC (10)
Mean (ppm)
5.23
20.59
43.67
7.08
14.62
36.35
5.23
20.59
43.67
7.08
14.62
36.35
% Ace.
-13.0
-2.5
-1.0
-17.0
-8.8
0.1
-13.0
-2.5
-1.0
-17.0
-8.8
0.1
Z CV
11.1
6.4
1.1
8.1
2.3
2.5
11.1
6.4
1.1
8.1
2.3
2.5
-------
TABLE 10. PERCENTAGE OF CARBON MONOXIDE MEASUREMENTS WITHIN INDICATED
PERCENTAGE OF ASSIGNED VALUE
Assigned
Audit Level value (ppm) 102 202 302 502
0383 1
2
3
1083 1
2
3
A. ALL DATA
0583 1 6.10
2 21.50
3 44.00
1083 1 8.30
2 15.86
3 36.76
88.2
95.9
97.7
89.8
93.9
95.6
97.9
98.5
99.5
93.9
98.1
97.8
98.5
98.5
99.5
96.7
98.9
98.6
99.2
98.5
99.5
97.5
99.4
98.9
B. STATISTICAL OUTLIERS REMOVED
6.10
21.50
44.00
8.30
15.86
36.76
89.1
96.9
98.7
92.3
96.6
98.3
96.7
98.4
99.5
96.0
100.0
99.1
98.7
98.4
99.5
97.4
100.0
99.7
99.5
98.4
99.5
98.0
100.0
99.7
23
-------
TABLE 11. AUDIT RESULTS FOR SULFATE ON FILTER STRIPS
Audit
0283
0883
0283
0883
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
n
56
58
59
59
59
58
55
59
59
58
59
58
B.
54
55
57
57
57
57
53
58
57
56
57
56
Assigned
value (pg/in3)
A. ALL DATA
1.20
3.64
7.24
12.01
19.30
23.90
2.62
4.49
8.96
12.82
21.23
28.51
STATISTICAL OUTLIERS
1.20
3.64
7.24
12.01
19.3
23.90
2.62
4.49
8.96
12.82
21.23
28.51
Mean
(yg/n3)
1.49
3.53
7.24
11.72
18.31
22.48
2.50
5.04
9.03
12.89
21.06
28.49
REMOVED
1.37
3.53
7.10
11.73
18.40
22.74
2.12
4.61
8.84
12.93
21.05
28.25
Z Ace.
1.7
-3.8
-3.5
-3.3
-4.2
-5.0
-23.2
-0.9
-2.9
-0.2
-0.8
-0.3
0.0
-3.8
-3.6
-3.3
-4.2
-4.6
23.7
-l.l
-2.9
-0.2
-0.8
-0.4
2 CV
55.7
18.9
14.9
14.8
11.2
10-°
88.8
71.2
14.0
10.9
6.6
6.7
41.6
11.8
10.6
8.8
6.3
6.6
46.2
30.8
8.5
7.5
5.3
5.2
24
-------
TABLE 12. AUDIT RESULTS FOR SULFATE BY THE MANUAL METHODS
Audit
Level
Assigned
value
(pg/m3)
n
BaCI?
Mean
(ug/m3) Z
(17)
Ace.
Sulfa-Ver (19)
% CV
n
Mean
(yg/m3)
% Ace.
Z CV
A. ALL DATA
0283
0883
0283
0883
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1.20
3.64
7.24
12.01
19.30
23.90
2.62
4.49
8.96
12.82
21.23
28.51
1.20
3.64
7.64
12.01
19.30
23.90
2.62
4.49
8.96
12.82
21.23
28.51
8
9
9
9
9
8
8
10
10
10
10
9
B.
8
9
9
9
8
8
7
9
9
9
9
8
2.38
3.76
7.75
12.64
19.30
22.82
3.79
5.48
9.56
13.59
21.78
29.74
STATISTICAL
2.38
3.76
7.75
12.64
18.64
22.82
2.66
4.71
8.99
13.18
21.33
28.51
45.8
4.4
6.2
3.2
-2.6
-0.2
-5.7
0.4
0.4
3.0
0.8
2.8
OUTLIERS
45.8
4.4
6.2
3.2
-2.8
-0.2
-6.1
0.2
0.6
2.7
0.2
1.6
61.3
32.7
19.6
10.2
11.8
4.2
97.1
51.3
22.0
10.7
7.7
7.1
REMOVED
61.3
32.7
19.6
10.2
6.3
4.2
74.1
31.2
12.6
5.6
4.3
2.3
5
5
5
5
5
5
3
4
4
4
4
4
5
5
5
5
5
5
3
4
4
4
4
4
1.65
4.03
7.08
12.01
17.74
21.46
2.24
5.52
10.50
14.10
20.91
28.96
1.65
4.03
7.08
12.01
17.74
21.46
2.24
5.52
10.50
14.10
20.91
28.96
13.3
6.6
-7.5
-9.7
-9.1
-7.9
-19.8
6.4
8.4
6.6
-0.4
-0.6
13.3
6.6
-7.5
-9.7
-9.1
-7.9
-19.8
6.4
8.4
6.6
.0.4
0.6
57.0
29.0
18.6
18.8
5.2
7.3
23.2
32.2
25.4
12.7
6.2
15.5
57.0
29.0
18.6
18.8
5.2
7.3
23.2
32.2
25.4
12.7
6.2
15.5
-------
TABLE 13. AUDIT RESULTS FOR SULFATE BY THE AUTOMATED METHODS
Methyl Thymol Blue (16)
Audit
0283
0883
Level
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value
(Ug/m3)
1.20
3.64
7.24
12.01
19.30
23.90
2.62
4.49
8.96
12.82
21.23
28.51
n
25
25
26
26
26
26
25
24
25
24
25
25
Mean
(pg/m3)
A.
1.34
3.48
7.05
11.28
17.95
22.04
2.48
5.46
8.88
12.62
21.09
28.35
% Ace.
ALL DATA
0.0
-5.5
-5.7
-4.5
-4.4
-5.3
-25.2
-1.1
-2.9
-0.2
-0.1
-1.1
% cv
40.3
13.2
10.8
14.6
14.2
14.5
100.0
96.0
7.2
12.0
7.0
3.3
n
16
17
17
17
17
17
16
18
17
17
17
17
Ion Chromatograph (34)
Mean
(pg/m3)
1.14
3.48
7.29
12.07
18.52
23.20
1.91
4.19
8.59
12.47
20.82
28.20
Z Ace.
-0.8
-3.6
-3.5
-2.4
-3.8
-3.8
-24.8
-1.8
-3.7
-1.3
-1.3
-2.8
z cv
25.4
8.0
16.6
11.6
6.4
7.4
21.5
21.7
5.1
5.7
5.3
6.2
B. STATISTICAL OUTLIERS REMOVED
0283
0883
1
2
3
4
5
6
1
2
3
4
5
6
1.20
3.64
7.24
12.01
19.30
23.90
2.62
4.49
8.96
12.82
21.23
28.51
25
24
25
25
25
25
24
23
25
23
23
25
1.34
3.44
6.97
11.57
18.39
22.60
2.02
4.40
8.88
12.90
21.43
28.35
0.0
-6.1
-5.7
-4.2
4.2
-5.2
23.3
-1.3
-2.9
-0.2
0.0
-1.1
40.3
11.9
9.6
6.3
6.7
6.2
44.1
10.0
7.2
5.7
4.2
3.3
15
16
16
16
16
16
15
17
16
16
17
16
1.21
3.43
7.00
11.63
18.36
23.49
1.99
4.40
8.67
12.57
20.82
28.46
0.0
-3.8
-3.7
-2.7
-4.0
-2.6
-24.8
-1.3
-3.3
-0.9
-1.3
-0.3
12.4
6.4
3.9
5.4
5.4
3.5
12.1
5.9
3.8
4.8
5.3
5.0
-------
TABLE 14. PERCENTAGE OF SULFATE MEASUREMENTS WITHIN INDICATED PER
CENTAGE OF ASSIGNED VALUE
Audit
0283
0883
Level
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value (yg/nr)
A.
1.20
3.64
7.24
12.01
19.30
22.68
2.62
4.49
8.96
12.82
21.23
28.51
10Z
ALL DATA
36.1
52.5
63.9
77.0
75.4
77.0
13.6
67.8
79.7
79.7
89.8
89.8
B. STATISTICAL OUTLIERS
0283
0883
1
2
3
4
5
6
1
2
3
4
5
6
1.20
3.64
7.24
12.01
19.30
22.68
2.62
4.49
8.96
12.82
21.23
28.51
39.2
55.1
66.1
79.7
78.0
81.0
13.6
67.8
79.7
79.7
89.8
89.8
20Z
54.1
80.3
85.2
90.1
91.8
88.5
25.4
86.4
93.2
93.2
96.6
94.9
REMOVED
58.9
84.5
88.1
91.8
96.9
93.1
25.4
86.4
93.2
93.2
96.6
94.9
302
62.3
88.5
91.8
95.1
96.7
95.1
54.2
91.5
94.9
94.9
100.0
98.3
67.9
93.1
94.9
96.7
98.3
98.3
54.2
91.5
94.9
94.9
100.0
98.3
50Z
70.5
90.2
93.4
95.1
96.7
95.1
76.3
91.5
96.6
96.6
100.0
98.3
76.8
94.8
96.7
96.7
98.3
98.3
76.3
91.5
96.6
96.6
100.0
98.3
27
-------
TABLE 15. AUDIT RESULTS FOR NITRATE ON FILTER STRIPS
Audit
0283
0883
0283
0883
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
n
43
43
44
44
44
43
39
42
42
42
42
42
B.
42
42
42
42
43
41
38
39
41
42
41
41
Assigned
value (ug/n3)
A. ALL DATA
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.06
8.75
11.09
13.63
STATISTICAL OUTLIERS
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.06
8.75
11.09
13.63
Mean
(gg/m3)
0.81
2.46
5.62
9.29
11.59
13.93
0.70
1.90
5.08
8.73
11.76
13.56
REMOVED
0.77
2.40
5.61
9.31
11.56
13.72
0.67
1.80
5.05
8.77
11.12
13.63
Z Ace.
0.0
-0.4
-1.9
-1.9
-2.3
-1.4
3.3
1.1
-0.8
0.6
1.0
-1.0
-.1.3
-1.3
-1.9
-1.9
-2.3
-1.6
3.3
0.6
-1.0
0.6
0.5
-0.9
Z CV
39.5
20.7
10.3
8.7
6.6
9.1
34.3
23.7
7.3
6.2
5.2
6.3
31.2
14.2
6.8
6.6
5.3
5.7
25.4
13.9
6.7
6.2
4.7
5.4
28
-------
TABLE 16. AUDIT RESULTS FOR NITRATE BY THE AUTOMATED METHODS
N>
VO
Ion Chromatograph (34)
Audit
0283
0883
0283
0883
Level
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
I
2
3
4
5
6
Assigned
value
(yg/m3)
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.06
8.75
16.09
13.63
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.00
8.75
11.09
13.63
n
14
14
14
14
14
14
14
16
15
15
15
15
B.
12
13
13
13
14
13
13
15
15
15
14
14
Mean
(I'g/m3)
A.
0.67
2.26
5.48
9.11
11.50
13.6
0.81
1.97
5.14
8.83
11.25
13.70
Z Ace.
ALL DATA
-5.1
-4.2
-3.3
-2.8
-3.0
-l.l
10.0
2.2
1.4
1.7
0.3
-0.9
STATISTICAL OUTLIERS
0.77
2.33
5.53
9.22
11.50
13.76
0.74
1.87
5.14
8.83
11.13
13.90
-2.6
-3.4
-3.0
-2.0
-3.0
-0.8
10.0
2.2
1.4
1.7
0.0
0.1
z cv
28.8
13.7
5.3
7.1
6.1
7.4
42.0
22.3
5.8
5.8
6.0
7.7
REMOVED
15.6
7.3
4.0
5.6
6.1
6.0
29.7
11.8
5.8
5.8
4.8
5.2
n
16
16
17
17
17
17
16
16
17
17
17
17
15
15
16
16
16
16
12
14
16
17
17
17
Cadlum Reduction (12)
Mean
(Mg/m3)
0.86
2.48
5.69
9.24
11.55
13.85
0.65
2.00
5.06
8.68
11.33
13.50
0.81
2.43
5.62
9.42
11.63
13.75
0.62
1.83
5.00
8.69
11.13
13.56
Z Ace.
0.0
0.0
-1.6
-1.9
2.1
-1.9
3.3
1.7
-1.6
-0.6
0.5
-2.4
-1.3
-0.4
-1.7
-1.7
-1.9
-1.9
3.3
0.6
-1.8
-0.6
0.5
-2.4
z cv
30.2
12.1
7.0
9.8
4.6
5.1
20.0
25.0
6.1
5.5
3.4
3.6
21.0
0.1
5.2
6.1
3.8
4.3
16.1
10.4
4.6
5.5
3.4
3.6
-------
TABLE 17. PERCENTAGE OF NITRATE MEASUREMENTS WITHIN INDICATED PER-
CENTAGE OF ASSIGNED VALUE
Audit
0283
0883
Level
1
2
3
4
5
6
1
2
3
4
5
6
Assigned
value (yg/B3)
A.
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.06
8.75
11.12
13.63
10Z
ALL DATA
39.2
66.7
70.6
74.5
76.5
74.5
35.4
60.4
75.0
79.2
83.3
77.1
B. STATISTICAL OUTLIERS
0283
0883
1
2
3
4
5
6
1
2
3
4
5
6
0.78
2.37
5.69
9.48
11.83
14.00
0.60
1.81
5.06
8.75
11.12
13.63
46.5
79.0
81.8
86.4
88.6
88.4
40.5
69.0
85.7
90.5
95.2
88.1
20%
60.7
74.5
84.3
82.4
84.3
82.4
56.3
68.8
85.4
87.5
89.6
89.6
REMOVED
72.0
88.3
95.6
95.5
97.7
95.3
64.3
78.6
97.6
100.0
100.0
97.6
30%
70.6
78.4
86.2
88.2
90.2
84.3
62.5
81.3
89.6
91.7
93.8
93.8
81.3
90.7
95.6
97.7
100.0
97.6
71.4
90.5
100.0
100.0
100.0
100.0
50%
74.5
86.3
92.2
94.1
92.2
90.2
72.9
81.3
91.7
91.7
93.8
93.8
86.0
95.0
100.0
100.0
100.0
100.0
81.0
90.5
100.0
100.0
100.0
100.0
30
-------
TABLE 18. AUDIT RESULTS FOR LEAD ON FILTER STRIPS
Audit
0183
0783
0183
0783
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
n
95
95
97
97
97
97
92
92
91
91
89
92
B.
93
92
93
96
94
95
90
90
89
89
88
89
Assigned
value (pg/m3)
A. ALL DATA
0.58
1.53
2.91
4.13
5.80
7.51
0.75
1.62
2.67
4.18
6.99
8.01
STATISTICAL OUTLIERS
0.58
1.53
2.91
4.13
5.80
7.51
0.75
1.62
2.67
4.18
6.99
8.01
Mean
(yg/n3)
0.58
1.51
2.87
3.97
5.80
7.53
0.74
1.57
2.59
4.05
6.71
7.73
REMOVED
0.58
1.52
2.87
4.02
5.78
7.52
0.74
1.57
2.60
4.06
6.76
7.72
Z Ace.
1.7
-0.7
-1.4
-2.2
0.7
0.7
-2.6
-3.7
-2.6
-2.4
-3.6
-3.2
1.7
-0.7
-1.4
-2.4
0.5
0.7
-2.6
-3.7
-2.6
-2.4
-3.4
-3.2
2 CV
8,6
7.9
7.3
12.6
7.4
5.6
16,0
7.6
5.4
6.4
8.0
4.5
8.6
5 = 9
4.5
7,2
5.2
4.7
8.1
3.8
3.8
4.2
4.3
3.9
31
-------
TABLE 19. PERCENTAGE OF LEAD MEASUREMENTS WITHIN INDICATED PER
CENTAGE OF ASSIGNED VALUE
Audit
Level
Assigned
value (ug/a^)
10Z
20%
30Z
50*
A. ALL DATA
0183
0783
0183
0783
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
0.58
1.53
2.91
4.13
5.80
7.51
0.75
1.62
2.67
4.18
6.99
8.01
B. STATISTICAL
0.58
1.53
2.91
4.13
5.80
7.51
0.75
1.62
2.67
4.18
6.99
8.01
74.0
85.0
89.0
89.0
88.0
93.0
83.7
96.7
94.6
92.4
92.4
89.1
OUTLIERS
76.2
87.6
91.8
91.7
90.7
95.9
83.7
95.7
94.6
92.4
92.4
89.1
88.0
91.0
93.0
92.0
44.0
95.0
92.4
97.8
97.8
97.8
95.7
100.0
REMOVED
90.7
93.8
95.9
94.8
96.6
97.9
92.4
97.8
97.8
97.8
95.7
100.0
94.0
93.0
96.0
96.0
97.0
97.0
95.7
97.8
97.8
97.8
95.7
100.0
95.9
95.9
97.9
97.9
99.0
100.0
95.7
97.8
97.8
97.8
95.7
100.0
96.0
97.0
99.0
98.0
99.0
99.0
98.9
98.9
98.9
98.9
95.7
100.0
96.6
97.9
100.0
99.0
100.0
100.0
98.9
98.9
98.9
98.9
95.7
100.0
32
-------
TABLE 20. AUDIT RESULTS FOR SULFUR DIOXIDE CONTINUOUS MONITORS (ALL DATA)
Flow
setting
1
2
3
4
5
6
Number of
reported
values*
19
172
187
187
187
180
Range of
values (ppm)
0.632 to 0.864
0.403 to 0.626
0.208 to 0.326
0.166 to 0.253
0.040 to 0.091
0.000
Mean differences
ppm
0.005
-0.006
-0.001
-0.002
-0.001
0.001
Z dlff.
0.690
-1.188
-0.584
-0.830
-1.039
Standard
deviation
(ppm)
0.076
0.045
0.024
0.018
0.007
*1983 Audit: Data returned for 187 monitors
33
-------
TABLE 21. AUDIT RESULTS FOR SULFUR DIOXIDE CONTINUOUS MONITORS
BY VARIOUS INSTRUMENTAL METHODS
Flame photometric
Flow average difference
setting n ppm X
Fluorescent
average difference
n ppm Z
Coulometric
average difference
n ppm X
1
2
3
4
5
6
0
-1.1
21 -0.007
22 -0.000 -0.1
22 -0.002 -1.0
22 -0.003 -5.0
20 0.002
152
18 0.006 0.8
143 -0.005 -1.1
157 -0.001 -0.6
157 -0.001 -0.7
157 -0.000 -0.4
0.001
6
6
6
6
6
-0.009
-0.001
-0.003
-0.001
0.000
-2.3
-0.8
-1.7
-2.5
34
-------
TABLE 22. AUDIT RESULTS FOR HIGH-VOLUME FLOW RATE
Results within indicated
No. of I of assigned value
Method results 20Z 40X 601 80%"
Rotameter (visifloat) 13131 1.13 2.38 3.81 5.97
Pressure transducer (continuous) 24672 1.07 2.29 3.69 5.71
Flow controller 1363 1.10 2.30 3.91 5.28
Pressure transducer/flow controller 1401* 1.20 2.23 3.49 5.29
All methods 48445 1.12 2.33 3.77 5.80
*1395 measurements reported
22583 measurements reported
3 136 measurements reported
** 142 measurements reported
55079 measurements reported
35
-------
TABLE 23. ACID RAIN RESULTS FOR pH, CONDUCTIVITY AND ACIDITY (APRIL 1983)
Audit Sample
0483 pH 1
2
3
Conductivity 1
2
3
Acidity 1
2
3
Assigned
value (og/1)
A. ALL DATA
4.51
3.51
3.92
17.10
156.00
65.50
35.40
322.40
127.00
B. STATISTICAL OUTLIERS
0483 pH 1
2
3
Conductivity 1
2
3
Acidity 1
2
3
4.51
3.51
3.92
17.10
156.00
65.50
35.40
322.40
127.00
n
26
26
26
25
25
25
16
16
16
Mean
(mg/1)
4.27
3.39
3.77
35.14
151.41
62.87
44.36
313.05
124.89
'I Ace.
-2.00
-1.14
-0.89
5.26
0.77
-0.61
23.59
6.27
4.29
Z CV
9.54
9.11
9.18
241.89
21.16
21.19
58.46
46.73
51.10
REMOVED
25
25
25
24
24
24
16
16
16
4.33
3.45
3.83
18.15
157.50
65.39
44.36
313.05
124.89
-2.00
-1.14
-0.76
5.26
0.86
-0.46
23.59
6.27
4.29
6.49
3.31
4.59
14.93
6.51
6.86
58.46
46.73
51.10
36
-------
TABLE 24. ACID RAIN AUDIT RESULTS FOR ANIONS (APRIL 1983)
Audit Sample
0483 804 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
Assigned
value (mg/1)
A. ALL DATA
0.600
4.270
2.110
0.140
2.110
0.840
0.400
2.820
1.150
0.050
0.490
0.200
B. STATISTICAL OUTLIERS
0483 504 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
0.600
4.270
2.110
0.140
2.110
0.840
0.400
2.820
1.150
0.050
0.490
0.200
n
24
24
24
25
25
25
23
24
24
17
19
19
Mean
(mg/1)
0.599
4.595
2.202
0.150
2.280
0.918
0.376
2.772
1.095
0.055
0.504
0.207
Z Ace.
0.00
0.94
-1.90
0.00
1.90
4.76
-5.00
1.06
-6.52
0.00
2.04
-5.00
Z CV
40.97
32.42
40.60
26.80
19.82
22.40
14.25
17.27
23.86
33.30
15.66
20.82
REMOVED
22
23
23
24
24
24
23
23
22
16
18
18
0.585
4.294
2.024
0.140
2.203
0.879
0.376
2.849
1.095
0.052
0.490
0.198
0.00
0.47
-2.37
0.00
1.66
4.17
-5.00
1.42
-6.52
0.00
0.00
-5.00
17.14
8.38
9.74
13.60
11.07
7.22
14.25
10.47
12.36
28.25
8.81
9.19
37
-------
TABLE 25. ACID RAIN AUDIT RESULTS FOR CATIONS (APRIL 1983)
Audit Sample
0483 NILj, (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
Assigned
value (og/1)
A. ALL DATA
0.110
0.860
0.320
0.060
0.400
0.150
0.080
0.800
0.550
0.020
0.080
0.060
0.250
1.830
1.360
B. STATISTICAL OUTLIERS
0483 NH4 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
0.110
0.860
0.320
0.060
0.400
0.150
0.080
0.800
0.550
0.020
0.080
0.060
0.250
1.830
1.360
n
19
20
20
19
20
20
21
22
22
19
20
20
22
22
22
Mean
(mg/1)
0.117
0.932
0.387
0.084
0.404
0.166
0.083
0.822
0.541
0.019
0.079
0.062
0.254
1.782
1.240
Z Ace.
0.00
0.58
6.25
16.67
5.00
0.00
0.00
0.00
-4.54
0.00
0.00
0.00
-2.00
0.00
-5.51
Z CV
22.33
24.23
59.81
43.24
19.30
40.70
44.47
10.40
11.19
49.43
14.41
14.57
23.91
21.00
21.01
REMOVED
18
19
19
18
19
19
20
21
21
17
19
19
21
21
21
0.114
0.889
0.339
0.078
0.418
0.154
0.079
0.812
0.532
0.016
0.081
0.061
0.242
1.859
1.293
0.00
0.00
6.25
16.67
5.00
0.00
0.00
0.00
-5.46
0.00
0.00
0.00
-4.00
0.55
-4. 41
19.32
13.63
26.36
30.73
11.58
24.17
40.64
9.06
8.75
36.81
11.56
10.78
8.73
6.05
5.77
38
-------
TABLE 26. ACID RAIN AUDIT RESULTS FOR TRACE METALS (APRIL 1983)
Audit
0483 Mn
Fe
Cd
Cu
Ni
Pb
Zn
0483 Mn
Fe
Cd
Cu
NI
Pb
Zn
Assigned
Sample value (mg/1)
4
5
4
5
4
5
4
5
4
5
4
5
4
5
B.
4
5
4
5
4
5
4
5
4
5
4
5
4
5
A. ALL DATA
0.120
0.030
0.090
0.030
0.140
0.020
0.210
0.060
0.130
0.060
0.400
0.120
0.870
0.160
STATISTICAL OUTLIERS
0.120
0.030
0.090
0.030
0.140
0.020
0.210
0.060
0.130
0.060
0.400
0.120
0.870
0.160
n
15
16
15
14
14
14
16
16
15
15
13
13
14
15
Mean
(mg/1)
0.125
0.037
0.092
0.033
0.144
0.025
0.334
0.058
0.132
0.052
0.401
0.113
0.803
0.161
Z Ace.
0.00
0.00
0.00
0.00
3.57
0.00
2.38
0.00
-7.69
-16.67
0.00
0.00
-2.30
0.00
Z CV
9.99
41.88
14.93
36.66
21.62
48.99
138.92
21.04
30.06
14.90
7.59
15.05
26.59
7.61
REMOVED
14
15
15
13
12
13
15
15
14
14
12
12
13
14
0.122
0.034
0.092
0.031
0.143
0.022
0.218
0.055
0.122
0.054
0.408
0.117
0.858
0.159
0.00
0.00
0.00
0.00
3.57
0.00
0.00
0.00
-7.69
-16.67
1.25
0.00
-2.30
0.00
6.56
21.67
14.93
31.01
7.49
32.50
11.66
9.33
9.18
9.28
3.44
5.29
7.14
5.99
39
-------
TABLE 27. ACID RAIN RESULTS FOR pH, CONDUCTIVITY AND ACIDITY (NOVEMBER 1983)
Assigned
Audit Sample value (ag/1)
1183 pH 1
2
3
Conductivity 1
2
3
Acidity 1
2
3
B.
1183 pH 1
2
3
Conductivity 1
2
3
Acidity 1
2
3
A. ALL DATA
4.45
3.72
3.49
19.00
135.00
165.80
35.80
202.50
339.40
STATISTICAL OUTLIERS
4.45
3.72
3.49
19.00
135.00
165.80
35.80
202.50
339.40
n
29
28
30
26
25
27
14
15
15
Mean
(mg/1)
4.42
3.69
3.45
18.00
125.59
152.52
52.71
233.24
371.07
% Ace.
0.00
-0.40
-0.29
-5.79
-3.11
-4.22
22.91
9.14
4.27
2 CV
2.97
2.13
2.74
27.46
19.90
19.91
53.10
22.64
13.64
REMOVED
27
27
29
24
24
26
13
14
15
4.44
3.69
3.46
18.07
130.24
157.73
45.85
221.69
371.07
0.45
-0.27
-0.29
-5.79
-2.96
-4.07
17.32
8.40
4.27
2.34
1.92
1.98
13.88
7.18
8.87
25.18
13.13
13.64
-------
TABLE 28. ACID RAIN RESULTS FOR ANIONS (NOVEMBER 1983)
Audit Sample
1183 SO^ (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
Assigned
value (mg/1)
A. ALL DATA
0.570
3.720
5.920
0.030
1.380
1.020
1.010
10.330
4.170
0.050
0.130
0.200
B. STATISTICAL OUTLIERS
1183 504 (reported 1
as S) 2
3
N03 (reported 1
as N) 2
3
Cl 1
2
3
F 1
2
3
0.570
3.720
5.920
0.030
1.380
1.020
1.010
10.330
4.170
0.050
0.130
0.200
n
26
26
28
24
24
26
26
25
27
17
16
18
Mean
(mg/D
0.616
3.932
5.971
0.045
1.360
1.006
0.996
9.772
4.165
0.054
0.132
0.213
Z Ace.
0.00
-0.13
-1.10
0.00
-1.09
-1.96
-1.48
-2.23
-3.12
0.00
-3.85
5.00
% CV
42.49
43.74
42.27
107.68
5.67
6.80
31.52
19.98
12.30
41.35
25.48
11.49
REMOVED
25
25
27
22
23
25
25
24
25
16
15
17
0.570
3.621
5.570
0.031
1.352
0.999
0.956
10.067
4.046
0.051
0.125
0.209
0.00
-0.54
-1.35
0.00
-1.45
-1.96
-1.98
-2.23
-4.08
0.00
-7.69
5.00
19.79
18.82
25.01
28.08
4.97
5.98
25.40
13.01
7.24
34.94
14.73
8.78
41
-------
TABLE 29. ACID RAIN AUDIT RESULTS FOR CATIONS (NOVEMBER 1983)
Audit Sample
1183 NH^ (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
Assigned
value (ng/1)
A. ALL DATA
0.330
1.790
0.340
0.110
3.630
2.060
0.050
1.470
2.680
0.010
0.370
0.250
0.080
1.440
0.260
B. STATISTICAL OUTLIERS
1183 NH4 (reported 1
as N) 2
3
Ca 1
2
3
K 1
2
3
Mg 1
2
3
Na 1
2
3
0.330
1.790
0.340
0.110
3.630
2.060
0.050
1.470
2.680
0.010
0.370
0.250
0.080
1.440
0.260
n
21
20
22
24
23
25
25
24
26
23
23
25
25
24
26
Mean
(mg/1)
0.334
1.724
0.371
0.193
3.251
1.892
0.084
1.525
2.744
0.021
0.379
0.257
0.094
1.536
0.368
Z Ace.
0.00
-2.51
0.00
0.00
-9.09
-8.74
0.00
3.74
3.17
0.00
2.70
4.00
-12.50
4.17
3.85
2 CV
15.02
13.72
37.03
125.76
10.41
9.78
151.64
10.78
7.79
135.23
7.65
6.50
98.93
8.92
118.35
REMOVED
19
18
21
22
21
24
23
23
24
22
23
25
24
23
25
0.320
1.722
0.344
0.125
3.254
1.864
0.048
1.550
2.745
0.017
0.379
0.257
0.077
1.520
0.284
-3.03
-2.51
0.00
0.00
-9.09
-8.73
0.00
4.08
3.17
0.00
2.70
4.00
-12.50
4.17
3.85
8.00
7.30
17.02
63.65
6.18
6.67
51.20
7.40
5.33
116.61
7.65
6.50
49.95
7.59
24.56
-------
TABLE 30. ACID RAIN AUDIT RESULTS FOR TRACE METALS (NOVEMBER 1983)
Audit
1183 Mn
Fe
Cd
Cu
Ni
Pb
Zn
Sample
4
5
4
5
4
5
4
5
4
5
4
5
4
5
Assigned
value (mg/1)
A. ALL DATA
0.020
0.040
0.020
0.070
0.020
0.060
0.020
0.460
0.230
0.020
0.680
0.420
0.050
0.480
B. STATISTICAL OUTLIERS
1183 Mn
Fe
Cd
Cu
Ni
Pb
Zn
4
5
4
5
4
5
4
5
4
5
4
5
4
5
0.020
0.040
0.020
0.070
0.020
0.060
0.020
0.460
0.230
0.020
0.680
0.420
0.050
0.480
n
14
15
13
15
15
16
16
16
13
12
16
15
14
14
Mean
(mg/D
0.041
0.065
0.026
0.077
0.028
0.064
0.024
0.442
0.248
0.026
0.539
0.381
0.052
0.476
Z Ace.
0.00
25.00
0.00
14.29
0.00
0.00
0.00
-1.09
8.70
50.00
-9.56
-7.14
10.00
0.00
I CV
183.66
101.72
70.74
35.74
111.48
16.01
95.86
22.08
8.51
25.88
35.37
18.24
21.51
5.58
REMOVED
13
14
12
14
14
15
15
15
13
11
15
14
13
14
0.021
0.048
0.022
0.072
0.020
0.062
0.019
0.464
0.248
0.027
0.571
0.395
0.055
0.476
0.00
25.00
0.00
7.14
0.00
0.00
0.00
0.00
8.70
50.00
-8.82
-5.95
20.00
0.00
23.76
20.37
43.27
27.28
19.61
6.68
56.79
9.17
8.51
17.13
25.66
10.96
12.09
5.56
43
-------
AVERAGE ACCURACY, ptrcant
k rs» O Kl
c
-^
rt>
CO
O
CO
CT
CT
CT
ro
-i
O)
Q.
O)
o
o
c
o
-c
-------
11/76 04/77 10/77 04/78 10/78 04/79 10/79 04/80 10/80 04/81 10/81 04/82 10/82 04/83 10/83
AUDIT DATE.month/vetr
Figure 2. SC>2 bubbler audits precision.
45
-------
12/76 06/77 12/77 06/78 12/78 06/79 12/79 06/80 12/80 06/81 12/81 06/82 12/82 06/83 12/83
AUDIT DATE, month/ywr
Figure 3. NC>2 bubbler audits accuracy.
-------
60
40
30
ts
<
oc
£20
12/76 06/77 12/77 06/78 12/78 06/79 12/79 06/80 12/80 06/81 12/81 06/82 12/82 06/83 12/83
AUDIT DATE, month/year
Figure 4. NO2 bubbler audits precision.
47
-------
10/76 03/77 09/77 03/78 09/78 03/79 09/79 03/80 09/80 03/81 09/81 03/82 09/82 05/83 10/83
AUDIT DATE, month/yur
Figure 5. Carbon monoxide audits accuracy.
48
-------
so
40
§ 30
C9
<
ee
1 I T
10/76 03/77 09/77 03/78 09/78 03/79 09/79 03/80 09/80 03/81 09/81 03/82 09/82 05/83 10/83
AUDIT DATE, month/yur
Figure 6. Carbon monoxide audits precision.
49
-------
10/76 02/77 08/77 02/78 08/78 02/79 08/79 02/80 08/80 02/81 08/81 02/82 08/82 02/83 08/83
AUDIT DATE. month/yMr
Figure 7. Sulfate audits accuracy.
50
-------
10/76 02/77 08/77 02/78 08/78 02/79 08/79 02/80 08/80 02/81 08/81 t)2/82 08/82 02/83 08/83
AUDIT DATE, month/yur
Figure 8. Sulfate audits precision.
51
-------
10/76 02/77 08/77 02/78 08/78 02/79 08/79 02/80 08/80 02/81 08/81 02/82 08/82 02/83 08/83
AUDIT DATE. monht/y«ir
Figure 9. Nitrate audits accuracy.
52
-------
10/76 02/77 08/77 02/78 08/78 02/79 08/79 02/80 08/80 02/81 08/81 02/82 08/82 82/83 08/83
AUDIT DATE, month/year
Figure 10. Nitrate audits precision.
53
-------
10
I
6
I I I I I
-10
08/77 01/78 06/78 01/79 07/79 01/80 07/80 01/81 07/81 01/82 07/82 01/83 07/83
AUDIT DATE,month/VHr
Figure 11. Lead audits accuracy.
54
-------
so
40
30
ta
cc
£20
10
01/78 07/78 01/78 07/78 01/80 07/80 01/81 07/81 01/82 07/82 01/83 07/83
AUDIT DATE, month/year
Figure 12. Lead audits precision.
55
U.S GOVERNMENT PRINTING OFFICE 1984-559-111/10716
------- |