10 JANUARY 1972
PROCEEDINGS
ENVIRONMENTAL QUALITY SENSOR WORKSHOP
Novenber 30 - December 2, 1971
Western Environmental Research Laboratory
Las Vegas, Nevada
ENVIRONMENTAL PROTECTION ACENCY
OFFICE OF MONITORING
401 M Street, S.W.
Washington, B.C.
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10 January 1972
PROCEEDINGS
ENVIRONMENTAL QUALITY SENSOR WO JKSHOP
November 30 - December ', , 19 71
Western Environmer.tal Research La >oratory
Las Vegas, Nevada
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF MONITORING
401 M Street, S.W.
Washing4 on, ~.C.
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^REWORD
The problems arising from man's interaction with the environment
are real and, in some instances, serious. Basic to the study of
these problems (how they arose, how they can be solved, how they
can be prevented) if; the province of environmental monitoring and
analysis. An important aid in these investigations is the province
of remote and in si AI sensors utilized in environmental monitoring.
In order to bring together those individuals within the Environmental
Protection Agency (EPA) that are directly concerned with the monitoring
and analysis activities, an Environmental Quality Sensor Workshop was
held at the Western Environmental Research Laboratory, Las Vegas,
Nevada, November 30 through December 2, 1971• The Workshop was
corvened in order to acquaint those in EPA responsible for monitorirg
em/ironmental quality with the latest techniques for sensing environ-
mental pollutants. In addition, there was an attempt to understand
the requirements for sensor systems in each region and to discuss
possible applications of the appropriate sensor technology. In
order to achieve the desired communications and response from the
participants, the attendance was limited to EPA personnel from
Headquarters, the Regions, Centers, and Laboratory and those
Federal Agencies with interests in environmental monitoring.
A roster of attendance is included in this report.
The Workshop consisted of a number of invited tutorial papers
which included all pollution c ategories and panel discussions
devoted to sensor techniques, sensor platforms, data management
and sensor priorities. Complete texts of the tutorial papers
and summaries of the panel discussions are included and constitutes
the major portion of this document.
Following the Workshop a series of recommendations and action items
were prepared by the Monitoring Techniques Division based on discussions
and suggestions resulting from the Workshop. All of the recommendations
support the basic theme of the Workshop: To determine the applicability
of remote and automated in situ sensing within the Environmental
Protection Agency.
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The program and agenda were } repared by a Sti ering Committee
consisting oi' sensor experts -;ithin the agent y. These include:
J. Koutsandreas - Steering Committee Chai -man, ORM
S. Verner - Vice Chairman, ORM
R. Holmes - Executive Secretary, ORM
D. Ballinger - NERC, Cincinnati, Ohio
L. Dunn - WERL, Las Vegas, Nevada
A. Ellison - MERC, Raleigh, North Carolina
M. Felsher - Office of Enforcement
D. Krawczyk - NERC, Corvallis, Oregon
L. Swaby - ORM
C. Weber - NERC, Cincinnati, Ohio
The proceedings are arranged in two basic divisions: Part I
includes the preliminary report of the Workshop, Recommendations
and Actions and the Agenda; Part II presents the general pro-
ceedings; and the Appendices include a WERL news release, a list
of attendees and a glossary oC abbreviated terras.
10 January 1972
Donald C. Holmes
Director
Monitoring Techniques Division
111
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TABLE OF CONTENTS
Part I •- Workshop Summary
Preliminary Report I - I
Recommendations and Actions 1-8
Agenda 1-12
Part II - Workshop Proceedings
Workshop Theme - Willis B. Foster II - 1
Opening Remarks - Donald C. Holme:; II - 5
Tutorial Papers
"Importance of Air Quality Measurement to
Criteria, Standards, and Implenentation
Plans"
D. S. Barth II - 8
"Optical Methods for Detection of
Water Pollution"
S. Q. Duntley II - 15
"Remote Sensing of Environmental Quality
in Relation to Land Management"
L. ¥. Bowden II - 25
Program Papers
"Analytical Problems in Air Pollution Control"
A. P. Altshuller II - 36
"State of the Art in Noise Monitoring"
E. Cuadra 11-79
"Approaches to Water Quality Monitoring"
W. T. Sayers II - 110
"In Situ and Remote Sensing for Solid Wastes"
H. Stierli II - 126
"Radioactivity Sensing - A Current Review"
V. E. Andrews II - 138
"Data Management for Monitoring Pesticides
and Related Compounds"
G. B. Wiersma and H. Tai II - 147
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Workshop Panels
Workshop Discussion. Topics II - 161
Workshop Summaries
Sensor Monitoring Z'echnicjues Workshop
Panel A - Contra :t Sen;.or Techniques II - 164
Panel B - Non-Co itact Censor Technique^ II - 167
Sensor Platforms Workshop
Panel A - Marine and Terrestrial II - 1?0
Panel B - Aircraft and Spacecraft II - 1?1
Sensor Data Management Workshop
Panel A - Current Data Systems II - 174
Panel B - Future Data Systems II - 179
Sensor Priorities Workshop
Panel A - Short Term (1-5 Years) II - 184
Panel B - Long Torm (5-15 Years) II - 188
Closing Remarks
Dr. Delbert S. Earth II - 190
Mr'. John McBride II - 192
Appendices
WERL News Release A - 1
Roster of Participants B - 1
Glossary of Terms C - 1
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?\RT I
A. Preliminary Repori
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PAET I
A. Preliminary Report
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ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
December 7, 1971
MEMORANDUM
"~C: Assistant Administrator for Research and Monitoring
THROUGH: Doputy Assistant Administrator tos Monitoring
SUBJECT: Preliminary Report of the Environmental Quality Sensors
Workshop
The first annual environmental quality sensors workshop was convened
for the purpose oi acquainting those in the Agency responsible for
monitoring environmental quality with some of the latest state-of-
the art techniques for sensing pollutants. Mr. Willis B. Foster
expressed the foregoing purpose and established the workshop theme
by calling for a reliable, efficient and tinely monitoring program
based on the most advanced concepts in sensor technology. Such a
program, implemented on an EPA-wide basis for the total environment,
will enable the Agency to meet the challenge of creating and maintain-
ing a healthful environment. This is in accord with the primary
mission of EPA to set environmental pollution standards, to regulate,
and to enforce.
The workshop was organized ^o that the participants were given
presentations in terms of EIA's responsibility for the total environ-
ment. Every opportunity to mute organizational biases was taken,
and, although each tutorial speaker addressed a particular area, the
workshop is believed to have been reasonably successful in inducing
the participants co perform the necessary integration so that sensor
system requirements were considered from a total environmental point
of view. Participation of some 55 individuals included representatives
from each NERC, WERL, nine legional offices (Region III was not
represented so we plan to take a summary workshop to them), and ten
other federal agencies.
Dr. Delbert Bart* established an extremely important tone for the
meeting in the iritial tutorial paper on monitoring needs and systems
to meet those needs for air pollution. He also emphasized in his
closing remarks, that to fu fill the EPA purposes set by President
Nixon when he created the Agency, the essential requirement is to
develop a coordinated environmental monitoring system. A continuation
of his closing remarks follows:
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...We are never going to get there until we find out where
we are now. We have to determine our starting point. That means
we have to get to knov one another, the people who have been in
air and know the air program have to find out about the water
program and the water people have to find out, about the air and
all the other things, solid wastes, radiation, pesticides. A
meeting like this goes a long way towards getting at least a
start in that direction. I hope that starts that have been made
here will be built on in the future, and in lact we will be able to
develop a coordinated and integrated monitoring program. In so
far as the NERC at the Research Triangle Park is concerned, I assure
all of you in the various Regions that we will do our very best to
help you in any way that we can through the provision of technical
advice, consultation, technical services, ami in general to do our
very best to help you in our areas of expert se. In my own judgement
I think the biggest ne3d we have in this program is the old problem
of developing the environmental monitoring system into an integrated
one. We can not continue to proliferate mori; and more measurements
for more and more detailed pollutants at more and more stations through-
out the entire U.S. We have got to do a better job at developing
more efficient systems. To do this we need indices of total environ-
mental pollution. We need to develop monitoring systems where we
can get the data we need for air, water, solid waste, radiation,
pesticides and noise in some kind of an efficient pattern, and not
with a continued proliferation of more and more stations and more
and more locations to sample for individual pollutants. That would
be a never ending process which becomes extremely expensive. Certainly
in a time when we do not have enough funds, it has to be one of the
directions in which we must move. The second thing I think we need,
and perhaps the most important, is better predictive models. The
better our models are the fewer number of points we have to sample
at in order to determine what the environmental quality is. So
these are the two big things that I see that are needed in this
entire area..."
Jack McBride closed for WERL as follows:
"...From reports ;iven to me I was told that in several of the
meetings the lack of funds or requirements for more funds came up.
I would like to leave /ou with a slightly controversial note and
say that maybe this is a blessing in disguise for all of us. Because
in one way it makes us look to each other to see how we can get the
help that Dr. Barth and Mr. Holmes were talking about. It makes us
look to other agencies and within the organizational structure of
EPA to see how we can ^et help. I think that once we get ourselves
coordinated then we can take better advantage of the funds that are
given us..."
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Finally, the closing comments from John Hagan, speaking for Region
IV, Carl Walter from Rogion VI and Robert Bowden from Region V
seem fairly representative of the total regional viewpoint of this
workshop, and follow
"...I must admit I am going away much more optimistic than
1 was at the opening. The conference has somewhat changed in the
way it has developed. It is not the same kind of a conference
today that it was Tuesday morning. We started out with Regional
people who are involved in day-to-day activities trying to get
something accomplashed at a work-a-day level. We started out also
at the other end of the spectrum with people from headquarters and
from the Office oj Rest arch and Monitoring who had technical
capabilities which are beyond most of the understanding or capability
in the Regions; and I think in the three days that we have been
together we have begun to communicate with each other and come to
understand each others problems. We are no longer talking about
remote sensing. I think that as of this afternoon we have been
talking about an environmental surveillance and monitoring program,
not specifically a remote sensing program. I believe this is progi .^ss
in the right direction. My central theme, which I've repeated often
is that at the Regional level we are involved in implementing present
technology, but present technology is much more sophisticated than
most of us have implemented. I know about the great advances in
satellite communications. That is the only place that I know that
the EPA uses satellites. That is present technology and it should
be implemented at the regional level. The use of sensors, the
technology transfer f i om the point of the instrument development
to the point of testiig and field application I think should be
given much more empha.' is at the regional level. I think we have
opened some lines >f i ommunication here to get that flow of information
going and cooperation started. From that standpoint I think the
Conference has bee i a preat success. Personally, to me, it has been
a great success in getting to know many of you individually that I
haven't met before, and also finding out some of the things that
are going to affect u£ in the regional surveillance operation. Water,
traditionally, has hac regional surveillance and monitoring programs.
Almost a!3 of the other programs represented here today and represented
within EPA, have done their monitoring and surveillance at least in
large regional east aid west laboratory types of setting or on a
national scale. If El A is going to functionalize its organization
at the regional le/el I think some of the centralized programs are
going to have to bo d< central ized. On the other hand, if the monitor-
ing program is eve1.' gc ing to amount to anything, other than the shotgun
approaches of goin;; ort and bringing in anything that is standing still,
we have to have some Headquarters' direction and establishment of
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priorities. In terms of trying to organize EPA into a functional
organization the progrims can learn from one another from past
experience, and I hope that this forum has served to point that
out. As I say, I came pessimistic and go back quite excited about
che possibility of doi ig aerial scanning for preliminary investigation
type of work. I go ba :k anxious to implement a noise program for
evaluating environmentil impact for a proposed new airport in the
Atlanta metropolitan at-ea. I go back with high hopes that the
Regions will develop t.ie capability to respond to air pollution
episodes, such as we had in Birmingham, and at the same time depend
to a large extent on tie capabilities that are being developed at
the National Research Centers to back us up with the research and
technology required.
Only one other th
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better communication down to the regional level to let us know what
is being developed and how we can use either their techniques or
their resources ard to help us implement another program. I think
it hns been pointed out quite1 emphatically that we are short of man-
;,.. A^er, wo are short o resources and therefore we are often forced
to go bat-k to the hard way of. doing it, the manual way of doing it,
rather than drawing upon advanced technology..."
Carl Walter, Region V :
"...I would like to make only two comments. In our Region we
have only four states, but we have two states that are now actively
interested in remote tensing and one of them is pretty far down the
line. In their OJfice ol Geological Survey, that's Iowa's Geological
Survey, they acquired iome multi-spectral photographic equipment
plus some image enhanc ;ment equipment. They have this capability,
they have hired some p-ople that are knowledgeable in remote sensing
and they have organize.1 in the state to ihe point where the Geological
Survey ir Iowa represents 22 other state agencies. It is going to
be a fino focal point ror the usage of remote sensing in the state.
Now there may be other states that are in this same situation, where
they are actually awar>' of these techniques. I suggest this is an
area where we can have some very fruitful cooperation. The second
thing that I woulc liko to say is that when we go out to collect
data that we must cone3rn ourselves only with what data is actually
needed, and will he analyzed and used..."
A few other points need to be made concerning tho Workshop. It
appeared that the participants did recognize the potential value
of long-term reserrch, even though emphasis was placed primarily
on current technology. Even here, however, the regions appear
hampered because they lon't always know what is better or what a
new and advanced nonit>>ring system will do for them. They'are
constrained because of limitations on people and funds from being
as innovative as they .ire capable.
Wide knowledge of inter- and intragency existing capabilities, and
procedures for drawing upon them, are woefully woak. It is an area
needing early attention and support as part of our monitoring
program aimed at the total environment. The individuals are believed
receptive to this.
From the Headquarters' view, if we expect to der:.ve the full
potential from application of remote or in situ .sensors on suitable
platforms, we wil] hav ; to exert a strong push. At the same time
requisite ground truth and data management and interpretation need
complementary effort, as does standardization of methods and equipment,
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As Dr.. Bartii note 1, we need morv predictive modelling to reduce
the number oL" samiling points. Wo also need emphasis on sampling
techniques and mo licoring site location, since deficiencies in
these areas often are attributes v;o u.nalycical measurement short-
comings .
A follow-on industrial conference needs to be planned so that
we can translate some of the sensor/platfoitn requirements to industry
at large. This would allow further elucidation of what industry now
has on the shelf. A useful result of such a conference would be a
comprehensive compendium of sensors, appropriate platforms, and
details of how to use, what limitations to expect, costs, and things
of this nature. As a first step, the survey, "Instruments for
Environmental Monitoring," being completed by the Lawrence Berkeley
Laboratory, under National Science Foundation (Research Applied to
National Needs (RANN)) auspices, should be available in January 1972
for distribution.
As part of the foregoing, and before planning another workshop, we
need to plan and develop a draining course for the regional Surveillance
and Analysis members. Preferably, it should be taken to them as part
of our responsibilities for coordination and planning for Agency
monitoring.
In considering EPA interaction with other Federal agencies, many
opportunities are immediately brought to mind. The National Bureau
of Standards efforts in analytical and reference methods is perhaps
paramount, and we should place a significant amount of additional
support in this effort with them.
The National Science Foundation, through its program of RANN has
a sizable budget and an interest in supporting appropriate work
based on EPA recommendations. OR&M is the focal point for this
program, and a memorandum of understanding is being drafted with
NSF to delineate operating procedures.
The National Photographic Interpretation Center is a unique organi-
zation, and one with which ^PA should be involved in developing
certain sensor data interpretation techniques and a training effort
for selected regional personnel.
The Office of Civil Defense made a brief presentation which high-
lighted a number of capabilities which EPA may wish to utilize.
Among them are its instrument repair and calibration activity existing
in each state; the Civil Air Patrol fleet of some 6000 aircraft, 18,000
pilots, and 30,000 cadets; the annual survey of shelters which might
be capable of adding sociological sampling of interest to air and noise;
the rather extensive trainiig program; and the extensive hard-line
communication system.
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My closing note concei ns the rather notable advances we seem to
have made in this worS shop toward implement i .if; a functional approach
to tie EPA monitoring off or. In in is onu rogard, I believe the
.vorkshop more thjn p^ a for the time, effort, and funds involved.
Donald C. Holmes
Director
Monitori;ig Tecnniques Division
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PART I
B. Recommendations and Actions
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RECOMMENDATIONS AND ACTIONS
^-.e following are recomrnenda'-ions and proposed actions which
were generated by the Sensor Workshop. Some are a direct
result of the panel sessions., while others were suggested by
the Steering Committee members and the General Chairman.
Generally, these recommendations are based upon the following
major premise: Th^re is an immediate requirement for utili-
zation of remote and automated in situ sensors for monitoring
environmental quality.
1. Recommendation: Determine the monitoring plan and
programs for each Region.
Action; The Monitoring Techniques Division will assist
the Surveillance and Analysis Divisions in developing
specific monitoring plans for each Region. These plans
will at least consider the following: Resources necessary;
sensors and platforms to be utilized; priority assignments
and an inventory of problem areas in each Region.
2. Recommendation: Establish a comprehensive sensor data
management facility with the capability of supporting
monitoring activities in the Regions.
Action; The Monitoring Techniques Division in coordination
with the Monitoring Analysis Divisioa will undertake
appropriate action to identify WERL as the EPA location
for the acquisition and processing of remote sensor data.
3« Recommendation; Establish standards for instruments which
acquire data by remote and automated in situ sensors so as
to ensure quality and compatibility with existing EPA data
systems.
Action; The Standard Methods Branch in conjunction with
the Sensors Branch of the Monitoring Techniques Division
will help identify ar d prepare requirements for remote
and automated in situ sensor data acquisition, transmittal
and processing techniques.
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4. Ri-comriio.idatlo i: Establish a standard]-/.ed storage and retrieval
t3/i;tem oapabl-'1 of accopl ing data from all. elements of EPA and
format oomput ..ble with systems currently in use at other
Federal Agenc .es, e.g. AASA, NOAA and U3GS.
Action; The Monitoring Analysis Division will examine the
existing storage and retrieval systems and will inventory
their capabilities and limitations. The review will include:
the sensor data needs of EPA; an identification of existing
data storage and retrieval facilities, a recommendation for
the design of approaches which would utilize existing
environmental systems and data to meet the Nation's
environmental needs.
5. Recommendation; Inform the Regions, Laboratories, and Head-
quarter;; Offices of sensor activities in other Federal Agencies
which relate to environmental monitorin *.
Action; The Monitoring Techniques Division, Sensors Branch,
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will periodically furnish information on the types of sensors
being used and the amounts of sensor data available.
6. Recommendation; Prepare a compendium of information on the
sensors which were discussed during the Workshop.
Action; The Sensors and Standard Methods Branches of the
Monitoring Techniques Division will compile and distribute
the compendium.
7. Recommendation; Inform industry representatives of the
appropriate aspects of the Sensor Workshop.
Action; Tire Monitoring Techniques Division, Sensors
Branch, will contact GPO to determine the requirements for
reprinting and selling the proceedings of the Sensor
Workshop to industry. The Advanced Techniques Branch will
plan and prepare a follow-up briefing for representatives
of interested industrial firms.
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8. Recomrnendation; I lentify the PETS experiment proposals which
are of particular Interest to the Regions.
Action: The Monitoring Techniques Di\d_sion, Sensors Branch,
i,/ill prepare a recommended program of ERTS experiments which
would involve EPA scientists and engineers from each Region.
9, Recommendation; Design a standard format for EPA's remote
platform monitoring mission requirements.
Action; The Monitoring Techniques Division, Standard
Methods Branch, in cooperation with WERL will establish
a uniform mission request form and disseminate it to the
users.
10. Recommendation; Prepare an informational newsletter which
would focus upon the latest developments in such areas as
environmental sensor technology, new monitoring techniques,
standard methods and recent regional monitoring activities.
Action; The Monitoring Techniques Division will investigate
the requirements for publishing a quarterly newsletter and
for compiling a yearly digest of significant articles on
environmental monitoring.
11. Recommendation; Conduct a one week familiarization course
on environmental sensors for the benefit of the Regional
Surveillance and Analysis and Enforcement Divisions during
CY-1972.
Action; The Monitoring Techniques Division, Sensors Branch,
in conjunction with WERL and the EPA Training Division will
develop a one v/eek Sensor Familiarization Course on remote
and automated in situ sensors which will examine their
capabilities, limitations and implementation potential.
12. Re commendation; Prepare a briefing of the Sensor Workshop
for appropriate individuals in Region III.
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Action: The Monitor:'ng Techniques Division, Sensors
Branch, supported by the necessary elements of EPA
will prepare ana pro ,ent the recommended briefing,
13. Rucommeadatiori: Conduc , an annual sensor workshop, similar
to the first, but with greater emphasis on regional planning
for sensor utilization; and include a review of regional
monitoring activities and priorities.
Action; The Monitoring Techniques livision, Sensors
Branch, will plan a sensor workshop in FY-1972.
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PART I
C. Agenda
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AGENDA
ENVIRONMENTAL QUALITY SENSOR WORKSHOP
WESTERN ENVIRONMENTAL RESEARCH LABORATORY
LAS Y:;GAS, NEVADA
NOVEMBER 30 - DECEMBER 2, 1971
November 30
8:3r' 12:00 PM OPENING PLENARY SESSION
Welcome - Dr. Mel/in Carter, Director
Western Environmental Research Lab
Workshop Theme - Mr. Willis B. Foster
Deputy Assistant Administrator
for Monitoring
Remarks by Workshop Chairman - Mr. Donald C. Holmes
Director
Monitoring Techniques Division
ENVIRONMENTAL TUTORIAL SESSION
9:00 - 10:00 "Monitoring Needs for Air Pollution and Systems
Required to Meet Those Needs"
Dr. Delbert S. Barth, Director
National Environmental Research Center
Research Triaagle Park
Dr. S. David Shearer, Director
Division of Atmospheric Surveillance
National Environmental Research Center
Research Triangle Park
10:00 - 11:00 "Optical Methods for Detection of Water Pollution"
Dr. S. Q. Duntley
Director, Visibility Lab
Scripps Oceanographic Institute
11:00 - 12:00 "Remote Sensing of Environmental Quality in
Relation to Land Management"
Dr. L. W. Bowden
Chairman, Department of Geography
University of California, Riverside
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November 30 (continued)
12:30 - 2:00 PM TOUR OF EPA AIRCRAFT
2:00 - 5:30 PM Sensor Monitoring Techniques Workshop
Plenary Session - Mr. John Koutsandreas
National Science Foundation "RAM" Program, Dr. Paul Crai|
"Analytical Problems in Air Pollution Control"
Dr. P. Altshuller, EPA
"State-of-the-Art in Noise Monitoring"
Mrs. E. Cuadra, EPA
4:00 - 5:30 Concurrent Panels
Panel A - Contact Sensor Techniques Panel
Chairman, D. Krawczyk, EPA
Panel B - Non-Contact Sensor Techniques Panel
Chairman, S. Verner, EPA
December 1
8:30 - 12:00 PM Sensor Platforms Workshop
Plenary Session - Mr. John Koutsandreas, EPA
"Approaches to Water Quality Monitoring"
Mr.. William Sayers, EPA
"In Situ and Remote Sensing for Solid Wastes"
Mr. Harry Stierli, EPA
10:00 - 12:00 Concurrent Panels
Panel A - Marine and Terrestrial Panel
Chairman, Dr. M. Felsher, EPA
Panel B - Aircraft and Spacecraft Panel
Chairman, Mr. L. Dunn, EPA
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December 1 (continued)
1:30 - 5:30 PM Sensor Data Management Workshop
Plenary Session - Mr. John Kouts.mdreas
"Radiation Sens! .g—Current, Review"
Mr. V. Andre-rs, EPA
"Sensor Data Management for Monitoring
Pesticides and Related Compounds"
Dr. G. Wiersrna, EPA
T , H. Tai, FPA
3: CO - 5:30 Concurrent Panels
Panel A - Current Data Systems Panel
Chairman, J. Reagan, EPA
Panel B - Future Data Systems Panel
Chairman, Mr. E. Grenning, EPA
December 2
8:00 - 10:00 AM Survey of Remote Sensor Instrumentation
D. Bundy, EPA - MuIMband Cameras
J. Sherman, NRL - Multispectral Scanners
A. LeFohn, EPA - Spectr'Mnetry
M. Felsher, EPA - Laser Bathymeter
10:00 - 11:00 Summaries from Workshops I, II, & III
Sensor Priorities Workshop
Concurrent Panels
Panel A - Short Term Panel (1-5 yrs)
Chairman, Dr. C. Weber, TCPA
Panel B - Long TV rm Panel 0-15 /rs)
Chairman, Dr. A. Ellison, EP\
1:30 - 2:00 PM Summaries from Workshop IV
2:00 - 3:00 Closing Plenary Session
Mr. Jonald C. Holmes, EPA
3:00 - 3:30 Use of OCD for Environmental Monitoring
R. Sandwina, OCD
3:30 - 4:30 TOUR OF WERL FACILITIES
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PAET II
A. Workshop Theme
B. Openmg Remarks
C. Tutorial Paprrs (3)
D. Program Papers (->)
E. Workshop Discussion Topics
F. Workshop Panel Summaries
G. Closing Remarks
H. Appendices
News Release
Roster of Participants
Glossary of Terms
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A. Workshop Theme
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WORKSHOP THEME
Willis B. Foster
Deputy Assistant Administrator for Monitoring
Office of Research and Monitoring
Environmental Protection Agency
W< i shingt on, D. C.
I would like to add my words of welcome to those of Dr. Mel
Carter in wishing you a fruitful and productive Workshop.
We have organized this meeting to bring together those
responsible for monitoring environmental quality to engage in a
free exchange of ideas and to learn firsthand about the monitoring
activities and requirement of the ten EPA regions. In this way we
hope to gain a better understanding of how sensing technology, both
remote and in situ, may be directed to answering the needs of the
regions, states and municipalities.
For those of us in EPA responsible for monitoring the environment,
a further benefit I see arising from the Workshops to follow over the
next three days and from the tutorial papers we will hear this morning
is an appreciation and awareness of the latest advances in the state-
of-the-art sensors and monitoring technology.
I needn't remind this audience that EPA is basically a regulatory
agency whose primary function is enforcement of environmental quality
standards established by statute. Central to this endeavor is a
monitoring strategy which is timely, informative, accurate and com-
prehensive. There are some within and outside this Agency who
question the efficacy of a separate monitoring activity at the
Headquarters level in EPA. Among the reasons cited in support of
this argument is the lack of reference to monitoring in any of the
environmental acts passed by Congress. Happily, Congress is now
recognizing this deficiency and taking corrective action. For
example, the new Clean Water Standards Act, recently approved in the
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Senate by unanimous vote, for ,he first, time ^establishes a
monitoring function for the Environmental Protoo I Ion Agency
allowing this Agency to directly monitor the out/Tall from industrial
plants and municipalities into our rivers, Ic.kes and coastal regions.
Because of this it is evident that the Administrator will want
monitoring identified at the highest possible headquarters level in
EPA. It was, after all, for this reason that he established my
office by EPA Order 1110.22, dated August 1?, 1971. I am confident
that the Congressional action is not an isolated event; we can look
forward to statutory requirements for monitoring in air and all the
categorical programs as well.
The monitoring requirements placed on EPA imply a highly
sophisticated sensor network extending into all the regions, but
coordinated through a central instrumentality, known as the Office
of Monitoring. Briefly, our role is to give programmatic guidance
for an overall monitoring strategy. What do I mean by programmatic
guidance? Programmatic guidance en bail f- manj things but some of the
more important elements would surely induce one following:
a) To provide effective technical, admi ^.strative and
logistical support to the regional surveillance
and enforcement divisions.
b) To establish guidelines for the establishment of
environmental baselines to identify environmental
quality trends.
c) To establish guidelines for timely incorporation of
newly developed monitc ring technique? and equipment
into regional monitoring networks.
d) To establish guideline s for Identification of
short-term and long—^erm monitoring requirements.
e) To provide specialized laboratory and field support
as required.
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f) To establish standards for methods and instrument
performance for regional applications.
g) To assure utilization of state-of-the-art sensors,
techniques, procedures and rr.ethoas.
h) To operate a data transmission network linking
automated in situ and remote sensors with regional
and national data centers.
All these functions, and there are many others, spell out the
role of the Office of Monitoring and its relationship with other
units in EPA, particularly the regions.
However, all the activities I have enumerated rest on the
premise of a vigorous and competent sensor technology program.
In fact, I would venture to s iy that only through a reliable,
efficient and timely monitoring program based on the most advanced
concepts in sensor technology will the EPA be able to meet the
challenge of creating and maintaining a healthful environment
for present and future generations.
Historically, the routine monitori.-g of environmental
pollutants has involved analysis of selected samples collected
"in the field." Such sampling techniques are not only time consuming,
but more important, they have "very limited utility considering the
vast geographic areas and pollution sources that must be monitored
for truly effective environmental monitoring. Clearly, the routine
sampling of environmental quality can only be effectively conducted
through automated In situ or remote sensing instruments which
function in the real-time mooe.
Needless to say, an operational network of in situ and remote
sensing instruments, to be widely deployed a-id effective, must
consist of elements which are relatively inexpensive, reliable,
sensitive, accurate, pollutanb-specific and easily maintained and
calibrated. Instruments which satisfy all these criteria simply
do not exist for many environmental pollutants. A major contribution
of these Workshops will be to pinpoint where further instrument
development is required.
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Ultimately, the acceptance of advanced monitoring systems such
as we will be discussing rests on the intrinsic performance of
the sensors and ins liniments an! the degree to which they satisfy
the aforementioned requirements. Although many advancements in
sensor technology have occurred in recent years, the ideal remote
or automated sensor has yet to emerge, and future sensor development
will be of great conce-n to us. This is particularly so in areas of
electro-optical instrumentation involving correlation or matched
filter techniques and derivative spectrometry, and the new class
of electro-chemical probes using ion selective electrodes where
truly revolutionary developments are occurring in sensor technology.
Looking to the future, it is essential that the evolution of
sensors be closely followed and strongly supported by EPA because
even newer generations of sensing instruments will almost certainly
radically affect techniques for monitoring environmental quality.
We have assembled here at these Workshops the leading exponents
and proponents and possibly opponents <">f environmental sensor tech-
nology to discuss problems which are fundamental to an effective
monitoring program. I am confident that ^he results of these
meetings will constitute an important contribution to EPA's future
monitoring strategy.
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PART II
B. Opening Remarks
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OPENING REMARKS
Donald C. Holmes
Director, Monitoring Technicu.es Division
Office of ?,-jscorch and Monitoring
Environmental Protection Agency
Washington, D. C.
Thank you, Will, for having set the theme for this Workshop.
As General Chairman, I hope with everyone's cooperation and active
participation to bring reality to some of those points in the next
few days. The primary purpose of this first EPA Sensor Workshop
is to review the present state of the art of remote and in situ
sensors. In the process we may determine which sensor techniques
are likely prospects for utilization within the ten EPA regions
in performance of their responsibilities.
Monitoring the environment is a key to effective management
for environmental Quality. It is nearly impossible to detect
environmental changes, desirable or undesirable, natural or man-
made, without established base lines and repeated observations.
Measurements are essential for the identification of environmental
needs and the establishment of program priorities, as well as for
the evaluation of program effectiveness, and they provide an early
warning system for environmental problems whi-Ch allows corrective
action to be taken.
The choice of appropriate environmental monitoring systems
presents some problems themselves: coverage of systems, both
geographically and as to poll itants or parameters, measured, must
be adequate: sensors should be optimally located: measurement
instruments have to be accurate and calibrated to ensure compatibility
of data from one location to another. All of these essential features
must support the need to collect and analyze environmental data on a
near real-time basis.
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Without all of these capabilities, we c -^t accurately
determine our severest problem or a cost-effective method of attacking
it. Nor can we evaluate the success of our efforts. Monitoring is
not a substitute for action, but acoion without the knowledge
provided by adequate monitoring is more likely to be ineffective.
In order to holp achieve the purpose of this Workshop, it has
been organized so that the participants will be given presentations
in terms of the Agency'? responsibility for the total environment.
Though the txitorial speakers will address a particular area, it is
incumbent upon the participants to perform the necossary integration
so we consider the sensor systems requirement from a total environmental
point of view. We have purposely limited the number of participants
to encourage participation. We do have excellent participation from
our ten Regional Administrators and from the three NERC's. It is
my pleasure to welcome the representatives from the other Federal
agencies who are working in allied sensor fields and who have come
to discuss their activities with respect to environmental sensors.
We are planning on holding eight paucl sessions, two concurrently
at each of the four workshops. Time does nob permit each of the
panel sessions to oe held sequentially. We lave arranged to assign
participants to the several panels so that associates from the
same organization will attend the concurrent sessions. As a further
aid to communication, I have asked each of toe panel chairmen to
present a 15-minute summary with recommendations and requirements
from their respective panels on the last day of the Workshop. It is
my interest to distribute the tutorial paper.0, written summaries,
overall summation and appropriate recommendc ^ions, in the form of
a Workshop Rorort.
The Workshop Steering Committee has prepared a discussion guide
for each of the panel sessions. ¥e certainly welcome additional
topics from the participants.
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Please note a few changes and additie;. "o the Agenda as published.
Mr. Jim Regan, EPA, will chair panel session A of Workshop III, and
Mr. Ronald Sandwina, representing the Office of Civil Defense, will
present a closing paper, emphasizing potential areas of cooperation
between OCD and EPA. There are two tours of KERL planned, one today
to observe EPA aircraft capabilities, and one at the close of the
Workshop in the early afternoon on Thursday. There will be further
information regarding hese tours later in the program.
For your beriefrl at this Workshop, the Committee has assembled
copies of professional papers presented recently regarding the
sensing of environmental pollutants. These papers should be of
interest and ought to help stimulate the discussions during the
panel sessions. Now I would Like to introduce the first of our
tutorial speakers. Dr. Del Barth is the Director of NERC,
Raleigh, N.C. Dr. Barth will speak to us on "Monitoring Needs
for Air Pollution and Systems Required to Meet Those Needs."
Next we will hear from Dr. S. Q. Duntley, Director, Visibility
LaDoratories, Scripps Institute, San Lux^o, California. Dr. Duntley
will discuss "Optical Methods for Detection of Water Pollution."
Finally this morning we will hear from Dr. Leonard Bowden,
Chairman, Department of Geography, University of California,
Riverside, California.
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C. Tutorial Papers (3)
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IMPORTANCE OF AIR QUALITY MEASu ^"3NT TO CRITERIA,
STANDARDS, AND IMPLEMENTATION PLANS
D. S. Earth
Director
National Environmental Research Center
Research Triangle Park, N. C.
INTRODUCTION
The Clean Air Ac as amended, P.L. 91-604? states that one of
its purposes to "to protect and enhance the quality of the Nation's
air resources so as to promote the public health and welfare and
the productive capacity of its population." It goes on to define
specific authorities granted to the Administrator, Environmental
Prctection Agency (EPA), that he may utilize to achieve the purposes
of the Act. In brief, some of these authorities are:
1. Designation of air quality control regions, issuance of
criteria and control technique documents, and promulgation
of national ambient air quality standards.
2. Promulgation of national standards of performance for new
stationary sources.
3- Promulgation of national emission standards for stationary
sourcer. of hazardous air pollutants.
4. Promulgation of national emission standards for motor vehicles.
5. Regulation of fuels and fuel additives.
6. Issuance of national aircraft emission standards.
7. Setting of aviation fuel standards.*
A brief di:5cussior of each authority ri.ll be given, with emphasis
placed on the importance of measurements uf pollutants to each case.
It is import aut to bear in mind that Federal policy for air pollution
control is basrd on the need to protect the public from the adverse
effects of pollutants en health and welfare and to enhance the quality
of the total environm' ,:t.
This authority is granted to the Administrator, Federal Aviation
Administration, but it must be based on recommendations of the
Administrator, EPA.
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GENERAL DISCUSSION OF AIR QUALITY
To fully define the quality of air with respect to a specified
air pollutant, it IE; first necessary to define the concentration in
ambient air of that pollutant, t/.e length of time air was sampled
xcr that pollutant, and the location(s) to which the observed con-
centrations are applicable. The description of the location must
include height above the ground as well as location on the ground.
Furthermore, the sampling device used and its sampling rate must be
described as well ae the analytical procedure used to quantitate the
pollutant of concern.
The fundamental importance of air quality stems from the fact
that most effects on human health or welfare are related to pollutant
levels at the locations of the receptors. Important exceptions to
this statement are effects such as decreased visibility or altered
weather or climate, for which a direct relationship between effect
and air quality at a single location is clearly not possible. In
these cases, the important parameter is integrated air quality
through an appropriate layer of the atmosphere.
The concentration of a pollutant at a given receptor is a
quantity that usually results from contributions of that pollutant
from many different stationary and mobile sources. Thus to achieve
an air quality standard, it ia necessary to know all the significant
sources of the pollutant that contribute to its concentration at a
given location. From this knowledge it is then possible to derive
a collection of necessary emission standards for the significant
sources that will ensure that the air quality standard will not be
exceeded.
Even though it is easy to state the principles-involved in
proceeding from air quality standards to emission standards, it is
not easy to apply those principles precisely to special cases for
the following reasons:
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1. Not all significant sources may be ia<_utified.
2. Not all sources may be controllable to the same degree.
3. Meteorological parameters play a dominant role which
is not accurately defined.
4- There may be significant non-man-made background sources
of the pollutant which are uncontrollaole.
The point to be made is that it is not possible with our present
state of knowledge of confidently derive a set of emission standards
for a given ALr Quality Control Region which will assure that the air
quality standards will not be exceeded. Thus even after emission
standards have been determined, promulgated, and enforced, it will be
necessary to continue measuring air quality. Another factor not yet
mentioned, which is also difficult to predict precisely, is the future
growth of sources of the pollutant of coneerr.
In general, then, air quality measurements are needed principally
for the following purposes:
1. To relate observed effects on health of welfare to pollutant
concentrations and averagiiig time (sampling times from
which average pollutant concentrati -ns were determined).
2. To determine the control needed to protect the public from
adverse effects on health or welfaro.
3. To determine efficacy of controls ar> they are installed.
4. To determine non-man-made background levels.
With the general discussion of air quality completed, we will
now examine some of the authorities contained in the Clean Air Act,
as amended, in more detail.
CRITERIA AND CONTROL TECHNIQUES DOCUMENTS
The administrator, EPA, is directed by P.L. 91-60/4 to publish
criteria and control technique documents for those air pollutants.
"(A) which in his judgment have an adverse effect on public
health and welfare;" and
"(B) the presence jf which in the ambient air results from
numerous or diverse mobile or stationary sources."
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Air quality criteria for an air pollutant "shall accurately reflect
the latest scientific knowledge useful in indicating the kind and
extent of all identifiable effects on public health or welfare which
may be expected from the presence of such pollutants in the ambient air,
_n vary quantities." Information on control techniques "shall include
data relating to the technology and costs of emission control. Such
information shall include such data as are available on available
technology and alternative methods of prevention and control of air
pollution." The Act states that "effects on welfare include, but are
no', limited to, effects on soils, water, crops, vegetation, man-made
materials, animals, wildlife, weather, visibility, and climate, damage
to and deterioration of property, and hazards to transportation, as
well as effects on economic values and on personal comfort and well-
being. "
For those materials for irhich criteria and control technique
documents are issued the Admiiistrator is directed to prescribe
national primary and secondary ambient air quality standards which
are defined as follows:
1. "National primary ambient air quality standards shall be
ambient air quality standards the attainment and maintenance
of which is the judgment of the Administrator, based on such
criteria and allowing an adequate margin of safety, are
requisite to protect the public health."
2. "National secondary ambient air quality standards shall
specify a level of air quality the attainment and mainten-
ance of which is the judgment of the Administrator, based
on such criteria, is requisite to protect the public welfare
from any known or anticipated adverse effects associated with
the presence of such air pollutant in the ambient air."
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To date criteria and control technique documents have been
issued and National Primary and Secondary Ambient Air Quality
Standards have been proposed for sulfur oxides, particulate matter,
carbon monoxide, photochemical oxidants, hydrocarbons and nitrogen
oxides. Once these standards have been promulgated, which must be
no later than April 30» 1971? the States have 9 months in which to
develop and submit an implementation plan designed to achieve the
air quality standardr within a rather tight time schedule after
approval of their plan—3 years after approval for primary standards
and a "reasonable time" for secondary standards.
What is the role of air quality data in all of this? First, air
quality data were necessary as a basis for criteria documents. Second,
air quality data are necessary in determining the controls needed to
meet the standards. Third, an integral part of the implementation plan
must be an adequate surveillance network to ensure that progress toward
the standards is measured and documented.
It is planned that all surveillance networks, Federal, State, and
local, will report their data in a compatible format so that all data
may be stored in one central computer repc sitory and retrieved as
required. This will ensure that the appropriate control agencies
receive comparable, accurate, and current data. Steps are now being
rapidly taken to achieve this goal. As more and more State and local
surveillance networks become operational, the Federal Government will
reduce its collection of routine enforcement-oriented data. It is
expected that the appropriate State and local agencies will take over
and continue to operate the existing Feder tl National Air Sampling
Network stations at their existing sites to provide continuity of air
quality dat^. at these locations. The Federal Government will increase
its collection of research and baseline-oriented data. Examples of
such activities include systematic identification and quantitation of
n ew pollutants as we1 j. as detailed surveillance on an ad hoc basis
in the vicinity of eelected major point sources in order to validate,
and/or provide new data for improving our existing predictive models.
Several Federal mobile air quality measurement laboratories are planned
for the future to facilitate this type of operation.
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STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES
"The tern 'standard of performance' means a standard for emissions
of air pollutants which reflects the degree of emission limitation
through the application of the best syst-err. of emission reduction
,;hich (taking into account the cost of achieving such reduction)
the Administrator determines las been adequately demonstrated."
On a tight time schedule set forth in the Act, the Administrator
is required to list and then publish standards for cateogries of
new sources that in his judgment "may contribute significantly to
air pollution which causes or contributes to the endangerment of
public health or welfare." The measurement of air quality plays
no role in this authority of ^he Federal Government.
The Act stipulates, however, the the Administrator shall prescribe
regulations that will establish a procedure, similar to that of the
implementation plans for criteria pollutants, under which each Stat^
shall submit the Administrator a plan that establishes emission
standards for any existing source in the same category of sources
for any air pollutant which is a "non-criteria" pollutant and which
has not been listed as a hazardous air pollutant, and to which a
standard of performance would apply if the existing source were a
new source. Thus all of the uses of air quality data cited under
the section of criteria and control technique documents would then
be applicable for the existing source case here.
NATIONAL EMISSION STANDARDS FOR STATIONARY SOURCES OF HAZARDOUS
AIR POLLUTANTS
"The term 'hazardous air pollutant' means an air pollutant to
which no ambient air quality standard is applicable and which in the
judgment of the Administrator may cause, or contribute to, an increase
in mortality or an increase in serious irreversible, or incapacitating
reversible, illness." The Act requires the Administrator, on a tight
time schedule, to publish a list and then, subsequently, to promulgate
national emission standards for those air pollutants deemed hazardous.
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The emission standards will be applicable to ooth new and existing
stationary sources. In general, standards will be set by defining
internally "reference air quality standards" at the property line of
applicable sources and then using dispersion models t-o back-calculate
to thoss allowable emissions that will ensure that the reference air
quality standards will not be exceeded. The calculated allowable
emissions would then serve as a basis for the national emission
standards. Thus air quality data are needed to develop, improve,
and validate prediction modele linking sources to air quality as well
as to verify subsequently that the control installed achieve the
desired results.
NATIONAL EMISSIONS STANDARDS TOR MOTOR VEHICLES AND AIRCRAFT AND
REGULATOR? AUTHORITY FOR FUELS AND FUEL ADDITIVES TO INCLUDE
AVIATION FUELS
For all of these authorities it is envisioned that control needs
will be based on allowable levels of significant pollutants to assure
protection of health and welfare. Thus, as noted in the last section,
air quality data are needed for development, improvement, and validation
of prediction models Uniting sources to air ^ality and for subsequent
verification that the desired results have been achieved.
SUMMARY AND CONCLUSIONS
Air quality measurements are mandatory for the proper application
of many of the authorities contained in the Clean Air Act as amended.
Thus, in order to get the maximum return for Federal, State, and local
resources devoted to air quality measurements, it will be essential in
the future to develop improved measurement techniques; to optimize
monitoring system design; to develop a common system of calibration,
quality assurance, data validation, and reporting; and to strive for
integrated (with a minimum of overlapping) Federal, State, and loca]
air quality surveillance networks. We are currently working hard to
achieve these ultimate "oals.
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OPTICAL METHODS FOR DETECTION OF WATER POLLUTION
S. Q. Duntley
Visib.i lity Laboratory
Scripps Institution of Oceanography
University cf California, San Diego
There is little doubt that standard, analytical, chemical
techniques for water analysis supplemented by laboratory biological
tests provide the most accurate and reliable source of knowledge
concerning pollutants in natural waters, but these techniques are
slow and expensive. They require water samples to be obtained and
returned to a laboratory for for specialized laboratory equipment to
be brought to each water location. Optical techniques are faster
and adaptable for use in the field, but not all kinds of pollutants
can be detected or their concentrations measured by optical means.
In some cases optical detection can be done from aircraft and even
from spacecraft. It is not the purpose of this talk to catalog every
optical technique nor to discuss specific commercially available
devices. Rather, I shall speak about certain principles which
underlie the more promising optical methods.
This audience is doubtless familiar with the available standard
works which describe analytical chemical techniques for water quality
determination. You also know that the research committee of the Water
j'Dilution Control Federation publishes each year a literature review
of new analytical methods. More than 600 papers involving new methods
have appeared in the last three years, and some of them are optical
techniques. Most of the new methods stress speed and state that it is
a critical factor in pollution studies. Many of the new laboratory
methods are no more accurate than older ones but they are faster.
Among the new optical methods are found spectroscopic techniques
for the detection of phenol or petroleum in water. There are spectro-
chemical techniques for copper, lead, zinc, nickel, chromium, aluminum,
iron and manganese as well as for the alkali metals. Aluminum can now
be assayed by fluorometry, a can phosphates. The oxygen content of
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water can be assayed by new chromatographic tec-uiiques as well as by
new ultraviolet absorption methods. There are new fast colorimetric
determinations for chromium, cobalt, and aluminum as well as for
organic acids and for the measurement of ph and alkalinity. Chroma-
tography has also been used for measuring pesticides in water, herbicides
and organic acids as well as petroleum and phenol. Some of the new
techniques involve continuous flow of devices with automatic recording
of the pollutants and thfxr concentrations.
Work has been done on contact sensors that can be anchored or
mounted in bodies of natural water to analyze and record certain
pollutant conditions. If desired, they can transmit their data to
a central station by radio and even be interrogated by a data-collecting
satellite system.
Later in this talk I will return to the topic of optical in situ
monitoring devices and mention rome very new optical approaches. First,
however, let us consider some optical remote sensing techniques for
water pollution. Those concerned with the quality of water in streams
know that a discharge of pollution somewherv along a river often goes
undetected until the material ic many miles d iwnstream and there is no
indication from whence it came. Clearly, patrol of such rivers by
aircraft equipped with proper photographic devices or other optical
remote sensors offers a chance of finding the source of the pollution.
Wherever large area coverage is essential, patrol by aircraft, perhaps
even by spacecraft, may be the most effective procedure.
Airborne techniques have detected and measured pollutants, like
oil, floating on water surfaces. One of the rost graphic and sensitive
methods is by photography or observation in the edge of the glitter
pattern formed by reflection of the sun. Evidences of floating oil can
be detected throughout the gliti er pattern, but this rarely, if ever,
is accomplished in a single phoiograph. This it; because the dynamic
range of photographic film is not sufficient to cope with the enormous
range of glitter patterr brightness. With normal exposures the presence
of floating oil appears as a pattern of dark streaks in the edge of the
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glitter pattern. Actually these are not great masses of oil, but
thin layers floating upon the water surface. Why do thin oil streaks
shor so plainly in the edge of the sun glitter pattern? The reason
goe^ ba^v "oo an old adage of the sea which has t,o do with pouring oil
'-.. jubled waters. Mariners have known for a long time that rescue
rrdssions at sea involving life boats can be aided by pouring oil on the
surface of the water to diminish the water waves. The surface tension
of floating oil is significantly greater than that of a clean water surface.
The interaction of wind with water to produce waves is governed by surface
tension, particularly when the wind speed is low over the water surface.
Whenever the wind blows, tiny wavelets appear due to elastic deformation
of the surface tension layer. These tiny elastic waves involve much
the same physical principles that are involved in the capillary rise
:f liquids in small tubes, and for this reason they are called capillary
uaves. They are quite different in almost every respect from large
water waves in which energy is stored in the form of gravitational
potential energy wherever the water rises and sinks as the waves progress.
These large waves build up over a period of time as the' wind blows and
persist as rollers after the wind has died. Their slopes are small and
their optical effect is minor when photographed from high-flying aircraft.
The tiny capillary wavelets, however, are present almost instantly when
the wind begins and vanish as quickly when it ceases. Their tiny facets
are steep and, since the surface of the water is covered with them, they
control the space-averaged reflectance characteristics of water. Thus,
any floating substance which alters surface tension will alter the
appearance of a windruffled water surface. The way this works is shown
diagrammatically in Figure 1. Here an aerial camera looks vertically
downward on the water surface. This is uniformly covered by capillary
wavelets and illuminated by sunlight. If the fieldof view of the camera
extended far to our right, it would record the center of the sun glitter
pattern. If the water was calm, it would record a reflected image of
the sun. But since the capillary waves are present it sees a large
bright nearly circular pattern, brightest at its center where the solar
reflection point is located. The brightness of the pattern diminishes
rapidly toward all of its edges and the camera looking downward at th
edge of this glitter pattern sees the water surface dark on our left
but light a little further to our right.
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Experiments have shown that, averaged over a ijirge area of water
surface containing thousands of individual wave facets, the fractional
area of water surface tipped in any specified direction follows a nearly
Gaussian distribution, in which flat, horizontal facets are the most
common occurrence. At the solar reflection point, flat, horizontal
facets reflect sunlight directly to the camera and because horizontal
facets are so numerous, the water surface appears dazzlingly bright.
Indeed each tiny horizontal water surface has the reflected brightness
of the sun and may, there 'ore, be more than a million times brighter
than any facet which reflects some other part of the sky. Directly
beneath the camera, however, horizontal water surfaces reflect the
sunlight too far to the left to enter the lens. Only surfaces having
the proper tilt will mirror the sun and appear bright to the camera.
The frequency of occurrence of facets tipped at just the right angle
to fulfill the mirror condition is very much less common than horizontal
surfaces.
The lower curve shows the fractional area of the water wave surface
tipped properly to reflect sunlight to the camera lens. Although only
a few of the tiny capillary wave facets at the • iddle point in Figure 1
fulfill this condition tley are exceedingly bright and cause the average
tone of the water to appear light on the photograph. At the left hand
point, however, almost no facets are tipped sufficiently to fulfill the
mirror condition. Thus, at this point in the picture the water surface
appears dark. The lower urve is a Gaussian distribution having a
variance which is ^report.onal to the speed of the wind over the water
surface. If the wind diminishes, the Gaussian c irve will narrow. Any
increase in surface tension will also make a corresponding narrowing of
the Gaussian peak. That is to eay, if the water surface is covered by
a uniform layer of oil, ths surface will be more calm and the distribution
of slopes will be ;ore narrow. If an oil film lies at the center point
in Figure 1, the w .ter wi-'3 appear more dark to the camera because fewer
facets are suffici -ntly s^ jep to fulfill the mirror relation. Thus,
in the idge of the glitter pattern a water surface having streaks or
patches of floating oil a]pears bright where the water surface is clean
and dark wh^re it : s calmrd by floating oil.
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The sensitivity of this mechanism for the detection of small amounts
of oil on the surface of water is greatest where the Gaussian is steep.
Interpretation is easiest in the extreme edge of the glitter pattern.
If normal photographic exposures are used, there will be a comparatively
sm^lo. region of the photograph where streaks of oil on the surface of
the water show prominently. This region is part of a circular band
centered on the solar reflection point. The footprint of high
sensitivity for detecting floating oil is limited to a rather small
angular field. In the case of low altitude vertical photography, the
amount of water surface it covers is ordinarily too small to be useful,
but in the case of high altitude aerial photography a very practical
area coverage can be obtained.
A complete photographic oil coverage survey of a river, lake, bay,
or harbor can be made as follows:
An aerial camera of moderate size is equipped with panchromatic
film, a red filter and an intervalometer set to take a series of vertical
photographs with a large overlap (e.g., 70 o/o). It is flown over the
water at high altitude on a clear day with the sun high in the sky.
The pilot flies directly away from the sun on a course that carries
the plane over the area of interest. The resulting series of pictures
contain a succession of footprints of high sensitivity which can be
combined in the form of a mosiac showing the distribution of oil floating
over the entire surface of the water.
The sensitivity of the sun glitter method of oil survey may be one
of its weaknesses. Like many other remote sensing techniques it requires
a priori information on an in situ check to make sure that the oil is
indeed of a harmful variety and of significant amount. Other remote
sensing techniques can be employed to help the situation. For example,
it is a fact that oil has a much higher reflectance in terms of ultra
violet light than does a clean surface water. Thus, in ultraviolet
imagery oil slicks appear white. Far infrared imagery also reveals the
presence of oil on water but the interpretation is less simple because,
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depending upon temperature, the oil can appear either darker or lighter
than the surrounding water. Thermal infrared (line-scan) imagery is
best for pinpointing the source of an oil spill; ultraviolet imagery
is best for indicating its extent, and shortwave solar infrared is
useful for distinguishing the oil slicks from floating vegetation.
Aerial imagery of water surfaces that does not shewn the sun glitter
often reveals the presence of sub-surface materials. These may sometimes
be pollutants or they may be indicators of pollution. For example,
chlorophyll-bearing marine plants, usually microscopic in size, bloom
wherever advantageous conditions of nutrients and sunlight occur.
Photosynthesis occurring in these plants uses solar energy to produce
food materials and liberate oxygen. In the dee]) ocean the presence of
these phytoplankton may indicate rich fisheries and this is sometimes
true of inland waters. On the other hand, the growth of green plants
and water may indicate the presence of pollution and they may be
responsible for eutrophication. From the standpoint of the present
optical discussion, however, it is unimportant whether the presence
of chlorophyll-bearing plants in water is j;ood or bad. It is only
important to know how their presence can be detected and reliably
distinguished from quite different materials which may be present in
natural waters.
Those who swim along the surface of water witn a mask and snorkel,
or those who have had the experience of riding in a glass bottom boat,
know that the color of deep water as seen beneath the surface has many
characteristic colors. Very clear water appears a beautiful luminescent
blue, reminiscent of the clear zenith surnme, sky. Mhen clear water
contains an abundance of chlorophyll-bearing phytoplankton it may appear
to be a rich ^reen, while water containing silt may appear like coffee
with cream. In shallow water, the bottom has a profound influence and
the composite color depends not only upon the water and its contents
but also upon the color of the bottom. Figure 2 illustrates two of
these cases. The curve marked 0.1 represents blue-appearing, deep,
clear ocean water containing only a small amount of chlorophyll-bearing
II - 20
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phytoplankton. Vast areas of oceans are typified by water of this
kind. Thare is some organic productivity and some fish are found,
but not elough to make a rich fishery. At some other clear-water
location rfhere upwelling brings nutrients from the depths, there
; „ _, much larger standing crop of microscopic green plants. The
daylight reflection spectrum as seen beneath the water surface is
shown by the other curve on this slide. This depicts rich green water,
having 100 times the chlorophyll concentration of the first curve.
Noncontact detection of chlorophyll by optical means would seem
to be a simple matter on the basis of curves like those in Figure 2,
but the spectrum can be complicated by the presence of silt, bottom
influence, and colored products due to the decaying of plant and
animal life in the water. Nevertheless, chlorophyll-rich water has
certain distinctive spectral features which may enable a sufficiently
definitive analysis to be made from measurements at a few wavelengths.
Note t* at the two curves cross in the green region of the spectrum
where the wavelength is near 520 nm. Curves representing intermediate
concentrations of chlorophyll in clear water all pass, through this same
point. It is as if the curves were all hinged here. This means that
a monochromatic measurement at this wavelength will be independent of
the chlorophyll concentration. Such measurements provide an opportunity
to allow for other water properties, the quantity of available daylight,
sky reflections, atmospheric effects, and so on without regard to the
presence or absence of chlorophyll. At shorter wavelengths, in the
blue region of the spectrum, chlorophyll absorbs sunlight strongly and
converts some of the absorbed energy into chemical potential energy
through photosynthesis. It is this energy that is responsible for the
production of oxygen and food materials. Clearly, increasing concen-
trations of chlorophyll-bearing phytoplankton cause the reflectance of
the ocean to decrease in the bli e region of the spectrum. Thus,
measurements of reflectance in terms of blue light can be compared with
the reflectance of the water at the "hinge" wavelength in the green in
order to determine quantitatively the concentration of chlorophyll in
water, provided no other colored substance is present to confuse the
readings. In the deep oceans this is true more often than in bays,
rivers, or lakes.
II - 21
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In the" yellow-green-1 part-of "the spectrum at, say, 5^0 nm the
presence of phytoplankton causes the reflectance of water to rise.
(See Figure 2.) This is because phytoplankton scatter light of this
wavelength Mt do-not abso'rb it. The interplay between absorption
altd' scattering in s"e"a water1 is a complex subject,, treated ordinarily
by methods of radiative transfer analysis. The equations are well
known but complicated except in clear water cases where, to a useful
engineering approximation, the spectral reflectance of deep water is
linearly proportional to the ratio of the back-scattering coefficient
for downwelling daylight to the total absorption coefficient. Figure 2
demonstrates that the addition of chlorophyll-bearing phytoplankton to
sea water causes absorption dominated optical effects in the blue region
of the spectrum and scattering dominated optical effects in the yellow-
green, with a "hinge" point at 523 nm between. This is a unique set
of spectral properties by means of which chlorophyll-bearing materials
can be sensed in natural waters. A properly chosen three-wavelength
differential spectroradiometric measurement (i.e., one involving ratios
of spectroradiometric measurements at different wavelengths), contact
or non-contact, should enable chlorophyll concc .trations in water to be
distinguished and assayed, even in the presence of most sediments,
organic decomposition products, or industrial wastes.
Perhaps the most common optical technique using contact sensors
for the identification and measurement of dissolved materials is ab-
sorption spectroscopy. Laboratory workers are usually familiar with
techniques which employ small optical devices consisting of a lamp,
a filter, a container for some fluid through wh' ^h the filtered light
passes and a photo-electric cell to measure the amcrint of light trans-
mitted by the fluid. These are usually called abridged spectrophotometers.
There are many makes on the market and a very wide variety of techniques
for their use. All of these techniques are based upon the studies that
have been made in research laboratories equipped with recording spectro-
photometers that draw the complete spectral curve of the materials and
II - 22
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work out the technique s involving filters which isolate points on
these curves. No form of analysis or measurement can be fraught
with more pitfalls than the use of abridged spectrophotometers which
measure at only one or two wavelengths. If these instruments are
y ^ under circumstances in which the shape of the absorption spectrum
is distorted by any unexpected substance or by any physical factor,
such as a change in ph or temperature, drastic errors may be made.
Research spectrophotometers which record spectral curves are expensive,
but their use in the only sure way to avoid pitfalls in dealing with
uncertain situations. Even so, the recognition and positive identifi-
cation of a substance by the shape of its spectrophotometric curve is
not easy when several absorbing substances are present. In such
cases there is a useful but old technique, based upon a very well
known principle that is often overlooked. The method is rigorous
only in clear solutions, where scattering is very small compared with
absorption. That is to say, fluids, which although colored, are clear.
Then the transmittance T of a path of length x is given by the simple
"~i'lCX
exponential expression e ' , where a is the absorption coefficient for
a unit concentration and e is concentration. Spectrophotometers plot
curves of transmittance versus wavelength for absorbing fluids. If a
series of such curves are plotted corresponding with various concentrations,
it will be found that the shapes of the curves are quite different. If
the substance of interest is only one component in a mixture, its recog-
nition may be very difficult. Some spectrophotometers produce curves
in the form represented b;r the equation ln(l/T) = acs. The ordinates
of such curves are seen to be proportional to the triple product acx.
Curve shape again depends upon concentration, and identification of
components is nearly as difficult as before. If, however, spectrophotometric
curves are represented by bhe equation
In ln(l/T) = In a + In c + In x,
the curve shape is determined solely by the absorption coefficient a,
because concentration c ard thickness x do not vary with wavelength.
In this form, components cf mixtures can be identified with much
greater certainty.
i: - 23
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The complexities of organic absorption spectra and the scattering
effects in fluids have posed major difficulties for those engaged in
medical research. The quest for improvements in optical techniques
of this kind will probably never cease, but it appears that an important
breakthrough is occurring at present. I refer to derivative spectroscopy.
That is to say, to analysis techniques based upon curves of the deriva-
tives of the spectrum rather than the spectrum itself. It is often
possible to separate and identify the optical characteristics of particular
materials in the presence of interfering spectral signatures by employing
the second derivative of Ihe spectroradiometric curves. This can be
illustrated in terms of the chlorophyll example used previously in this
paper. Figure 3 shows two overlapped second derivative spectra: One
is derived from the in situ reflectance curve in Figure 2 which relates
to rich chlorophyll-bearing water having a concentration of 10 mg/cubic
meter. For comparison there is reproduced a second derivative spectrum
curve derived from airborne measurements with an airborne spectro—
radiometer flown at an altitude of 2500 feet above a chlorophyll-rich
ocean area by Peter White, of the TRW Corporation. The remarkable
similarity of White's curve in the green, oran^ 3, and red regions
of the spectrum shows that the second derivative optical characteristics
of chlorophyll-bearing phytoplankton are unperturbed by the sky reflection
at the water surface and by atmospheric effects in the lower atmosphere.
From the standpoint of non-contact sensing this is a very exciting result.
The recent scientific literature demonstrates that derivative spectro-
scopy is exciting the life scientists. It may also open important
possibilities for the optical detection and mon- toring of pollution.
II - 24
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CJ
cc.
CJ
CLEAR OCEAN WATER
CONTAINING CHLOROPHYLL A
back-scattering coefficient
WAVELENGTH (NANOMETERS)
II -
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GAMBIA
FRACTIONAL AREA OF
WATER WAVE SURFACE
TIPPED TO REFLECT
SUNLIGHT
TOWARD CAMERA
II - 26
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T
T
T
SECOND DERIVATIVE
SPECTRUM
OF OCEAN WATER
CONTAINING
CHLOROPHYLL
520 530 540 550 560 570 580 590 600 610 620
WAVELENGTH (NANOMETERS)
II - 2?
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REMOTE SENSING OF ENVIRONMENTAL DUALITY IN
RELATION Tt) LAND MANAGEMENT
Leonard "-/. Bowden, Ph.D.
Associate Professor of Geography
University of California, Riverside
Remote sensing of the environment, when properly applied, is a
technique to monitor environmental quality. The phenomena sensed is
that which influences quality and includes numerous things that man
can experience. Many of the phenomena in mans experience are unlikely
to be subject to remote sensing, but they cannot be ignored. In other
words, a system of remotely sensed indices of envlronmcmtal quality
may be developed and used effectively to inform but should not be used
to dominate policy.
In a like manner, we have been negligeni in failing to fully use
remote sensing techniques as a means to aid future land management.
All too often, detection of effluents, evaluation of already blighted
areas or spot checking of conditions is as f.ir as remote sensing gets
used. Unfortunately, newly )ormed politica and popular fronts for the
assessment and improvement of environmental quality run the risk of
using ill-informed and ill-ccnsidered popular action that will allevi-
ate some problems detected by remote sensing and aggravate other, more
se-ious problems.
It seems clear that no policy regarding environmental quality,
whether remote sensing is involved or not, c< uld bo meaningful if it
took less than a regional perspective or out ook and often a world-
wide view is desirable. It also seems clear that when dealing with
land use and/or land management, anything less than predictive models
for future use and preventive models for future quality deterioration
are necessary.
Land does not exi?t in £ny definable "jure" form—geologically
or ecologically — and land pollution means departure from a normal
rather than departure from a pure state. Because the land is both
diverse and subjeez to natural or cultural change, the key problem is
II - 2^
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to determine if the changes are within a broad "normal" range or if
they are degradative. And, can degradation be identified, classified
and judged? Is it harmful to man and nature?
A land environment is always subject to pollution be it volcanic
dust, deer manure or disposed beer cans. Most pollutants are soon
broken down or integrated into the environment through decay, burial,
settlement and so forth. Over the eons, absorption, oxygenation, and
consumption easily clear and disperse small amounts of pollutants.
Interaction in the environment among land, air, water and biomass tends
to stabilize or control excessive pollution. Except in geologic time
spans, little alteration occurs on the natural landscape. However,
man has recently upset the cycles of erosion, deposition, decay and
regrowth by impressing on the total environment a new and demanding
cultural landscape.
Cultural or human pollution of the land has expanded exponentially
in the last two centuries. Streams have become sewers unable to dis-
pose or control the material dumped into them. Rural areas are
collectors of discarded junk and urban Cities are ribbons of refuge
and garbage surrounding dismal housing am uncontrolled development.
At the same time, water and air have also been polluted and ecological
systems disturbed and interrupted. The magnitude and intensity of the
problems have become so much greater in recent years that they have
blossomed into major political issues. The problems have also gener-
ated conflicts penetrating all segments of the economic system.
At the present time, limited government action is the rule to be
followed. Standards arc to be set, actior ordered and so forth by
various local, national or international governmental agencies. There
are very fevj guidelines for either the private citizen or private in-
dustry to follow to be a lesser land polluter. The concept that the
only social responsibility of business is to use resources and engage
in activities designp'1 to increase profits so long as the business
stays within the rules of the game (Friedman, 1962) places the burden
on government to set the rules.
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However, damage to the land arises from so many sources that only
intense cooperation by private and public factions can produce the
slightest positive result. And then the index we use to measure the
results may also be misleading.
The most widely used index is the Gross National Product (GNP)
which represents the goods and services produced in a given period
and moving through market channels. As the name implies, GNP is
"gross" because it disregards the conventional kind of depreciation,
the wearing out of plants and equipment, etc. However, tax deductions
are allowed for depreciation to business for such declines. Yet,
nobody depreciates the land, allows for wear out or pollution in any
form. The GNP does not take account of depreciation of environmental
quality. In fact, increase in GNP is often at the demise of resources.
If pollution, for example, eroded rather than bolstered the GNP,
government agencies and private industry may well have cleaned up the
environment years ago Cans sen, 1970)..-
Unfortunately, so much of our pollution is unmeasurable in money
terms such as effect on GNP. How does one value a beer can on the
landscape when the production and consumptic a of the beer and container
added to the gross national wealth. Somehow a change in indices is
necessary before individuals or agencies can take action to remove or
retard pollution. One may detect a sugar beet field full of salinity,
but to advise the farmer on action or guidelines to remove or reduce
salinity is a different situation, especially if it lowers his annual
income.
In the less clearly defined realm of cu-turally altered landscapes
our mobile population is capable of spoiling one region after another.
Except possibly in Alaska, so little "wilderness" remains that, even
if it all were preserved, it cannot serve a population that seeks it
out as a relief from its culturally blighted landscapes of normal re-
sidence. The potential for degradation of the quality of living is all
around us. First notea in the deteriorating environments of the urban
scene, it is now prevalent in all parts of western societies' landscape
(Aschmann, 1971).
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Within the capability of remote sensing lies three critical and
applicable possibilities as summarized from Aschmann (op. cit.).
1. The. capability to inventory our entire national territory in
terms of environmental characteristics that affect the quality of
human 1iving.
2. Early detection of slight but progressive environmental changes.
3. The identification of patterns and associations of variable
and disparate environmental features, both natural and cultural, that
society can associate with desirable or undesirable environments.
The first of the three above is most critical. The least elastic
of the nations (and the worlds) resources is land and land space.
Space on, above or below the urban concentrations is of greatest value
yet the non-urban space remains critical to our natural resources but
is being progressively pre-empted.
It seems worthwhile to inventory in some detail the spaces in and
around urban population concentrations to determine what fractions re-
main and in what land use. How much of the nation's land is in "single-
purpose pre-emptive land use?" What are the evolving patterns?
Urban and regional planners need to r cognize the ways urbanized
landscapes evolve. They make few land use maps, owing to their cost
by traditional field survey methods, and, as a consequence a map's
utility is limited to a historical or illustrative value and its major
value, when used synoptically to observe economic patterns rearranging
themselves, is lost. The application of remotely sensed data can help
change the situation. Urban fringe problems are widely recognized:
(1) disparate land usage and the gross ineificiency of any distribution
system that services disconnected development whose conversion is not
phased incrementally, (2) from an agricultural investment view, blight-
ed landscapes have social cost in the loss of interim use returns due
to "clouded" planning futures and the disinvestment strategies it
prompts, (3) agricultural produce also incurs a higher transportation
cost. While a policy regulating rural-urban land use conversion in
increments of growth is lacking in the United States, a synoptic method
comparing a series of photographs can point out where land owners may
II - 31
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initiate a conversion long before the necessary formal procedures are
begun. Planners or policy makers may take action when they observe
agricultural patterns entering an urban-trasition process. By remotely
observing tangible land use evidence of decision-making, the synoptic,
photographic interpretation urban growth theory (land economics and
locational theory) greatly facilitate the planning of the urban fringe
(Goehring, 1971).
Evolving land use anu management change ,can be detected early with
the use of synoptic remotely sensed imagery. Goehring (1971) found
evidence that urban land use successions can be predicted several years
ahead of their actual development. Urban and regional planners can
foresee transition problems and where they occur, while they develop.
Whether they can or will do anything about the problems depends on
policy.
Basically, detection of environmental quality should mean early
detection of indices or surrogates so that action can be taken. When
blighted districts are fully developed they are easily identified visu-
ally by almost any observer. We need to recognize earlier the signa-
tures of blight or declining environmental qu lity. We need to recog-
nize those combinations of physical landscape and cultural management
that are associated with and precede blight.
During the 1960's, we established that impoverished rural environ-
ments, urban housing quality, land deterioration and classes of socio-
economic conditions were definable from remote sensing methods. All of
our research efforts, mostly in Chicago, Asheville Basin, and southern
California were checking the system to see if ^e could compete with
ground based observers in doing land use, land and housing quality,
inventory and evaluation of existing land resources. Now it is time
we used our capabilities to project the future of land use and guide
land management in a meaningful way to protect environmental quality.
However, one proceed.'- with the above if he knows, or thinks he
knows, what is a desirable environmental quality. It seems that man
needs, in addition to food, clothing and shelter, numerous other items
to be satisfied. The most important is diversity. A monoculture or
II - 32
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monolandscape seem to be unattractive, whether they are continuous,
similar suburban homes or flat, horizon seeking grain fields. Yet,
there is no extensive documentation on such important indices as (1)
change, (2) boundary, or (3) individualism. Nor is there historical
documentation of the relation of the above three to attitudes or en-
vironmental quality. Mullens, working with imagery of Los Angeles,
found he could class urban housing quality in relation to middle class
income by examining three factors—vegetation, litter and open space.
In a like manner, hazards to living (earthquake, fire, flood,
tidal wave, landslide, etc.) are identifiable in a regional and often
local sense. All of these are predictive, not after the fact. They
are not monitoring of past events that deteriorate man's happiness
but are projections of where the deterioration can come from. Of
course, such items as housing density, industrial location, and rec-
reation area use are well within the realm of being remotely sensed.
In the 1970's, those of us who have looked at remote sensing
applications for a long time, are starting to realize some of the
actual potential. An example might be the aetermination of environ-
mental land quality prior to the invasion of an interstate highway
plus the prediction of what it will do—not just locally but regionally
and nationally. Aschmann states that the concept of the "right and
wrong side of the track" has been with us for a long time. But remote
sensing should be able to furnish us the data to foresee an area that
will become the "wrong side of the track" when and if certain phenomena
occurs.
Of course, information taken from remote y sensed data is only use-
ful as a surrogate of what the real scene is. As is the case where
both privacy and social contacts are sought on alternate basis.
Crowdedness, or the lack of it, of things on the land is most certainly
detectable by remote sensing. What is not distinguishable is the desire
for privacy or social contact. However, as one builds the totality of
environment from those data bits of remote sensing, often a picture or
some insight is formed. Land use, transportation facilities, energy
II - 33
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supplies, recreation opportunities, or more simply "the role of man's
activities on the land" are readily subjected to analysis with remote
sensing methodology.
Occasionally, there are surprises such as finding out that urban
vegetative condition sensed with color infrared photography is directly
correlated with quality of housing and neighborhood income. On the
other hand, some apparent sensors are not as useful as the engineering
might lead you to believe. Thermal infrared scanners at one time seem
to be a potential tool for night-time traffic monitoring but as yet have
failed to make the step.
There has been too much publicity on how remote monitors can detect
crop vigor, thermal outflows, stream effluents, forest fires and others.
It is time we brought the need for land use planning, prediction of land
and environmental quality and the capabilities oi" remote sensing together.
In a nation that has the technology and hardware to sense every acre of
land but no regional, state or national land use policy, the time for
both is overdue.
There is no question that remote seusings greatest contribution is
in the detection and inventory of land use, No other method of survey
or analysis comes near to remote sensing when land use data is desired.
As has been stressed earlier, once the land use is known, then the real
or potential "land pollution" can be described. Just as important is
that land use is a prime key to existing and potential air and water
pollution.
Overall, the "state-of-art" of remote sensing is technically ad-
vanced to the point oi being very useful f> r detection of land pollution.
The major drawback is "what" to detect and "how will it effect policy?"
In effect, before any evaluation as to "benefit-cost" can be made, costs
that have previously been part of the social or cultural pollution of
production must be subtracted. As a result, standard economic series
such as GNP will have a rather bleak look for a long time. If pollution
control efforts should expand significantly, new guidelines will be
needed to interpret what the statistical series are telling us and what
the remotely sensed data are telling us about economy and environment.
II -34
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Once the policy changes are r.iade, the new data will not be comparable
to data in use today. As a result, remote sensing of the environment
will play a much more significant role in eflrly detection of pollutants
and serve as a method of mon tioring policy £nd regulation enforcement.
Aschmann, H. Homer, "Prolegomena to the Remote Sensing of Environmental
Quality", ProCr ssional Geographer, XXIII, 5 January 1971, 59-63.
Bowden, Leonard W., "Sensing Land Pollution", Proceedings, American
Institute of Aeronautics and Astronaut! 's, Palo Alto, California,
October 1971.
Friedman, Milton, Capitalism and Freedom, Chicago: University of Chicago
Press, 1962, 133.
Goehring, Darryl, "Monitoring the Evolving Land Use Patterns on the
Los Angeles Metropolitan Fringe Using Demote Sensing",, Technical
Report T-71-5, Department of Geography, University of California,
Riverside, (in press).
Janssen, Richard F., "Gross National Product", The Wall Street Journal,
October 17, 1970, 1.
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ANALYTICAL PROBLEMS IN AIR POLLUTION CONTROL
A. P. Altshuller
Research and Monitoring Of, ice
Environmental Protection Agi r.cy
National Environmental Research Center
Research Triangle Park, North Carolina
INTRODUCTION
A small program concerned with development CM new or improved
techniques for measuring air pollution has existed for quite some time,
but particularly from the inception of Federal activities in 1955.
Until 1967, this program was primarily concerned with support of
research and monitoring needs.
Between 1955 and 1967, a large number of laboratory analytical
uechniques were developed for air pollutants. Considerable research
was done on development of colorimetric and chromatographic techniques.
These techniques were applied to air quality measurement and to motor
vehicle emissions research. During this period la small number of air
quality instruments, particularly those for oxidants and hydrocarbons,
were evaluated and improved. Most of the colorimetric procedures
used in air quality instruments were developed or improved during
this period.
By the mid 1960's, it was apparent that new techniques and sensors
were becoming available. Gas chromotographic techniques were well
enough developed to jus ify their use in monitoring instrumentation,
but the necessary resources were not available. The costs -involved
in incorporating a laboratory technique into an eifective monitoring
instrument for routine general use are considerable.
The Clean Air Act, as amended in 1967, referred to instrumentation
requirements in two sections. Section 104 states: "The Administrator
may conduct and accelerate R/0 of low cost instrumentation techniques
to facilitate determination oL quantity and quality of air pollution
emissions, including, but not limited to, automotive emissions". In
] - 36
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Section 133» annual reports to Congress are required, including a
report of progress on "The development of quantitative and qualitative
instrumentation to monitor emissions and air quality". These passages
in the Act stimulated for the first time the allocation of resources
for instrumentation R&D. The pace of these activities has accelerated
slowly but significant]/ since the passage of these 196? Amendments.
It was clear by 19^7 that most of the instruments available for
measurement of air quality were deficient in sensitivity, specificity,
or ease of operation and maintenance. Emphasis was placed on the
development of a new generation of instruments using physical principles
rather than wet chemistry. Many of these instruments can be used, with
some modification, for monitoring emissions from motor vehicles and
from stationary sources.
The 1970 Clean Air Act also involves additional measurement capability
for mobile emission sources. The development of new power sources or
propulsion systems requires that we hav^ analytical procedures capable
of qualitatively and quantitatively measuring pollutants "which cause
of contributes, or are likely to cause or contribute to, air pollution
which endangers the public health or welfare but for which standards
have not been prescribed" in accordance with Section 202 of the 1970
Clean Air Act. In general, Section 202 requires that measurement
techniques be prescribed for any air pollutant, for which standards are
promulgated, that is emitted from motor vehicles.
Evaluation of instrumentation for measuring emissions from stationary
sources has recently been initiated in acco: dance with provisions of the
1970 Clean Air Act. Section 110 (2 F), on Implementation Plans, states
that approval of such plans shall include, among other aspects, "require-
ments for installation of equipment by owner or operators of stationary
sources to monitor emissions". Section 144» on inspection, monitoring,
and entry, states: "T] ;- Administrator may require the owner or operator
in carrying out provisions of Section 110, 111, and 303 to (C) install,
use and maintain monitoring equipment or methods; (D) sample such emissions
II - 37
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(in accordance with such methods, of such locations, at such interests,
and in such manner as the Administrator shall prescribe." These provisions
certainly will require the acceleration of both 3&D and the evaluation
and standardization of instrumentation and of sampling and analysis
procedures for emissions from stationary sources.
A list of important a~*eas of need for air pollution measurement
capability are listed in Table 1. The listing is divided among air
quality, motor vehicle emission, and stationary source requirements.
The order within each area proceeds from research on pollutant composition
and concentration, as related to atmospheric characteristics and bio-
logical effects, to regulatory needs. Most of the techniques presently
available resulted from earlier R&D programs of air quality surveillance
activities. However, the Environmentt1 Protection Agency will soon
outrun this reservoir of measurement capability when it begins impending
regulatory programs. It is essential that measuring requirements for
R&D projects be supported now, or the mes, '"ing techniques will not be
available for regulatory requirements later. The complexity of the
process and the timing involved will be considered in greater detail
later in this discussion.
Important criteria for air quality instrumentation are listed in
Table II. Of course, tht-se same criteria apply to many other instruments.
Sensitivity requirements can vary greatly. For monitoring air pollution,
the ability to measure 10 to 1000 up/meter. It appears that at stationary
source applications the concentration range wil1 be 100 to 1000 times
higher. It follows that an instrument may nav more than satisfactory
sensitivity for monitoring stationary source emissions, but totally
inadequate sensitivity for measuring ambient air quality. Response
times of 1 second or less are needed for some motor vehicle applications,
whereas periodic analyses oice every 5 or 10 minutes, or even less
frequently, are required •' >r other air pollution measurements. Fortunately,
it is possible to develop instruments vi-th appropriate characteristics for
the entire range of applications.
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A reasonable position is to develop the minimum set of different
instruments. Such an approach will tend to minimize instrument develop-
ment costs, reduce problems of reliable commercialization of instrumenta-
tion, and speed standardization and collaborative testing programs. This
approach must also produce instruments adequate for each of the applica-
tions listed in Table I -t a reasonable cost per instrument.
A sequence of activities required to develop and commercialize an
instrument is given in Figure I. In many past and some present instrument
projects, a pronounced tendency to bypass a number of steps in the given
process had prevailed. The net result has been either unusable instru-
ments or expenditure of much work in rebuilding instruments. -> Aside
from the cost and inefficiency involved in them, such abbreviated approaches
actually prove more time-consuming than an approach that systematically
follows through on the necessary steps as listed. As indicated in the
time scale, it is most unusual for this sequence to take less than 2
to 24- years; the sequence can require more than 3 years if research
problems occur early in the process or if prototypes must be redesigned.
The substantial period of time indicateu. here as essential for
development of a satisfactory instrument reemphasizes the need to
anticipate instrument requirements very much in advance of regulatory
deadlines. Unless they are developed for R&D projects, prototype
instruments will not be available when required for regulatory standards.
Cumbersome and often inadequate manual analytical methods must be
substituted, to the discomfort of all, while +he overdue instrumentation
is being developed.
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AIR QUALITY MEASUREMENTS
Instrumentation for Measuring Atmospheric Gases and Vapors
This discussion will be concerned primarily with the present
status of and anticipated needs for instruments that can monitor ambient
air. Point sampling instrumentation, along with remote and long-path-
type instrumentation, v: il be considered for the monitoring of gases.
Ambient air monitoring needs will be considered to include not only
determination of urban pollution, but measurement of pollution on a
regional and global scale. Because a number of atmospheric substances
of concern are not primary emissions from chemical reactions, atmospheric
transformations must be considered.
Methods of analysis and instrumentation available up to about 1966
have received detailed consideration in a number of reviews (l-?).
Therefore, this presentation will emphasize advances in the last
several years. Our first concern is with the justification for the
development of new or improved instrument., tion. It will be
necessary to consider the deficiencies of irstruments that
have been available until recently to analyse ambient air.
Almost all of the air-monitoring instruments installed up to 1970
were based on analytical approaches developed 10 to 15 years earlier.
Many of the individual types of instruments are cumbersome, of low
specificity, of limited sensitivity, and difficult to maintain because
of complexities of design. Some of the instruments suffer from only
one or two deficiencies, while othurs fail r almost all aspects. As
a result, the amount of valid measurement dt.oa obtained has frequently
been limited.
Attempts wet 3 made to improve some of these instruments with
respect to specifxcity of response for ozone (8) and hydrocarbons (9,10).
Such activities were vie-'sd as temporary expedients necessary because
of the lack of funds tc develop new instruments. The approach usually
taken was to utilize a substrate in the iiilet system of the instrument
II - 40
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which would remove or hold back interfering substances. Experience
has shown that such systems do not work very effectively in routine
monitoring operations, although they can be handled successfully by
R&D personnel in field studies. No R&D activity can anticipate all
of the problems associated with operations under a variety of routine
conditions in the field. Variability in time to partial or complete
breakthrough of the interferences through the substrate under varying
atmospheric conditions is one of the problems often experienced. In
general, instruments that require use of auxiliary clean-up systems
to achieve specificity are more prone to give incorrect results than
instruments whose basic sensing principles confer the required
specificity.
A number of instruments have been in common use in monitoring
networks during the past 10 to 15 years. When these instruments are
considered in terms of sensitivity, specificity of response, simplicity
of response, simplicity of construction c^d operation, or reliability
and reproducibility of operation, they have proved inadequate, usually
with respect to several of these criteria, ^s a result, few concerned
persons have expressed satisfaction with instruments available during
the last 10 or 15 years in monitoring networks. Unfortunately, little
incentive and fewer resources were available to remedy the situation
until recently.
Although the resources available in the last several years have
been modest, considerable progress has been made, particularly with
respect to new or improved instruments for measuring inorganic gases.
Instruments ha~"e been developed which are now receiving or have received
field evaluation for sulfur oxides, ozone, carbon monoxide, nitric
oxide, and nitrogen dioxide. In addition, a better technique for
determination of non-methane hydrocarbon has been developed. Most
of these instrument deve 'opments have utilized sensors or laboratory
equipment produced by research in recent years. However, a considerable
range of activities has been required to convert these into usable air
11-10.
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pollution monitoring instruments. Sensora had to be evaluated with
respect to sensitivity and specificity for urban air pollution require-
ments. Long-term stability and reproducibility or operation had to
be evaluated. Breadboard laboratory equipment had to be packaged as
field instruments. Field studies have been required to permit comparisons
of instruments used for °ach of the several pollutants under representative
ambient air conditions. Such investigations, from laboratory evaluation
of the potential for applicability of a sensor to air pollution needs
through field evaluation, require several years of continuing efforts.
Field evaluations indicate that all of these instruments have the
sensitivity and specificity needed for urban air pollution applications.
The instruments also should be capable for measuring so-called near-
urban pollution.
The gas chromatographic technique for carbon monoxide and methane
utilized in former year^ in laboratory photochemical studies (11-13)
was developed into a convenient monitoring instrument (14» 15)- In
combination with a capability for measuring total hydrocarbons, such a
gas chromatographic analyzer provides a high _y specific and sensitive
means of analyzing carbon monoxide and non-methane hydrocarbons over
a wide range of atmospheric concentrations. As a carbon monoxide
analyzer, the gas chromatograph is much more sensitive and specific
than current non-dispersive carbon monoxide analyzers. This approach
can also be extended to include monitoring for other gaseous hydrocarbons.
The direct analysis for methane is much more desirable than the earlier
attempt to use substrates to remove hydrocar> ons other than methane
(9» 100. This type of technique has given erratic results in routine
monitoring activities because of the care necessary to maintain the
characteristics of the substrate utilized to provide the specificity
required* Another technique developed for methane and other hydro-
carbons involves select" re combustion, with subsequent detection by a
water sorption rensor (16).
11-42
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The present oxidan I, analyzers are unsatisfactory monitoring tools.
The "oxidant" has no exict meaning since the response obtained depends
on the presence of various interfering substances. The substrate used
to eliminate sulfur dioxide interference oxidizes nitric oxide to
nitrogen dioxide and thus increases the signal caused by nitrogen
dioxide (8). Recently, it has been shown that hydrogen peroxide is
an atmospheric oxidant, but the response of commercial analyzers to
this oxidant is poor (!'/)• It should be evident that each of the
major oxidants should be measured separately. Several ozone analyzers
have been developed and evaluated under field conditions. All of these
instruments are based on utilization of chemiluminescent reactions (18).
The three types of reactions involved are as follows: (l) reaction of
ozone with Rhodamine B Absorbed on silica-gel disc (Regener Method),
with emission at 0.59 micron; (2) mixing of ozone with excess nitric
oxide, resulting in chemiluminescence from excited nitrogen dioxide
that extends from 0.6 tc 3.0 microns; and (3) mixing of ozone with
excess ethylene, resulting in a chemiluminescence peak near 0.43 micron
(Nederbragt's Method). All of these systems xrovide a specific and
sensitive means of analyzing ozone rapidly over an adequate linear
range. However, both the Regener (19, 20, 21) and the ozone-nitric
oxide techniques (18, 22) have several disadvantages, compared to the
Nederbragt technique, for use in a routine air monitoring instrument
(18, 23, 24).
The Regener approach requires preparation and calibration of the
disc. Because of the activation and decay chcracteristics of the
chemiluminescent surface of the disc, a 4-minute mode of operation is
preferable; the mode involves a calibration cycle, purge cycle, sample
sycle, and purge cycle (20, 21). This type of operation also complicates
methods for obtaining signal read-out. The ozone-nitric oxide reaction
requires use of reduced j^essure to avoid quenching the chemiluminescent
reaction (18, 22). Detection of emissions in the spectral region
involved dictates the use of photomultipliers near the edge of the
II - 43
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chemiluminescent response above 0.6 microns; thus cooling to -20 C is
required to obtain a sensitivity down to 0.01 ppra. The Nederbragt-
type detector can operate at atmospheric pressure -without quenching
and with a sensitivity down to 0.003 PPm at 5 C with a less expensive
photomultiplier (l8, 23, 24). The ozone-ethylene reaction can be
used with a detector of less complicated design, excellent operation,
and the good cost and size characteristics.
The flame photometric detector has received considerable attention
in our program for measurement of sulfur dioxide, hydrogen sulfide,
and other sulfur compounds (14, 25, 26). This technique involves a
response to both inorganic and organic sulfur compounds because these
substances form S_ species in the flame zone which are responsible for
the emission observed. Several field evaluation studies already completed
have demonstrated the effectiveness of this sensor, both as a sulfur
analyzer and as a detector in a monitoring gas chromatograph (26). This
approach is more attractive than most of the other techniques available
for measuring sulfur compounds. The flame photometric sensor has the
following characteristics: (l) high specificity for sulfur compounds
if emission is measured between 0.39 and 0.40 micron; (2) high sensitivity
(0.005 ppm) ; (3) linear response in ambient air concentration range;
(4) fast response characteristics; (5) and a gas flow system (no liquid
reagents). The flame photometric sulfur detector is also the only
detector sensitive to sulfur compounds that can be used practicably
in a gas chromato graphic analyzer. When sulfur dioxide is the pre-
dominant sulfur species present, the flame -photometric analyzer can be
used as essentially a sulfur dioxide monitor. The gas chromatographic
analyzer has Deen used as a specific and sensitive measuring instrument
for sulfur dioxide, hydrogen sulfude, and methy mercaptan (26). The
gas chromatographic system has been readily modified to measure a
wider variety of organ:1' ". sulfur compounds where appropriate, such as
in the vicinity of kraft paper mills (2?).
II - 44
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Several varieties )f electrochemical or electroanalytical
techniques have been utilized in sulfur oxide monitors (28). Research
and development continujs on these approaches. Electroanalytical
techniques are rarely specific. Liquid or solid substrates are often
used to confer specificity. One type of electrochemical transducer
utilizes a selective membrane along with a galvanic cell having an
electrode potential sel3cted to reduce interferences. Work has been
done on selection of el3Ctrode and electrolyte materials and membranes
for development of sulf ir dioxide and mitrogen oxide analyzers (29).
This sulfur dioxide analyzer is a compact, relatively low-cost instrument.
Its sensitivity at present is adequate for short-term emission measure-
ments but is marginal for continuous measurement of sulfur dioxide.
The sensor utilizes l.)N H SO, electrolyte, a gold sensing electrode
and a lead dioxide counter-electrode with a 1-mil polyethylene membrane.
With potentiometric control, interference from nitric oxide is low,
but hydrogen sulfide constitutes a significant interference. Response
time is less than a minute. This analyzer ^ equires improvement for
use in ambient air analysis. Because of its lode of operation,
simplicity of construction, compactness, and low cost, it offers
possibilities for use in large monitoring networks for measurements
averaged over extended time intervals, such as 24-hour periods.
Measurement of nitric oxide in the ambient atmosphere has involved
use of analyzers utilizing the colorimetric Griess-Ilosvay reaction for
nitrogen dioxide (9)> ifi which the nitric oxide is oxidized to nitrogen
dioxide before analysis. A number of efforts mve been made to over-
come difficulties in developing an oxidizing substrate capable of
providing high xw/ersicn efficiencies over a range of atmospheric
conditions. The stoichiometry of the colorimetric nitrogen dioxide
reaction used has been in dispute (30). In addition, the nitric oxide
and nitrogen dioxide colorimetric analyzers have been difficult to keep
in proper operation. Nc electroanalytical or ultraviolet analyzer has
yet been provided that is adequate for ambient air monitoring of nitrogen
oxides. The need for irrproved instrumentation is particularly urgent
for nitrogen dioxide.
II - 45
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At present the most promising approach involves the use of
chemJluminescent emissions from the lectronic transition, NCu - NCU,
produced in the reaction of nitric oxide with ozone (22). The emission
spectrum extends from 0.6 to 3 microns, with maximum intensity near
1.2 microns. This method for nitric oxide by determination is linear
from 0.004 ppm up to 10,000 ppm. Photomultipliers responding from the
outset of emission at 0.6 micron to their cutoffs at 0.8 to 0.9 micron
have been evaluated. To obtain a sensitivity down to 0.004 ppm, choice
of photomultipliers must be optimized and the operating temperature of
the photomultiplier reduced to -20 C. Since such sensitivity is not
needed in measurement of source emissions, less sensitive photomultipliers
operating at room temperature can be used. For a wide range of gases
present in polluted air, quen< hing of the cher.iiluminescent reaction has
not been > 'bserved at reduced pressures. No interfering species have
been identified. This same reaction has been mentioned earlier as one
met nod foi ozone measurement.
The reaction of nitric oxide with atomic oxygen produces excited
staies that emit weakly, with some line structure occurring between
0.35 and (.45 micron, followed by a more intense unstructured band
with a minimum near 0.65 micron (32). Since atomic oxygen reacts with
nitrogen dioxide to form nitroc oxide on a one-to-one basis, this
reaction can be used to measure NO + N0?. This reaction can be used
as the basis of a rapid-response instrument for measuring nitrogen
oxides. Use of the emission in the 0.65 micron region only provides
discrimination against the chemiluminescent enissions produced by
the corresponding reactions of atomic oxygen vith carbon monoxide
and sulfur dioxide (32).
Instruments have been fatricated for monitoring nitric oxide in
ambient air by reaction with 0 , and NO by reaction with atomic oxygen
j x
(33> 3U]• Field evaluation of these instruments will follow.
Optical techniques based on absorption of energy by pollutant
molecules in the ultraviolet, visible, infrared, or microwave regions
have found little application in ambient air rronitoring. An exception
i: - 46
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is the non-dispersive a rbon monoxide infrared analyzer. An infrared
fluorescent analyzer has. been developed for CO that has high sensitivity
and specificity (35). Cither pollutants existing at lower concentrations
do not absorb sufficient energy to permit utilization of other present
commercial types of NDIL1. atmospheric analyzers. Improvements can be
achieved by multiplexing (the simultaneous observation of multiple
spectral resolution elenents), which can be used to obtain higher
signal-to-noise ratios (36). Multiplexing can be obtained in a
variety of optical devices, including multiple-channel radiometers,
interferometers, dispersive matched-filter spectrometers, grating
spectrometers, and cross-correlation non-dispersive analyzers (36).
More use of this technique has been made in remote-tuned closed-path
instrumentation, but multiplexing can be used to advantage in both
types of applications.
In recent years, some of these optical techniques have been
developed with specific application for an,jient air analysis. These
approaches involve either differential spec'i rophotometry or correlation
spectroscopy. The technique of correlation spectrometry involves
molecular absorption, in which a portion of the ultraviolet or visible
spectrum containing vibrational-rotational band spectra is compared
with a replica of this spectral region stored within the spectrometer.
Point-sampling type correlation spectrometers for SCL and NCL with an
optical path length of 2.5 meters have been fabricated and evaluated
in Toronto and Los Angeles (37, 3#)»
The second-derivative spectrometer electromechanically processes
the transmission versus wavelength function to produce a signal that
is proportional to the second derivative of this function. This technique
results in enhancement of signal-to-noise ratio and improved specificity.
A spectrometer of this type has been fabricated to analyze nitric oxide,
ozone, sulfur dioxide, and nitrogen dioxide in the 190 to 400 nanometer
region (39). Sensitivities ranging from 0.003 ppm for NO and S0? to
II - 47
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0.02 ppm for N0? are reported for a 1-meter white cell with 20 passes.
Both techniques make possible greater specificity by taking advantage
of the details of band structure. They also provide somewhat improved
sensitivity. However, the electronic and optical systems utilized can
be involved and expensive. It is not clear whether these types of
optical systems will be; competitive in response characteristics, field
performance, or cost-size characteristics with the instruments discussed
previously for ambient air monitoring.
Another approach is the use of a folded laser beam with white-
cell optics. With a laser, a long narrow glass pipe could be used
rather than the usual large heavy steel tank (36, 40). To obtain the
sensitivities needed for ambient levels of pollutants, at least a 1-km
path is needed, requiring a 6-meter base length. Since both an
analytical and a reference wavelength are needed, tunable lasers are
highly desirable. The tunable semiconductor dioxide lasers, such as
the lead-tin-telluride jaser now under e\iluation, is attractive because
of its small size and extremely high resoli tion that results from
continuous tuning over several tenths of a wavenumber around 10 microns
(36, 4l)« Because of its small size, this type of laser plus a detector
with excellent sensitivity, such as the mercury-cadmium-telluride
detector in a common liquid nitrogen cooler can be used as the key
elements in a closed-path optical instrument (36). A spin-flip Raman
laser providing tunable infrared radiation has been used to measure
nitric oxide in the ppm range (42).
All of the instruments or concepts discussed have involved point
sampling; that is, the atmospheric sample is pulled into the instrument
through a probe or inlet line of some type. Such types of instruments
may or may not, integrate over time, depending on response characteristics
or deliberate provision for integration of the sample or the signal
over time. Integration over space is not involved, except as meteorological
conditions influence the flow of pollutants past the sampling site. The
II - 48
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measurements obtained are not necessarily representative of pollutant
levels over extended aroas of the city or over entire air quality
regions.
A completely different approach to ambient air analysis involves
the use of long-path or remote optical measurements. Such optical
instruments would provide the ability to integrate over space in two
or in three dimensions.
The Research and Monitoring Office of the Environmental Protection
has not only a program for development of point-sampling instrumentation,
but also a program for development and evaluation of long-path and remote
instrumentation. Correlation spectrometers have been evaluated in
several cities for long-path measurement of sulfur dioxide and nitrogen
dioxide, using near-groiend-level paths with two-ended systems utilizing
active sources of energy (38). Path lengths from 100 meters up to
1000 meters were used ir these measurements. In the work done in
Los Angeles, two path lengths were compared one a cross-freeway path
and the other an off-freeway path. Long-pati results were compared to
point-sampling results, but the experiment also whowed that point
sampling could be unrepresentative of the average pollutant concentrations
even in a 1000-meter path. These measurements can be limited by aerosol
scattering effects or excessive sunlight (38). An open-path circular-
filter-type infrared analyzer, programmed for ozone measurement but
capable of measuring other pollutants in the 7 to 14 micron range, has
been developed (43)- This instrument is designed to measure ozone
between 0.01 and 1 ppm at path lengths from 400 to 1600 meters. Another
investigation ue:;ng supported is concerned with the potential of a C0?
laser system for long-path measurement of ambient air pollutant
concentrations (44)-
The optical instruments discussed thus far involve either two-ended
systems, or use of reflectors over fixed path lengths. Ideally, the
open-path system of choice might involve a pulsed signal with ranging
capability. If such a system could be developed with sufficiently
II - 49
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extended range, it could' cover much of an urban area in three dimensions.
Such a system would prol -ibly require a highly developed pulsed laser
system with comples data-handling capacity. A lidar-type system of
this sorb has received some evaluation by several groups for estimating
total particulate loadings in the atmosphere (45 - 47)• Similar systems
do not presently exist for measurement of gaseous pollutant molecules.
The use of laser Raman spectroscopy offers possibilities, but sensitivities
appear marginal at present (48)• Considerable augmentation of the scale
of the present efforts will be necessary to develop practical systems
for routine monitoring activities.
Still another area of interest involves the use of remote optical
instruments mounted in aircraft. The instrumentation can be pointed
at the earth's surface to meaure the albedo of the multiple path of
sunlight passing through the atmosphere to the surface and reflected
upwards to the aircraft-mounted instrument. Correlation spectrometers
for sulfur dioxide and nitrogen dioxide i.^e been evaluated in flights
over several cities (38). This technique also has applicability to
monitoring of stack emissions and plumes (38). However, several problems
exist in applying the technique. In a clear atmosphere the equipaefct
tends to operate reasonably well, but scattering by aerosols limits use
of the equipment and also renders uncertain the appropriate path length
to include in the calculation. In addition, such aircraft measurements
are limited by any atmospheric conditions that interfere with flight
operations.
If aircraft operation of remote instrumentation is possible, various
earth-oriented satellite applications also are possible. Such satellites
would not offer the flexibility, accuracy, and general utility of aircraft
in taking measurements over urban areas of air quality regions. However,
satellites may have eventual utility for measuring long-lived pollutants
such as carbon monoxide "id submicron particulates on a global scale,
although, adequate measuring techniques are still lacking at the present.
NASA is supporting effort particularly for methods that analyze carbon
II - 50
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monoxide by utilizing both infrared correlation spectroscopy and non-
dispersive infrared techniques. The latter approach was selected as
applicable after a survay on numerous trace gas detection techniques
(49). Applications of optical techniques in the upper atmosphere of
the earth or to other planetary atmospheres will not be considered
in the discussion.
The chemiluminescence ozone, and the gas chromatographic carbon
monoxide and methane instruments have already been used in low-
concentration-level geophysical measurements (50, 51)• The flame
photometric sulfur oxide and the chemiluminescence nitrogen oxide
monitors may be usable for nonurban or rural measurements, but do not
presently have the sensitivity for geophysical measurements. The
initial emphasis has been on development of equipment capable of
continuously or periodically measuring pollutant concentrations in
samples of ambient air collected in a very short time interval. How-
ever, for urban measurements as well as rmnurban and geophysical
studies, integration of concentration over time periods of 1 to 24
hours is an alternative to the conversion oi continuous measurements
to averaged values for these periods by data reduction techniques.
Work is just being initiated on the possibility of utilizing several
of the available types of sensors for integrated measurements.
Monitoring capability is especially important for carbon monoxide,
sulfur dioxide, hydrocarbons, ozone, and nitrogen dioxide because air
quality standards for these widespread pollutants will be established
throughout the United States (52). In addit uon, a number of other
gases or vapors are of considerable concern or of potential concern.
These substances include hydrogen sulfide, organic sulfur compounds,
hydrogen fluoride, hydrochloric acid, chlorine, and nitric acid. With
the possible exception of hydrogen fluoride (and water-soluble fluorides)
the lack of data makes ~'t difficult to estimate the levels or wide-
spread prevalence of these substances.
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As already discussed, a sensitive and specific gas chromatographic
technique is now available for hydrogen sulfide and organic sulfur
compounds (26, 2?)« Hydrogen fluoride is generally measured as flouride
along with other water soluble fluorides. However, a fully satisfactory
monitoring instrument does not appear to be available. The ion-selective
fluoride electrode may have the greatest potential because it has been
reported to have acceptable selectivity and reproducibility (54)•
Colorimetric methods utilized have required considerable processing,
including distillation, because of poor specificity. The ion-selective
electrode has not yet been incorporated into an operational field
instrument.
No methods are available that have satisfactory specificity for
hydrochloric acid, chlorine, or nitric acid. Hydrogen chloride is
emitted from combustion of chlorine-containing coals and incineration
of chlorine-containing materials, particularly plastics, and this acid
may also be formed by atmospheric photo-oxidation of chlorinated solvents.
Therefore, hydrochloric acid may be more ^revaleht than is often assumed.
Nitric acid is a direct emission prodr it from nitric acid manu-
facturing, but a much more important source may be photochemical reactions.
Very little of the nitric oxide emitted is ever accounted for in the form
of particulate nitrate. Nitric acid has been shown to be an important
product of photo-oxidation of nitric oxide in the presence of hydro-
carbons in laboratory experiments (55)• The kinetic mechanisms usually
postulated for conversion of nitric oxide and nitrogen dioxide to
products also favor nitric acid formation. Because of a lack of an
acceptable technique for atmospheric analysis, we cannot assess the
importance or nitric acid as an atmospheric pollutant. Optical
techniques, incluiing open-path instrumentation, should offer
possibilities for measurement of nitric acid, hydrochloric acid,
chlorine, and hydrogen xluoride.
II - 52
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Thus far, the discussion has greatly emphasized inorganic pollutants.
In part, this reflects the development of air quality criteria for only
one group of volatile organic substances - nonmethane hydrocarbons (52).
The lack of additional differentiation among volatile organic substances
does not result so much from lack of laboratory analytical methods as
from lack of routine monitoring techniques.
Gas chromatographs with flame ionization detectors have been
utilized in mobile laboratories to analyze atmospheric samples for
identification and quantitation of 30 to 60 different aliphatic and
aromatic hydrocarbons (56, 57). The chromatographs have been used
both for periodic monitoring and for grab sampling. The number of
components analyzed has depended on the substrates used and the atmos-
pheric concentration levels. Process-type gas chromatographs for non-
methane hydrocarbons are in development.
Peroxyacetyl nitrate also has been analyzed by gas chromatography
with electron-capture detectors (58). Because nitrate is unstable,
grab sampling is not satisfactory; howevei, monitoring on a given site
can be conducted. Calibration problems and the lower stability of the
electron-capture detector considerably limit the utilization of this
technique by monitoring networks. Formaldehyde, acrolein, and aliphatic
aldehydes also have been analyzed in atmospheric samples by colorimetric
techniques (6). Results reported have involved manual sampling and
analysis. Colorimetric analyzers have been fabricated and used in some
field applications (59? 60). Unfortunately, these colorimetric analyzers,
and other analyzers basod on colorimetric te:hniques, would present
considerable problems in large-scale routine monitoring use because of
the need for reagent preparation and use of liquid flow systems, and
because of varying respcnse to individual aldehydes.
The monitoring that has been done for specific organics has been
done by a limited numbei of groups interested in improving understanding
of atmospheric chemistry or in identifying the contribution from various
emission sources to hydrocarbon composition. Air quality standards now
being established are not likely to require differentiation among these
organic species.
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Analysis of non-methane hydrocarbons has several fundamental
limitations: (l) the measurements cannot be utilized to determine
the effectiveness of control, over a given period, of any particular
source of organics; (2) response characteristics of the flame ioniza-
tion detector differ fo:~ various hydrocarbons; and (3) the flame
ionization detector doer> not respond to formaldehyde and shows reduced
response to other aldeh,'des.
Even a detailed gar> chromatographic analysis for hydrocarbons
will not make it possible to follow control of even the major sources
of hydrocarbon. This difficulty results from a lack of specific
hydrocarbons that can bo used as unique tracers of contributions from
individual emission sources. However, acetylene and ethylene can be
used as indicators of control of combustion sources. In downtown
high-traffic-density areas, these hydrocarbons also should serve as
indicators of the level of hydrocarbons from vehicular exhaust.
Ethylene measurements would be of direct interest in some areas because
of its plant-damage characteristics.
Some steps must be taken to optimize flame ionization detector
response to minimize deficiencies in response to individual hydro-
carbons in atmospheric .analysis. Calibration with a single saturated
hydrocarbon is the accepted procedure. Such a calibration limits the
accuracy of comparative measurements of atmospheres in which the hydro-
carbon composition varies.
There is a definite need to include aldehydes in the measurement
of volatile organics. Aldehydes can constitute a significant fraction
of the reactive organic substances present in atmospheric samples.
Better methods for monitoring atmospheric aldehydes are required,
however. Optical techniques warrant more consideration for their
potential in providing convenient means for monitoring aldehydes in
the atmosphere.
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Instrumentation for Measuring Atmospheric Particles
Particulate analysis is more complex and in some ways less
advanced than analysis of gaseous air pollutants. Certainly, there
is a clear lack of instruments for analyzing particulates by mass,
size, and chemical composition. The great bulk of available results
have been obtained by collecting samples on filters in the field and
then weighing and analysing the collected sample in the laboratory.
Particles larger than 10 microns settle readily, and they are usually
associated with settled dust and dirt. Particles in this size range
are deposited in the na sopharyngeal region of the respiratory tract
and do not tend to peneIrate effectively into the pulmonary and tracheo-
bronchial regions (6l). Consequently, these large particles have not
been associated with toxicologLcal action. Particles above 10 microns
also do not have significant effects on light scattering and on
visibility. Sampling for these large particles has been accomplished
with dustfall jars, adhesive coatings, cyclonic collectors (for
higher-volume samples), long horizontal turu .els (as fractional
elutriators), and various impactors (62). Dustfall jars appear as
satisfactory as more complex and expensive techniques are although
the dust-fall jar has poor time resolution. The justification for
the use of dustfalljars has decreased, however, since they have become
increasingly poor measures of particulate pollution as the level of
atmospheric particles smaller than 10 microns has increased. In view
of these circumstances, little justificatior exists for directing
effort toward development of instruments that can measure particles
larger than 10 microns.
Particles between 0.1 and 10 microns probably are those of the
greatest concern in air pollution. The particles in this size range
contribute most of the particle mass. These particles penetrate into
the pulmonary and tracheobronchial regions. The proportion of-the
particles that are between 0.1 and 1 micron is particularly important.
II - 55
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Particles in this size range are largely responsible for reduction
in visibility, and for haze and turbidity. Studies of physiological
response to particulate matter indicate that particles smaller than
1 micron can have greater irritant potency than larger particles (43)-
Measuring techniques for particles in the 0.1 to 10-micron range
have included the Volz sun photometer, the integrating nephelometer,
various other forward-scattering and right-angle-scattering instruments,
cascade impactors, electron microscopes and tape samplers (62). None
of these techniques is adequate for providing a quantitative measurement
of mass concentration of 0.1 to 10-micron particulates. Several of
these techniques have been research tools not primarily intended to
give an overall measure of mass concentration; nonetheless, they have
given valuable specialized measurements on particular characteristics
of particulates in this size range.
The tape sampler has received considerable use in the measurement
of suspended particulates. Visual color of the spots on the tape has
been compared with a standard gray scale. More frequently, reflectance
or transmittance measurements have been usec . Transmittance measure-
ments, however, have been shown to relate poorly to the mass of particulates.
Reflectance also is not ordinarily related to total suspended particulate
but to "dark suspended matter", inasmuch as reflectance is also a. function
of absorbance, and absorbance is a function of "color"'.' Both techniques
suffer from a number of complications related to variability in the
characteristics of the deposits. Neither technique can be considered
satisfactory for measurement of absolute cor :entrations of particulates,
but tape samplers can be used to obtain relative values. Careful
standardization is critical. Changes in the characteristics of the
particulates over periods of years at a site because of fuel changes
or control efforts may limit the usefulness of these measurements even
for obtaining relative values.
The integrating nephelometer has received considerable evaluation
in recent years in an attempt to relate its response to mass concentration
II - 56
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of suspended particulars (64-dV). This Instrument was designed to
measure meteorological i^ange, which in turn correlates well with
v- -.ual range. However, a close correspondence between nephelometer
response and mass concentration is obtained only if the particle-size
distribution and other particle characteristics remain constant.
Unfortunately, the experimental measurements themselves show this not
to be the case (68). A visual range of 7-5 miles can be associated
o
with mass concentrations ranging all the way from 50 to 200 ug/nr.
Such a range of mass concentrations represents the entire range of
annual geometric mean concentrations of suspended matter in urban areas.
Similarly, a visual range of 5 miles can be associated with suspended
particulate loadings ranging from 75 ug/m to 300 ug/nr. Such results
clearly indicate that nephelometer measurements are completely in-
adequate as a means of determing whether particulate emissions comply
or tend to comply with air quality standards for particulates. This
instrument certainly is useful, however, in its original purpose,
which is the measurement of meteorological or visual range. Since light
scattering is associated primarily with particles in the 0.1- to 1-
micron range, it would seem more useful to attempt to relate nephelo-
meter measurements to mass concentration in the 0.1- to 1-micron range
than to total suspended particulates.
The equipment that has received the greatest use in particulate
measurement has been the high-volume sampler (62). This device
necessitates the replacement of filters that must be transported to
the laboratory for weighing and chemical analysis. Ordinarily, a 24-
hour-average sample is obtained. When such integrated total weights
of suspended particulate measurement has been the high-volume sampler
(62). This device necessitates the replacement of filters that must
be transported to the laboratory for weights of suspended particulate
matter are desired, the high-volume sampler probably is an adequate
device. However, this sampler can collect particules well above 10
microns and may not be too efficient in collecting particles approaching
0.1 micron. In addition, the sampling rate is sensitive to the mass
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of material collected. It is in the utilization of high-volume samples
for subsequent chemical analysis that a multitude of problems occur.
The glass fiber filter medium as ordinarily used gives high blank
readin^'" for a considerable number of cations and anions. Furthermore,
i«.-'.ctions can occur on the filter medium between collected materials-
Oxidation or volatization of some collected substances can and does
occur. Other filter materials can be used, particularly for special
analytical applications, but such filter materials usually have
limitations associated with their use as well.
It should be apparent that these sampling problems cause greater
obstacles to overall analytical techniques themselves. Conversely,
it seems futile to expend much effort on improving analytical techniques
if the greater source of uncertainty results from the sampling technique
itself.
The Anderson sampler has received considerable use as a particle-
sizing device. Although materials collected on the various stages must
be returned to the laboratory for weighing or analysis, this sampler
can serve as a useful interim approach for both mass and composition
measurements.
A number of types of instruments ought to be developed for the
measurement of particulates. A continuous or periodic monitoring
instrument capable of measuring the mass concentration of aerosols
below 10 microns is needed. An instrument has been developed that
uses an electrostatic precipitator to deposit aerosol particles
directly onto a piezoelectric quartz crystal microbalance (72). The
balance is sensitive enough to permit measurements of incremental mass
for time periods of less than 1 minute. Collection can be significantly
influenced by sorption or desorption of water vapor, but this effect
can be reduced by use of a dual-crystal detector. Adhesion of larger
particles depends on the composition of the particulate and the
relative humidity. Addition of a surface active agent to the flow
samples can help minimize this difficulty. Because of these possible
limitations, such equipment requires careful field evaluation and
comparison with normal particle-sizing collection techniques (69-71).
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Equipment capable of periodic monitoring of particle-size
distribution by mass concentration aluo is required. An investi-
gation is underway of a new cascade impactor concept for particle-
^j.ze i'ractionation, in which by beta-ray attenuation is used to
measure material collected on a filter tape.
Cn view of the difficulties in filter col .ection and chemical
analysis, development of on—site chemical anal/zers for various
chemical species in perticulate matter may be justified. Aside
from monitoring needs improvement of our knowledge of gas aerosol
transformation in the ambient atmosphere requires instruments capable
of the diurnal monitoring of such species as sulfuric acid, total
particulate sulfate, particulate nitrate, and organic aerosol. All
of these substances contribute to the loading of particulates in the
3.1 to 1 microns range. Research studies using particle-sizing
samplers alro have identified lead, sulfate, nitrate, carbon-containing
species and ammonium and chloride ions as constituents in the 0.1- to
1-micron range (69-71» 73, 74)- To properly associate visibility with
air pollution contro effectiveness, both the total mass concentration
within the 0.1— to 1-micron range and the contribution of these chemical
species to the mass concentration must be known. Of course, the direct
association with visibility also involves computing the on-site contri-
butions of individual species based not only on mass and size
distribution but also on optical characteristics of the particles.
Despite emphasis on automated field methods, laboratory procedures
will continue to be useful in particle-size and morphological analysis
of airborne particles (75»7°)« For example, optical and electron
microscopy can be used for particle sizing. These techniques, along
with x-ray diffraction and other measurements of physical properties,
have been used to characterize a wide variety of types of particles.
An atlas of photomicrographs of various airborne particles is
available to aid in microscopic identification (77).
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The eleciron microprobe hns boeri used for identification and for
estimation oi relative concentration of a variety of elements including
Al, i'd, P, S, Cl, K, Ca, V, Fe, Ni, Cu, Zn, Br, La, Ce, and Pb in
airborne particles (78-79). In addition, MOJiport filters and
v ..i-ium disks have been scanned by area for individual elements.
Lead has been found i ssociated with bromide ard chlorine, but samples
also have been scanned in which the lead is present with sulfate.
Particles can be located in which no elements can be identified in
the X—ray distribution patterns, probably because they contain carbon
and other lower-atomic-weight elements.
The monitoring of a variety of hazardous or potentially hazardous
elements, including Be, Hq, As, Cd, V, and Mn may require the develop-
ment on on-site analyzers. For this purpose, X-ray fluorescence
techniques should have potential. Work is underway to estimate better
the potential of X-ray fluorescence for analysis of airborne particulate
fractions. Atomic absorption already has been shown to have potential
for continuous analysis of certain elements in air, such as lead (80).
Such equipment would allow sampling each 24 hours or oftener, 7 days
a week, instead of the more frequent analysis ordinarily associated
with filter collections and laboratory analysis. A monitoring tech-
nique for various elements also may be desired for analysis of some
types of stationary emissions.
Elemental Analysis
Particulate samples are usually analyzed 3'or the elements after
collection on a filter. Contamination of the filter media with trace
quantities of the elements is a commo i limitation on analysis. The
glass fiber filter most commonly used for collection is not satisfactory
Tor trace analysis for a number of metals because of such contamination.
Cther substrates, such as polystyrene membrance of Millipore filters,
have been used but still are far from completely adequate. For a few
elements such as mercury, other collection techniques are used, such
as amalgamation or use of gas bullers.
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Methods of analysis utilized included colorimetry for a few
elements. Usually physical techniques including optical emission
spectroscopy, atomic absorption spectrophotometry, neutron activation
an-".ysis, X-ray fluorometry, spark-source mass spectroscopy, and
stripping voltammetry have been used for elemental analysis. The
status of techniques available through 1966 has been reviewed with
emphasis on wet chemical techniques, ring over methods and atomic
absorption spectrophotometry (81).
Optical emission spectroscopy has been used for elemental analysis
over the past 15 years in Federal monitoring activities. This spectro-
graphic technique has been applied to analysis of 16 elements - As,
Be, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, Ti, V, and Zn (82).
This method involves considerable analytical skill but it is still
only semi-quantitative, lacks sensitivity for a number of elements,
and is limited by blanks in the filter substrate.
Atomic absorption is a more quantitative and specific technique
and is very sensitive for some elements. This technique can be used
for As, Be, Na, K, Ca, Mg, Ba, Cd, V, Co, Cu, Zn, Ag, Ni, and Pb,
(70, 83-85). The method is limited by the availability of hollow-
cathode lamps. A number of these elements have been measured after
particle-sizing of airborne particulates (70). Atmospheric precipitation
samples have been analysed for PB, Zn, Cu, Fe, Mn, and Ni (86).
The thermal neutron-activation analysis of particulate matter in
air has received increased use in recent years (87-88). Scintillation
counting using a thallium-doped Nal crystal on samples on cellulose
fiber as utilized to determine Al, V, Mn, Na, Cl, and Br. In much more
ambitious use of neutron activation analysis, airborne particulate
samples were collected on polystyrene filters and counted by means of
a lithium-doped De detector. The procedure permits determination of
up to 33 elements provided that 5-minute irradiations are utilized
with 3- and 15-minute cooling periods and 2- to 5-hour irradiation
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with a 20- to 3C-hour radiation ( 20- to 30-day cooling period (89)).
Even with this scheme, most of the low-molecular-weight elements
cannot be analyzed. The sensitivities for a number of the elements
are martial or inadequate because of various limitations, including
Terence of other substances in the sample or a high blank value.
Included in the group of elements analyzed by this method are Mg, S,
Cl, Ti, Ni, and Ag. Determination of Li, Be, B, C, N, 0. F, Si, and
P could not be made. Therefore, only a few elements lighter than K
could be analyzed. In addition Pb and Cd, biologically important
elements that occur in airborne particulate matter, are not included
in the scheme. A number of the elements that can be measured are not
presently of concern biologically nor do they contribute significantly
to the mass of particulates. These elements include' Ga, La, Sm, Eu,
An, Sc, Ce, Co, and Th. Elements such as Cr, Fe, Ni, Zn, Se, Sb, and
Hg arc determinable only after a 20- to 30-day decay period. Therefore,
although this neutron-activation analysis scheme in principle appears
very attractive, in practice it can only be applied with one or more
other analytical techniques if determination of a range of biologically
important elements or a mass balance is desired.
A particularly interesting study made recently of elemental
analysis of particulates included use of optical emission spectrography
parts-source mass spectrography, X-ray fluorescence, atomic absorption,
CHN analysis, and chlorine analysis by a colorimetric technique (79).
By this means, 77 elements could be determined or estimated in parti-
culates collected in Cincinnati, Denver, St. Louis, Washington,
Chicago, and Philadelphia. Bound oxygen could not be included in
this analytical scheme. This study is one of the few that permits
any evaluation of analytical results from two or more methods on the
same samples. The agreement was good between the analyses by atomic
absorption and X-ray fluorescence for Ca, Fe, Cu, and Zn, often being
within 20 percent or less of each other. The agreement was not as
close for K and Pb in some samples. "When the analyses for Cu and Zu
by optical emission spectrographic technique were compared with those
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by atomic absorption of X-ray fluorescence, the values obtained by
emission spectrography averaged factor of two to three lower. The
Fe analyses by the optical emission spectrographic technique also
a"' raged appreciably lower than those by atomic absorption or X-ray
fluorescence.
It is likely that even with additional improvements in these
techniques, at least two if not three different analytical techniques
will be required to cover the range of elements of interest with
adequate sensitivity. It also would seem of considerable importance
to conduct concurrently some additional comparisons of each of the
several techniques for elemental analyses of the same sets of
airborne particulate samples. If confidence can be placed in these
analyses being correct, on an absolute basis, within 20 to 30 percent,
the reliability of each of the methods applicable to each element of
interest must be ascertained.
Anion Analysis
Analyses for sulfate and nitrate are routinely made on bulk
particulate samples collected on the high-volume sampler at urban
and nonurban sites (82, 95» 96). Sulfate is determined by the
methylthymnol blue method by means of an autoanalyzer (96).
Nitrate is assayed colorimetrically following reduction to nitrite
by alkaline hydrazine (96). In investigations on the particle-size
distribution of sulfate, several analytical procedures have been
used. In one of these investigations, high-temperature reduction of
sulfate to hydrogen sulfide was utilized, followed by an iodometric,
microcoulometric titration for the hydrogen sulfide (74)• In other
work (69-97) a modified turbidimetric procedure was used to analyze
the size-fractionated material from an Anderson sampler (98). Nitrate
was also determined colorimetrioally after reduction following particle
sizing (71). Phosphate and chloride also have been analyzed colori-
metrically after particle sizing (71).
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Organic Particulates
A considerable amount of analytical effort has gone into the
measurement of various types of organic substances in particulate
rnattp* Polynuclear aromatic hydrocarbons, particularly benzo (a)
i-ene, have received the most attention. Certain of the procedures
involving column chromatography followed by spectrophotometric
analysis have interference problems associated with them. Paper
chromatography, but more usually thin layer chromatography, have
received considerable attention as separation techniques. Spectro-
polynuclear aromatic hydrocarbons, aza heterocyclics, and polynuclear
ring carbonyls after use of column and thin-layer chromatography. Gas
chromatography has been applied to n-alkanes in airborne particulates
as well as to polynuclear aromatic hydrocarbons. However, adequate
separation of benzo (a) pyrene from benzo (e) pyrene and proylene has
been a problem in applying gas chromatographic procedures to the
analysis of airborne particulates. The details of these developments
have been reviewed up to 1968 in several publications (90, 91)• The
status of work on pesticides, nonvolatile fatty acids and phenols
is also considered in one of these reviews (91)•
More recently, a simple and rapid procedure has been developed
for the determination of benzo (a) pyrene, benz (c) acridines and
7H-benz (de) anthracen-7-one (92). Benzene extracts were separated
by one-dimensional thin-layer chromatography followed by analysis of
benzo (a) pyrene by spectrophotometry or spectrophotofluoremetry and
the benz (c) acridines and 7 H-benz (d) anthracen-7-one in trifluoro-
acetic acid, by spectrofluorometry. The procedure was applied to 6—
month composites from 52 cities. Most analyses for polycyclic organic
materials are applied to 24-hour integrated samples or composites
representing even longer integration times. A sensitive procedure,
requiring less than 20 minutes, that involves thin-layer chromatography
and direct fluorometric measurement was applied to 3-hour sequential
air samples for analysis of 7H-benz (de) anthra-can-7-one and
phenalen-1-one (93).
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Little recent work has been done.1 on pesticides in air. Samples
collected at nine urban and rural sit.es were analysed for 19 pesticides
and their metabolites (94). Chlorinated pesticides were determined
<">- two different gas chromatographic columns utilizing electron-
capture detectors, while organophosphate pesticides were determined
on two different gas chromatographic columns utilizing flame photo-
metric detectors. Only p, p -DDT and 1, p -DDT were found at all
locations.
STATIONARY SOURCE EMISSION MEASUREMENTS
Source of pollutants among stationary sources very from thermal
power plants and incinerators to cement plants and petroleum refineries.
Pollutants associated with such sources include particulates, sulfur
oxides and nitrogen oxides, but also include fluorides, carbon
monoxide, and organics.
Emissions of pollutants from stationary sources may involve flue
gases or other vented gases. For some types of extended stationary
sources analytical measurements would have to be made by a network of
sampling sites or by lor.g-path techniques. Such problems have not
received much attention in practice. The present approach appears
to be the use of the best available control technology with no
continuing attempt after insta]lation to determine compliance in
terms of measurement of pollutant concentration.
For flue gases or vented [;ases up stacks techniques of measure-
ment do exist. In such situatrions it is important not only to measure
the pollutants, but also the gas flow velocity, excess air, moisture,
etc. The sampling technique is of great importance and it must be
suitable for the specific application. If sampling problems are
handled adequately, the analytical measurement requirements can be
simplified.
The analytical measurements of pollutants can be accomplished by
at least four approaches, (l) intermittant sampling on site with manual
analysis in the laboratory, (2) continual instrumental analysis of
pollutants collected through probes, (3) in-stack instrumentation,
(4) remote instrumental techniques. The second group of instrumental
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methods would include instruments capable of operating at emission
concentration levels and the use of a proper sampling addition interface
permitting use of ambient air type instrumentation. The in-stack
instruments presumably integrate so that probing the stack configuration
".' not necessary.
Remote instrumentation cannot be utilized continually, but this
class of instrument can be used for rapid surveys and checking compliance.
The problem of positioning instruments or probes in stacks is eliminated.
Problems associated with the correct relationship between in-stack
particle concentration and particle size distribution to that emitted
out of the stack into diluation air also are avoided. However, the
practical development and utilization of remote optical instruments
with the appropriate characteristics is difficult, scientifically
and technologically.
Manual Procedures
Methods in common use for measurement of pollutants from stationary
sources of emissions ha\e been manual rather than instrumental. Filters,
impingers, evacuate flasks and condensation are the collection techniques
commonly used. To express pollutant mass loadings and relate results
to process variables additional measurements are required. These
measurements include stack gas velocity with a pitot tube, moisture
in-stack gases determined gravimetrically on condensate, excess air
by Orsat analysis and carbon dioxide by the non-dispersive infrared
spectrometric method (99~10l).
Sulfur dioxide usually is determined by collection of the flue
gas in impingers containing hydrogen peroxide (102-105). The sulfur
dioxide is oxidized to sulfate and analyzed after reaction with barium
chloroanilate colorimetrically at 530 mu in terms of the chloroanilate
ion. A second procedure often used involves determination of the sulfate
by the barium perchlorate thorium titration method (102, 103). The
sulfur trioxide or sulfuric acid mist after separation by filter
collection is determined by the same procedures.
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Cations such as Al+3, C+2, F+3, Pb+, Cu+ , and Zn+ produce negative
interference in the colorimetrJe procedure by precipitating chloranilate
Ion from solution. Thes< intei L'erencey can be minimised by filtering
i v flue ga::> with glaus v.ool al the probe and pretreating the solution
with a cation resin. Ani JYIS causing interference are not likely to
be present in flue gases. The titration with barium perchorate is
interfered with by caticns such as K+, Na+, NH, by reducing the
volume of titrant needed. Cationic interferences are minimized by
use of a particulate filter in the probe and by percolation of the
collected solutions through a cation exchange column. Anions which
can co-exist in the collected solutions such as nitrate, chloride
and fluoride can interfere also.
These sulfur dioxide analytical procedures have practical ranges
from 10 to 3000 ppm by volume. The sensitivities are 10 ppm for 25
to 30 liter samples. The precisions are about £ 3$ at 1$00 ppm. For
sulfur acio aerosol the range is 10 to 300 ppm with a precision at
JO ppm of + 5$.
Nitrogen oxides often are collected from flue gases in an
evacuated flask containir g dilute sulfuric acid hydrogen perioxide
absorbing solution. The nitric oxide or nitrogen dioxide are oxidized
to nitric acid which is measured colorimetrically at 420 mu as nitro-
phenol disulfonic acid (H06). This technique has a range of from 15
to 1500 ppms by volume with a sensitivity of 1.5 ppm. Halogens interfere
in this procedure.
In common practice particulates are measured gravimetrically after
removal of uncombined water (107-109). The particulate is removed from
the flowing gas stream urder isokinetic conditions by filtration and
condensation. Impinger collection is used as part of this procedure
with extract of organic j articulate from the impinger solution with
chloroform and ethel ethfr. Aceton washing of the probe and filter
holder also is included :n the procedure. The total particulate weight
of aqueous and organic s£ mple components is obtained by totaling the
weights of components. Total sample volume or stack velocity and other
parameters are utilized in calculating particulate mass in stack gas.
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Continual Instruments for Sampling through Probes
A number of instruments based on optical techniques have potential
for use at stack gas pollutant concentration levels. Non-dispersive
infra-'--d analyzers or ultraviolet analyzers have been designed for
bili'ur dioxide, nitrogen dioxide and carbon monoxide. Optical tech-
niques has received attention for visibility of stack gases in plumes.
Portable electro-chemical transducers recently developed have potential
for use in measurement of sulfur dioxide and nitrogen oxides in stack
gases (29). The instruments utilizing the chemiluminescent reaction
of ozone with nitric oxide could be utilized for measurement of nitric
oxide in stacks (22,31-33).
Gas chromatographic instruments have received considerable
evaluation for sulfur dioxide, hydrogen sulfide and organic sulfur
gases in Kraft mill effluents (26, 27, 110-112). Gas chromatographic
analyzers also could be utilized to measure carbon monoxide and sulfur
dioxide in various stack gases.
A source sampling technique for particulate and gaseous fluorides
involves use of a heated glass probe to convert hydrogen fluoride to
silicon tetrafluoride (313)» This type of sampling procedure has been
used with a fluoride-se]ective ion electrode to analyze water-soluble
fluorides in stack gase;..
An attractive samp]ing approach would be to convert the stack gases
by dilution and cooling to condition approaching these in ambient air
analysis. The same instruments could be used as for air quality measure-
ments. This approach would considerably reduce the number of types of
instruments in use, calibration requirements and maintenance problems.
Studies are needed on the approached sampling interfaces to provide
dilution and cooling without changing pollutant composition. "Work is
in progress on the evaluation of sulfuric oxide and nitrogen oxide
analyzers for stack gases.
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In-Stack Instrumentation
Instruments capable of operating within the stack itself usually
have been based on optics! principles. Such equipment must be built
to withstand dust, heat, corrosion and vibration. Thermal gradients
can cause considerable problems in optical alignments. Calibration
of such instruments requires spectra under experimental conditions
closely similating stack conditions.
Remote Stack Instrumentation
Remote sensing techniques offer several advantages over the
traditional methods of sampling through a probe introduces into a
source of emissions. These advantages are as follows: (l) more
representative sampling by virtue of spectral integration across
the diameter of a stack plume, (2) no need for interfacing between
stack and analyzer with probes and sample conditions (3) capability
of measuring across an extended source such as an oil refinery.
Electro-optical techniques can be utilized remotely to charac-
terize particulate and gaseous emissions. The use of "Lidar" systems
for determining the opacity of plumes from power plants has received
considerable attention (114-117)- A study of the optical properties
of such plumes concluded that the optical transmission of the plume
best characterize the aerosol loading in emissions. A "Lidar" system
has been fabricated as a research tool for field studies. More
practical field equipment will probably utilize the signal backscattered
from the plume aerosol rather than the signal backscattered from the
ambient air beyond the plume. Such equipment would use a low powered
laser. Mass loading measurements of aerosols in plumes also can be
made by "Lidar" but interpretation of the signal would require measure-
ments on other characteristics including particle size distribution.
The measurement of gases such as sulfur dioxide can be approached
by use of ultraviolet transmission, infrared emission or Raman
scattering. Field evaluations have been made utilizing correlation
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spectroscopy in the ultraviolet (38) and will be made with high
resolution infrared emission spectroscopy. Nitric oxide presents
a particularly difficult problem because of the overlap of the nitric
oxide b?nds in the 5 u region by water vapor bands.
rtaman scattering provides a means of measuring nitric oxide with
serious interference by other stack gas constituents. In a preliminary
feasibility study insufficient signal to noise ratio was available
(118). Improvements in (S/N) can be achieved by use of resonance
Raman scatter and by fluorescent scatter techniques.
Detailed analysis of particulates in stationary source emissions
for elements or compounds present many of the same problems as those
already discussed for atmospheric analysis. Elemental analysis has
been limited until the recent increase in concern about trace metals.
However, available techniques already discussed for atmospheric par-
ticipate samples appear adequate for most stationary source applications.
A reasonably extensive sampling and analysis program was conducted some
years ago to analyze up to 10 polynuclear aromatic hydrocarbons in
samples collected from a variety of combustion processes and industrial
processes (119). Analyses were made by ultraviolet-visible spectro-
photometry on the benzene soluble fraction of the samples following
separations by column chromatography.
MOBILE SOURCE EMISSION MEASUREMENTS
Research measurements of the detailed composition of emissions
of motor vehicles have been made for at least 1$ years although
emission standards for hydrocarbons in blowby gases were not promul-
gated in California until 1963 and for exhaust hydrocarbons and carbon
monoxide in 1966 in California and in 19°8 for the U.S. Subsequently,
nitrogen oxide standards have been established. Much more restrictive
standards for hydrocarbons, carbon monoxide and nitrogen oxides will
apply to 1975 and 1976 model year vehicles. Evaporative loss controls
also have been established. The limiting factor on implementing
standards has not been analytical methods, but control technology
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applicable to mass production vehicles. The original techniques
used for hydrocarbons, carbon monoxide and nitrogen oxides involved
use of non-dispersive ini'rared analysers. The infrared analyzers
for nitrogen oxides have suffered from water vapor interference as
irfell as limitation in sensitivity.
Many techniques have been applied for detailed analysis of
hydrogen emissions included mass spectroscopy, dispersive infrared
analysis, and by conlometric and colorimetric methods (6). Gas
chromotography was applied to automobile emissions shortly after its
first use in the U.S. However, thermal conductivity detectors were
limited in sensitivity and suffered from water vapor and carbon
dioxide interference. Chemical pretreatraent to remove interferences
and concentration techniques greatly complicated the practical
application of gas chromotography to automobile exhaust emissions
in the late 1950's. In the early 19oO's, the application of flame
ionization detectors eliminated these earlier limitations and
accelerated the use of gas chromatography to measure the detailed
hydrocarbon composition of automotive emissions (120, 121). With gas
chromotographic capability well established other analytical methods
have not been utilized in recent years. The flame ionization analyzer
has replaced the non-dispensive infrared analyzer as the motor vehicle
certification technique for hydrocarbons. The non-dispersive infrared
technique was of somewhat limited sensitivity for the more restrictive
standards and its response was depended on composition in an undesirable
manner.
Substructive columns have been used for analysis paraffinic,
elefinic, and aromatic hydrocarbons in vehicle emissions using a
flame ionization analyzer (122). This technique provides a more
rapid approach to class analysis of emission than does gas
chromotography.
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The \ise of open-tubular columns combined with solid absorbant or
packed columns combined with temperature programming makes it possible
to make about any analys Ls for individual hydrocarbons in emissions
desired. Considerable work has been done applying gas chromotographic
+ -••Cliques to organic oxygenates in exhaust. Recently a chemical
ionization mass spectrometer has been demonstrated to be capable of
measuring a number of aldehydes and ketones in exhaust. Work also
has been done on an electrochemical approach to aldehyde analysis,
but this technique is not far advanced.
Nitrogen oxide analysis primarily for nitric oxide has been done
by several other analytical techniques in addition to the non-dispersive
infrared analyzer. These other approaches included use of an oxidizing
step prior to colorimetric analysis or use of an ultraviolet analyzer.
A mass spectrometric analyzer for nitric oxide also was developed.
More recently the need to measure the lower concentrations of nitric
oxide required by future standards with use of constant total volume
samples has stimulated development of more sensitive analyzers.
Electrochemical and particularly chemiluminescent types of analyzers
have received recent evaluation.
The chemiluminescenb analyzers involving gas titration of nitric
oxide with ozone are highly specific, very sensitive and have very
rapid response times. A thermal decomposition stage has been used to
decompose any nitrogen dioxide to nitric oxide. A closely related
technique involves gas titration with atomic oxygen which results
in equal responses for nitric oxide and nitrogen dioxide.
The non-dispersive infrared analyzer for carbon monoxide has had
adequate sensitivity, specificity and speed of response of vehicle
emission applications. Therefore, there has not been much incentive
to develop other analyzers. Gas chromotographic analysis for carbon
monoxide and the recent fluorescent infrared techniques provide more .
sensitivity if needed.
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All of the instruments or methods discussed previously have been
developed either for research, certii'ication or surveillance needs.
Inspection of motor vehicles or production line testing requires
simple and inexpensive instruments. Some of the instruments discussed
are useable for these purposes although more expensive than desired.
Catalytic techniques have been shown to have potential. A simple,
rapid response optical instrument of moverate cost also has much appeal.
Considerable effort has gone into analysis of oxygenated hydrocarbons
particularly aldehydes and ketones. In internal combustion engine ex-
haust (6, 120, 123, 124), gas chromatographic and colorimetric methods
have been emphasized. Phenols also have received attention as products
in automobile exhuast (125, 126) by chromatography and colorimetric
techniques.
Polynuclear aromatic substances particularly the hydrocarbons have
been the subject of several measurement projects on automobile exhaust (9l)«
The work cited on polynuclear aromatic hydrocarbons for stationary
sources also included analyses for passenger cars and trucks (119).
Recently additional work has been done assiciatin polynuclear aromatic
substances and phenol:; w:i th fuels and fuel additives and engine variables
(127). The presence of aza heterocyclic hydrocarbons in automobile
exhaust has been demonstrated (128).
Earlier work on particulates in automobile exhaust was concerned
with amounts of lead-containing particles (129). During the same period
lead was determined polarographically on each of a series of particle
sized fractions from the Anderson Sampler, the Goetz spectrometer and
other devices from auto exhaust (30). Total particulate and benzene-
soluble particulates have been measured in two investigations (131, 132)
on exhaust from a number of passenger vehicles and trucks. Auto exhaust
particulates after size fraction atom in an Anderson Sampler has been
analyzed for lead, nitrate, sulfate and chloride by atomic absorption
and by nephelometric or colorimetric procedures for the anions (133).
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The ratio of water soluble to water-insoluble lead also were compared.
An Anderson sampler as well as a constant volume sampler were used to
obtain total particulate and size-fraction atom with analysis for lead,
iron ?-" d zinc by atomic absorption and bromine by neutron activation
\i3A). Both leaded and non-leaded fuels were utilized. A tunnel type
sampling system capable of sampling auto exhaust for particulate matter
under realistic operating conditions has been developed (135 )• This
system was utilized with Andersen and Monsanto impactors to do light
particle size; distributions as a function of vehicle operation conditions
and driving history (135). A similar sampling system was used in a
more comprehensive study of composition of particulate and gases with
fuels with various tetracthyl lead contents (136). Total particulate
weight, particle size distribution of particulate, metal analysis on
exhaust particulate as well as fuel and engine oil by optical emission
spectroscopy, chlorine and bromine by neutron activation, particle
chromatomization by electron and light microscopy, and organics by
mass spectrometric and ultraviolet fluorescent analysis were the
measuring techniques applied to the particulate fraction of the
auto exhaust (136).
Diesel exhaust emissions usually are considered of concern
because of smoke and odoi- problems in the vicinity of individual
diesel vehicles. Levels of carbon monoxide are very low from diesels
(137)- Hydrocarbon concentration levels can vary widely (137).
Because of the higher molecular weight of diesel fuels the combined
emissions of fuel components, low molecular cracked hydrocarbons as
well as partial oxygenated organic products presents a substantial
analytical problem (120). A portion of these organic components are
responsible for the odors associated with diesel exhaust emissions
(188-140). Nitrogen oxides also can vary considerably in diesel
emissions overlapping the concentration levels produced by vehicles
with spark ignition internal combustion engines (137)• Polynuclear
aromatic hydrocarbons also have been measured at substantial
concentration levels in diesel exhaust emissions (1/4-)•
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Measurement of the concentration levels of a number of components
such as carbon monoxide, nitrogen oxides, low molecular weight hydro-
carbons and polynuclear aromatic hydrocarbons do not present substan-
•"• '-dlly different analytical requirements from those well established
for spark ignition internal combustion engines. Sampling and analysis
of fuel hydrocarbons and their partial oxygenated products still present
opportunities for analytical activity (120). Although substantial
progress has been made in recent years on identification of the odorous
components of diesel exhaust much more analytical work is still needed (140).
Considerable use was made in earlier work by Scott research
laboratories of dispersive infrared measurements for carbon monoxide,
carbon dioxide, nitrogen oxides and some hydrocarbons (138)• Non-disperse
infrared instruments were used in Bureau of Mines investigations for
carbon monoxide and nitric oxide while nitrogen dioxide was measured
with a non-dispersive ultraviolet analyzer (137). Colorimetric methods
have been used for nitrogen oxides, formaldehyde, aerolan and total
aliphatic aldehydes (138). Gas chromotography has been used for
analysis of hydrocarbons in combination with column chromotography
with identification by mass spectrometry for odor components (140)«
Considerable progress has been made by this combination of techniques
when applied to the oilj'-kerosine odor fraction and similar techniques
are being applied Lo the smoky-burnt fraction. Column chromotography
combined with fluorescence spectroscopy has-been used to identify and
measure a number of polynuclear aromatic hydrocarbons in diesel exhaust
emissions (141 )•
The use of high molecular weight fuels presents a special problem
with respect to the actual form of the higher molecular weight products
upon emission. These materials may be present in the atmosphere as
vapors, as finely divided organic aerosol or as large droplets that
settle to the ground rapidly. Additional investigation is needed to
properly define this situation under realistic operating conditions.
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While smoke and odor have been the main c oncern from the
standpoint of concern about regulations, other emissions may well
have to be included in emission regulations in the future. If
emissions from the passenger vehicle equipped with spark ignition
i i - A-nal combustion engines are very effectively controlled by the
middle 1970's, the residue contributions from other propulsions
systems such as the diesel engine may well become of greater
concern.
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TABLE I
Air Pollution Program Elements Requiring Instrumentation and
y .^surements Development, Evaluation, and Stai.dardization
1. Air quality surveillance networks
2. Atmospheric and Plume Research Investigations
3. Biological effects field investigations
4. Air quality standards
5. Motor vehicle emission composition investigations
6. Motor vehicle certification and production line testing
7. Surveillance of production vehicles with mileage accumulation
8. Investigation of stationary source emissions composition
9. Stationary source emission standards
10. Determination of compliance with emission standards
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TABLE II
CRITERIA FOR AIR MONITORING INSTRUMENTATION
1. Compatibility with sampling system
2. Sensitivity sufficient to meet monitoring application
3. Specificity of response to pollutant of interest
4. Adequacy of response time for application
5. Simplicity of construction and operation
6. Reliability and reproducibility of operation
7. Compatibility with data handling equipment
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STATE OF THE ART IN NOISE MONITORING
Elizabeth Cuadra
Deputy for Program Development
Office of Noise Abatement and Control
Environmental Protection Agency
INTRODUCTION
This paper has been prepared specifically for presentation to an
internal EPA working session on environmental monitoring, for the pur-
pose of providing the other attendees with a brief introduction to the
state-of-the-art in noise monitoring. Therefore, the depth and degree
of detail have been purposely limited in order to provide the breadth
of scope appropriate to an introductory paper.
In Environmental Protection Agency usage, the definition of the
word "monitoring" is extremely broad, and encompasses such activities
as source emission monitoring, monitoring of effects upon receptors,
and a variety of other functions in addition to the traditional con-
cept of monitoring the physical or chemical characteristics of the
ambient atmosphere or medium. EPA planning appropriate to a national
noise abatement program effort would necessarily include significant
amounts of effort in these other types of monitoring.
For example, special field studies should be carried out to assess
the suspected health effects of extreme community noise environments,
to ascertain suitable criteria for noise limitation in outdoor rec-
reational spaces, to determine the actual extent of hearing impair-
ment among the general population, and to determine the typical noise
exposures of individuals among the population. However, this paper
restricts its attention to only one of the major subdivisions of noise
monitoring: the ambient environment itself. Even with this restriction
in scope, the present treatment is necessarily superficial and the
reader's attention is invited to the list of selected references at the
end of this paper, which is provided as an aid to further study.
ELEMENTS OF NOISE ABATEMENT/PREVENTION
Before we consider the details of the monitoring process, it is
helpful to consider the elements of any noise abatement or prevention
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program in terms oi a simplified logic model. Figure 1 shows the
three basic elements of any noise prevention design problem: the
noise source itself, the propagation path between the source and the
receiver of the noise (which in most cases are people, and in some
<>ses, may be wildlife or other mixed ecological systems). Any compre-
hensive prevention or abatement program, to be successful, must consider
all three of these elements and their relationships to each other.
While real world noise problems are comprised of many sources causing
the total noise environment that surrounds each individual receptor,
this simplified model provides a useful logic device.
Figure 2 shows the same source-path-receiver model, accompanied
by examples of the technical solutions appropriate at each potential
intervention point. The role of the receiver in the model is to provide
us with the criteria information necessary to establish design limits
for the noise environment, which will vary according to the use of the
space (e.g., outdoor urban area, outdoor wilderness area, urban resi-
dential area, commercial area, etc.). There are two available points
of intervention where actions can be taken to prevent noise from reach-
ing the receiver which would be in excess of the established design
limits: at the source and in the propagation path.
Intervention at the source, of course, corresponds to providing
quieter motorcycles and vacuum cleaners, controlling the extent of the
"noise footprint" of an airport, and designing freeways and other
ground transportation elements to minimize the extent of their noise
impact on the adjacent neighborhoods. Technical interventions in the
propagation path include the provision of adequate distance between
noise sources and receivers, taking advantage of natural terrain
barriers, and the provision of noise resistant barriers (such as
shielding walls along highways, building exterior shells designed to
insulate against noise for buildings located near noisy airports or
freeways, better walls and floor ceiling constructions between dwell-
ing units in multi-family dwellings, and--as a last resort — personal
hearing protection for the worker or recreationist in a high noise en-
vironment. )
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Each of these technical interventions carries with it the necess-
ity of an analogous legal requirement. For example, the achievement
of noise reduction at the source corresponds to numerical limitation
of source noise emission by regulation, performance standards limiting
by regulation the extent of the noise environment permitted by highways
and airports, the use of purchasing power and such other motivational
means as may be available to government agencies to encourage the
design and marketing of quieter noise sources, and the application of
consumer preference to motivate the same results. For intervention in
the propagation path, the corresponding legal/institutional approaches
include the requirement of a noise element in land use plans, the re-
quirement of a quantitative noise prediction in transportation system
design, the use of periormancc zoning in both cities and outdoor rec-
reational areas, the amendment of building codes to establish perfor-
mance requirements for noise insulation in buildings (especially dwell-
ings); and in the case of the employee work place situation, the im-
plementation of health-related protective laws, of which the Occupa-
tional Safety and Health Act (and similar hearing protection regulations
within governmental agencies) represent examples.
Much more could be said about the foregoing three-part logic model,
in such terms as comprehensive and systematic techniques of achieving
a given ambient design ;oal, and doing so at least total system cost.
However, the concept is presented here only for the purpose of providing
background to the subject of monitoring noise in the ambient environment.
PURPOSES OF MONITORING THE AMBIENT ENVIRONMENT FOR NOISE
Monitoring of the ambient environment for noise may be desirable
for a variety of reasons. No baseline measurement of the typical noise
environments in American cities, towns and open spaces presently exists;
such a general baseline should be established. A comprehensive monitor-
ing survey is a necessary first step whenever any city undertakes develop-
ment of a new noise abatement program; the drafting of a performance type
noise ordinance specifying a set of ambient limits is a desirable second
step. Special projects in baseline monitoring should be undertaken in
areas being considered ior the siting of new airports, new highways, or
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other major noise sources as necessary background information for the
assessment of environmental impact as a result of the proposed action.
Periodic mo litoring of the ambient onvironment ior noise should be
repeatrd in outlying areas where fixed permanent monitoring systems
, not be justifiable from a cost standpoint; the existence of such
monitoring in the past would have saved us fiom some recently discovered
surprises regarding aircraft noise ^t large distances irom airports, for
example (in both urban and wilderness areas) which otherwise have to be
brought to our attention by complaints of the. noise impacted citizenry.
Finally, continuous monitoring by fixed monitoring systems should be-
come the i ule rather than the exception, particularly for airports,
airbases, and highly urbanized areas where knowledge of the time trend
of the noise environment can be utilized as a decision-making tool for
controlling that environment.
AVAILABLE FOUNDATION FOR A NOISE MONITORING PROGRAM
In tie noise pollution field, the state-of-the-art of measurement
of the pollutant is well prepared for the job at hand. This is one
field where the state-of-the-art of measurement (and, indeed, of poten-
tial means for abatement as well) places us in a good position for an
action oriented program. The same cannot be said, however, for the
state of knowledge on noise effects; the completeness of our knowledge
of noise effects is well beyond the general layman's awareness, and yet
our ability to predict all the effects is considerably behind our
ability to measure the noise itself.
The development of the science of acoustics has been an outgrowth
of the sciences of physics and mathematics. Perhaps the most notable
early milestone in this development was the major treatise on the
theory of sound, written by Lord Rayleigh (in 1872, during his honey-
moon on a houseboat trip up the Nile River). A major impetus to the
field of noise and vibration as an applied science occurred during the
recent development of aviation and space act vities, as a result of the
need to protect people and vehicular structuies from the destructive
vibrations which could be induced by intense sound fields from jet and
rocket engines. Tolgive an iJea of the time scale involved, the
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Acoustical Society of America has been in existence for 40 years, the
first comprehensive survey of an ambient noise environment with reliable
instrumentation was made in 1937, and a major handbook for the use of
.^ineers and other workers in noise measurement and control, "The
Handbook of Noise Control" was published in 1957.
Much research has gone into the development of suitable scales for
measuring noise in ways that are related to the auditory characteristics
of human hearing, and to the subjective judgments of noise environments
made by people. Single-event scales have been developed to measure the
magnitude of a single noise event (such as the level of noise from a
single aircraft flyover or truck passby); and composite scales have
been developed for expressing the "noise climate" at a point in a
community, taking into account the total noise input from the suc-
cession of single events, the duration and frequency of intrusive noise
events, and the distribution of such events — during daytime or night-
time hours--around the 24 hour day. Examples of single event type
scales are the A-weighted sound level (in dbA) and the Perceived Noise
Level (in PNdB). Examples of multiple event (or composite) scales are
the Composite Noise Rating (CNR), the Noise Exposure Forecast (NEF),
and the Community Noise Equivalent Level (CNEL). Learning the char-
acteristics of scales for expressing noise, together with understanding
the circumstances under which each is appropriate, is the first task
which confronts the newcomer to the field of noise measurement and
control.
The development of acoustics as a science, and its more recent
expansion into the field of noise abatement, has been accompanied by
the development of a whole system for developing national and inter-
national standards for acoustical instrumentation, for the measure-
ment of sound, for measuring the performance of building elements in
terms of their noise insulating qualities, and many other special
measurements related to the noise abatement problem. Many professional
societies and other standards writing bodies have contributed to this
effort, notably, the Acoustical Society of America, the Society of
Automotive Engineers, and the American Society for Testing Materials.
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Institutional arrangements for adoption of acoustical standards include
the American National Standards Institute at the national level and the
International Organization for Standardization (ISO) and International
Electrotechnical Commission (IEC) internationally. A complete refer-
ence listing of such standards writing bodies and standards applicable
to various aspects oi the noise abatement problem will be available
in a forthcoming technical information document to be published by the
Office of Noise Abatement and Control, as one of a series of technical
information documents supplementing EPA's report to the President and
the Congress on noise.
Instrumentation presently available and in use for measuring the
ambient noise environment ranges all the way from the simple hand-held
sound level meter (which together with its microphone calibrator may
cost as little as approximately $500) to a complex, automated, multiple
microphone, fixed monitoring network for airports, intended to supply
both single event and multiple event information to the airport operator.
One example of such a system is the new monitoring system at Los Angeles
International Airport, designed and installed at a cost of approximately
$200,000.
Between these two extremes, there is a wide ran™e and variety of
standardized and commeri ially available equipment for measuring, re-
cording, analyzing and displaying the characteristics of noise environ-
ments. The recent interest in noise as an environmental pollutant,
together with the potential market this signifies to instrument manu-
facturers, has motivated them to begin applying solid state technology,
digital techniques, and automatic data analysis systems in many of the
recently designed instruments and systems. We can expect to see further
payoff in the future in terms of cost reduction, system simplification
allowing use by less highly trained personnel, and the availability of
more compact and portable equipment.
QUANTITATIVE DESCRIPTION OF A NOISE ENVIRONMENT
Nature of the Acoustic Signal
Suppose we take a simple system consisting of a transducer, an
amplifier, and some form of readout such as a level recorder. If we
place our microphone at a point in the community so that we can record
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the time history of the ambient noise environment we may expect to
see a rapidly time-varying trace such as that in Figure 3. Figure 3
was obtained from a level recorder trace of the A-weighted sound level
o-^er a period of minutes at a point in a typical suburban residential
community. The peaks of the spikes give the sound levels of the in-
dividual noise events, and the level to which the trace always recedes
is the "residual level," formed from the inflow of acoustic energy
from many distant sources.
If we were to make an audio recording of the same noise environ-
ment, we could then analyze the instantaneous signal at any point in
time into its spectrum. For example, Figure 4 shows the typical octave
band sound pressure levels we might expect to obtain from the measure-
ment of a passby of a truck or an automobile. Information about the
spectral distribution of acoustic energy is usually necessary for de-
sign purposes and for purposes of certifying that a particular product
meets a noise standard. However, it is not generally necessary (and
might be prohibitively expensive) for purposes of routine environmental
monitoring.
Referring again to Figure 3, if we were to continue the time
trace over a 24-hour period, we would see the results of a large
variety of noise producing activities, and the general would decrease
during a period at night as the activity level of the community de-
creases. The amount of this decrease and the time duration of what
we may call "night" in terms of quiet varies from one community to
another. The point to be made, however, is that a statistical analysis
of this time trace would tell us for what percentage of time the noise
level exceeds various values. Such a statistical distribution is one
way of showing the noise environment at a given point in a community.
Figure 5 shows an example of a cumulative statistical distribution in
one community, for the 4000 Hertz octave band only. It requires eight
such charts to show all the octave bands of interest, for a single
community point.
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Translation into a Composite Scale
By now, the reader may be experiencing some concern about the
number of parameters involved in quantifying a noise environment,
and realize the need for simplifying these parameters into a don-
^••.acd means of expressing the noisiness of a particular location.
One step in that simplification is available if the decision can be
taken to record the time history in terms of a single event scale
which has already applied a particular weighting to the spectrum and
therefore expresses the magnitude of each single event in terms of a
single number rather than a set of levels in each octave band or
third octave band. The A-weighted sound level is a major candidate
for such application because it performs well in correlating collections
of individual subjective noise judgments against the measured sound
levels, and because it is applicable to relatively low-cost monitoring
systems.
Even then, we are left with the necessity of expressing the noise
environment at the point in terms of a single number which accounts
for the time variations involved over the 24-hour period. Attempts
to do this in a way that is related to the community annoyance effects
of noise have led to a number of composite scales such as CNR, NEF,
etc. These composite scales generally take into account such factors
as the magnitude of the individual noise events, the number of such
events, and the percentage of the events which occur during the night-
time hours when most people want to sleep; some composite scales also
account for the duration of the individual events. We believe it is
also necessary to account for the existing residual (or background)
noise level in the community, and perhaps for such factors as any im-
pulsive noises (such as hammering or riveting) or of the presence of
any discrete tones such as caused by a power saw or by fan or com-
pressor noise from an aircraft engine. Although a number of composite
scales exist, most of them have been developed to deal with aircraft
noise only or traffic noise only, and we are left with the urgent
problem of developing a valid universal scale for community noise
from all sources which is related in a tested way to the annoyance
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response ol communities of people experiencing chat noise environment,
in terms of the opinions they express in a social survey.
Once a composite noise scale is adopted, the noise environment at
• ^rious points in the community (as based on the total experience over
any given time period such as a day, a week, or a year) can be quanti-
fied, and as a result it is also possible to draw "noise contours".
These contours are lines of equal "noisiness" in terms of the selected
composite scale, just as contour lines on a topographic map are lines
of equal elevation. They can be used to delineate varying degrees of
noise exposure on a map, as shown in Figure 6 for a .hypothetical
airport.
The state-of-the-art in noise prediction is adequate to allow the
estimation of sets of noise contours associated with such transpor-
tation elements as planned airports, freeways and highways, given as
input data the anticipated types, numbers and paths of vehicles in-
volved. The use of quantified noise contour predictions should become
a routine part of the process of transportation system planning and
design, urban land use planning and design, and the environmental
impact statement process as required under the National Environmental
Policy Act. Predicted noise contour sets are a crucial tool in the
decision making processes associated with the siting and routing of
transportation system elements, the appropriate zoning of land uses
surrounding airports and adjacent to highways, and the establishment
of special building code districts dovetailed into those noise zones.
While noise contours can be predicted adequately for planning
purposes, there is no substitute for measurement when one is dealing
with a real airport or an existing community, coupled with the vagaries
of varying atmospheric conditions, non-ideal flight paths of air
vehicles and variable operating modes of surface vehicles. The appli-
cation of a suitable metric (composite scale) to both the prediction
of noise contours and their measurement can provide an invaluable
two-pronged tool to control the noise environment.
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TYPICAL NO I SK MF.ASUREM!' NT SYSTEMS
Sound Level Meter;
The simplest device for measuring a noise environment is the
•i 'r.^ie hand-held sound level meter. Figure 7 shows two examples of
commercially available sound level meters, capable of providing direct
reading meter measurements of A-wei^hted, B-weighted, or C-weighted
sound levels. Figure 8 shows the amount of emphasis given to each
part of the audible spectrum by these three standard weighting circuits,
together with that given by a D weighting circuit presently under con-
sideration for inclusion in a measurement standard. The A weighting
is the most useful, since it approximates the frequency response of
the human ear and it has been found to give results that correlate
best with individual subjective judgements of noise. The C weighting
is useful to have on a sound level meter since it gives a close
approximation to the level that would be read with equal emphasis
across the spectrum. The effect of applying the A weighting is illus-
trated in Figure 9, where the actual (unweighted) spectrum of a sample
of outdoor residual noise is compared with the spectrum shape that
results from applying the A weighting. The performance requirements
for the various types of sound level meters, microphones, etc. are
prescribed in nationally adopted acoustical standards published by
the American National Standards Institute.
Record-and-Anaiyze Systems
For many purposes it may be desirable to obtain a recording of the
noise environment. Such a recording may be played back later as a
demonstration of that environment for people involved in the decision
making process but who have never experienced the noise environment
in question, may be stored for later analysis in the laboratory, and
may be subjected to all of the detailed analysis into statistical
characteristics and spectral characteristics as outlined above.
Figure 10 shows a typical field outfit for obtaining scientific pre-
cision audio recordings. It is desirable to have a tape recorder with
two channels, since some types of recordings require two simultaneous
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microphones, and others benefit from having one channel free for a
voice narrative by the field investigator. Tape recorders for field
use ideally should have a playback capability built in, as it is
r<~~ssuring to be able to confirm that one has a valid recording
before leaving the site.
A variety of analysis and readout alternatives are available when
one has the noise history available on an audio recording. For example,
Figure 11 shows, in diagram form, the basic equipment for recording and
subsequent statistical analysis. When statistical analysis is not
necessary, spectral analysis may be desirable, or even a simple level
recorder trace as output may be useful for visual display purposes.
Real Time Analysis
For an extensive survey, and particularly when statistical analysis
is required, the amount of data can rapidly become excessive in terms
of the laboratory analysis time unless real-time analysis is used.
The term real-time implies that data processing and display occur almost
simultaneously with data input, so that decisions regarding the nature
of the input may be made immediately. Figure 12 shows the basic equip-
ment required for real time analysis, with both frequency analysis and
statistical analysis outputs shown.
Automatic Monitoring Systems
The need to control the noise environment of airports has given
rise to the design and installation of a number of airport monitoring
systems. These systems range from simple single event monitors such
as those at Kennedy Airport (which measures the Perceived Noise Level
of each flight) to the more sophisticated systems which are capable of
measuring not only single events but also the "noise climate" (in terms
of some composite scale) as experienced at a number of points around
the airport. Some of these airport monitoring systems have already
proven their usefulness in controlling and reducing airport noise and
in providing assurance to those attempting to plan for land use around
the airport.
The list of airports in the world which have instituted noise
monitoring is a fairly large and rapidly growing one. It presently
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includes at least the following airports (and even this list may not
be complete):
Airports with Noise Monitoring Systems
Amsterdam (Schiphol)
Frankfurt/Main
Stuttgart
Zurich (Kloten)
Paris (Orly)
Osaka
Oslo (Fornebu)
Kennedy, Newark, LaGuardia
Orange County Airport (California)
Other cities which presently have gone out for bids on noise
monitoring systems for their airports include Rio de Janeiro, Melbourne
(Australia), London (Heathrow) and Tel Aviv. As of this writing there
is indication of strong interest by the Boston Port Authority in acqui-
ring a noise monitoring system for Logan Airport, and Los Angeles Inter-
national Airport's new monitoring system is scheduled to go into operation
in December of this year.
The state of California has recently adopted a statewide airport
noise regulation, which requires noise monitoring for "noise problem"
airports, and sets forth the system specifications for such monitoring
systems within the regulation. Figure 13 shows the system diagram for
the measurement of a quantity called "hourly noise level," which is a
basic ingredient of the calculation of "community noise equivalent
level" (CNEL), a composite measure of the "noise climate". The regu-
lation also calls for single-event monitoring. The airport monitoring
system voluntarily adopted by Orange County Airport in California was
influenced in its design by this airport noise regulation, and the
airport monitoring system for Los Angeles International Airport is
designed specifically to meet the requirements of the California
regulation.
Among the existing airport noise monitoring systems, that at
Stuttgart is particularly of interest, partly because the measured
noise environment is, in fact, being supplemented by a program of land
use control by the government, a necessary complement to the control
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of the "noise footprint" generated by the airport. Figure 14 shows
a layout of the monitoring points around Stuttgart Airport together
with a photograph of the central station equipment.
Several airports were noted above which are currently out for
Dids for new noise monitoring systems. The systems prescribed by
these airport authorities have several qualities in common: They all
require a number of remote microphone positions, varying from 12 to
16 per airport, with the microphones placed on telephone poles, the
measurements made in A-weighted sound level, these Levels converted
to frequencies proportional to level and then transmitted back to a
central station by means of narrow band telephone lines. At that point
the systems diverge in their requirements according to the individual
needs of the airport. In some cases, only individual events producing
levels which exceed a predetermined level are identified. In some,
the "noise climate" at each microphone position is computed in terms
of some composite scale, usually the noise exposure index Leq, obtained
from an integration of the A-weighted sound level from all events, with
suitable weighting factors applied to those events which occur at night.
Most of the systems involve a small computer which also includes
the flight plan information, and thereby identifies the specific
flights which cause preset noise levels to be exceeded. Again, the
details of storage and display vary from one airport to another. It
is common to have an initial survey done using portable equipment to
establish the initial noise contours of the airport environment, and
then utilize the fixed monitoring system to prevent the contours from
spreading farther. The actual prevention is achieved by the airport
proprietor applying his legal prerogatives in allowing or disallowing
particular aircraft, pilots or airlines to continue to utilize his
airport or to do so under certain specified conditions of takeoff
weight, runx^ay utilization, and hours of operation, or such other
regulations of the airport as may be necessary to control the noise
environment. Even as an information gathering tool, quite aside from
any regulatory authority, noise monitoring systems at airports have
proven themselves to be extremely effective in curbing the unnecessary
or preventable portion of noise associated with airport operations.
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In at least one instance, an attempt has been made to apply
computer mapping to illustrate the measured noise environment of a
portion of a city. Numerous other cities (in other countries) have,
of course, performed comprehensive noise mapping surveys using field
-earns. Figure 15 shows a computer plotted noise map of the measured
noise environment of the Mount Royal Plateau, for seven categories of
intensity, performed by the city of Montreal as part of its compre-
hensive noise abatement program. In this instance, the data was
obtained by measurements using a portable van, and the computer
mapping achieved by off-line treatment of the data. However, this
result, coupled with the state-of-the-art in airport noise monitoring,
gives promise of the feasibility of automated systems which can
measure the noise environment and produce a display of that environ-
ment in terms of computer-plotted noise maps.
CONCLUSION
A brief introductory survey has been given of the state-of-the-
art in noise monitoring. Selected references for additional study
are given in the attached list.
In closing, we should like to emphasize several major points.
First, the available technology for measuring noise is ready to
support a national noise abatement program. The activities of this
country generally lag behind those of other modern industrialized
countries in applying this technology.
Second, a key element in the design of automatic monitoring
systems applicable to community noise is the development of a univer-
sal scale for community noise, simple enough for minimum cost noise
monitoring systems, and validated against the subjective judgements of
people living with those community noise environments.
Third, there is a broad range of equipment and instrument tech-
nology available to apply to the monitoring of ambient noise environ-
ments, from the simple hand-held sound level meter to complex, auto-
matic noise monitoring networks. A maximum effectiveness, minimum
cost approach to a national noise abatement program will probably
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require some utilization of both those extremes. For example,
maximum I Icxibil ity is provided by teams in the field with portable
equipment. Recent KL'A-funded experiments at Federal City College
C1' .shLngton, D. C.) have shown that relatively untrained personnel
can be trained to make valid noise measurements with simple, com-
mercially available equipment. Long term monitoring of community
and airport environments will require the more sophisticated auto-
matic monitoring systems, which afford the most useful information
for testing abatement strategies, and for documenting the long term
trend in noise environments.
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SELECTED REFERENCES
1. C. M. Harris, Ed., "Handbook of Noise Control", McGraw-
Hill , 1957
2. L. L. Beranek, "Acoustic Measurements", John Wiloy & Sons,
New York, 1949
3. A. P. G. Peterson and E. E. Gross, Jr., "Handbook of Noise
Measurement", 6th ed., General Radio Company, West Concord,
Massachusetts, 1967
4. "Acoustics Handbook", Application Note 100, Hewlett-Packard
Company, 1501 Page Mill Road, Palo Alto, California,
Nov 1968
5. "Examples of Application" B&K Instruments, Inc. 5111 West
164th Street, Cleveland, Ohio, 1971
6. "Standards, Formulae and Charts: Excerpts from International
Standardization and Acoustical on Mechanical Measurements",
B&K Instruments, Inc., 5111 West 164th Street, Cleveland,
Ohio 1971
7. An information document on the fundamentals of noise, written
by the National ilureau of Standards under contract to EPA,
to be published
8. "Noise Programs of Professional/Industrial Organizations,
Universities and Colleges", EPA NTID300.9, to be published
9. American National Standards for Acoustics, Vibration,
Mechanical Shock and Sound Recording, American National
Standards Institute, Inc., 1430 Broadway, New York City
10. "Supporting Information for the Adopted Noise Regulations for
California Airports", Wyle Laboratories WCR 70-3 (R),
Jan. 29, 1971
11. F. C. Petts, "Practical Noise Control at Incernational Airports,
with Special Reference to Heathrow," Journ. Royal Aero. Soc.
70, 672, 1051-1059, Dec. 1966
12. "An Assessment of Noise Concern in Other Nations", EPA NTID
300.6, to be published
II - 94
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APPROACHES TO WATER QUALITY MONITORING
William T. Sayers
Office of Research and Monitoring
Environmental Protection Agency
INTRODUCTION
Water quality monitoring has been practiced on a more or less
routine basis since the latter part of the 19th century. In the early
days attention was directed almost solely toward bacterial pollution.
Health authorities at that time mounted a massive Federal and State
effort to combat water borne diseases, such as typhoid fever, which
were prevalent then and into the early part of this century.
Since that time, attention has broadened to include many other
measurements that have become necessary in order to fully characterize
water quality and changes in it. Increased economic activity over the
past 100 years has resulted in the introduction to our Nation's waters
of many new polluting inibstances and increased amounts of many of the
old polluting substances. There are presently an estimated two million
known chemical compounds. Several thousand new chemicals are discovered
each year. Most of them eventually find their way into the Nation's
waters. This fact plus recognition that there are continual chemical
and biochemical changes occurring in the receiving waters indicate to
us that the water quality indices deemed to be of general interest may
well continue to increase with time.
II - 110
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As the population and economic activity expand, water use and
waste production will continue to increase. In another 10 years or so
water use for municipal supplies, manufacturing, and irrigation will
approach 650 billion gallons per day, which is equal to the total estimated
dependable fresh water supply of the United States. These facts clearly
indicate that water will have to be reused on a larger and larger scale
in the future. To accomplish this, water quality will have to be
effectively controlled through coordinated local-State-Federal water
resource management programs.
Water resource management, in its highest sense, implies the
systematic control and manipulation of all variables affecting water
quality and quantity so as to maintain conditions that will yield the
greatest over-all benefits. Effective water resource management requires
the use of reliable and timely information on water quality. Thus, the
key to effective water resource management is the ability and capability
to monitor substances (and understand their behavior) in water. In
addition, water quality monitoring serves as the best "yardstick" for
evaluating the effectiveness of a water resource management program.
BASIC OBJECTIVES OF WATER QUALITY MONITORING
Water quality monitoring should be carried out with specific
objectives clearly in mind. Basic monitoring objectives include:
1. The establishment of baseline water quality and identification
of short- or long-term trends;
II - 111
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2. Evaluation of compliance or noncompliance with water quality
standards;
3. Development of mathematical models for forecasting water
quality under a variety of waste loadings and hydrological
conditions; and
4. Obtaining data for input to existing models used in the day-
to-day management of a water resource.
Monitoring carried out for the purpose of establishing baseline
water quality and making trend evaluations will generally also serve to
detect the emergence of adverse conditions before actual water quality
standard violations occur. This permits action to be taken early to
prevent a standards violation rather than later when the costs are
greater. Thus, monitoring makes it possible for the water quality
manager to spend his limited resources on "ounces of prevention" before
damages occur rather than on "pounds of cure" after the damage is done.
This is the essence of a true water quality management program.
Maintaining compliance with water quality standards will require
not only the existence of adequate waste treatment and control facilities
but also the operation of these facilities day after day at or above
design efficiency. A monitoring program sufficient to detect serious
temporary standards violations will serve to discourage intentional
waste bypassing or shoddy operation of the treatment and control
facilities. Such a monitoring program is essential in achieving full
implementation of the State-Federal standards developed over the past
several years.
II - 112
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The huge expenditure required for waste treatment facilities
across the nation in order to achieve and maintain compliance with
water quality standards and the limited funds available for this
endeavor demand that the funds be utilized in the most cost-effective
manner. Accordingly, wastewater management planning efforts must be
sufficient to identify maximum permissible waste loads and specific
treatment requirements in successive reaches along each water course.
Plans must also identify where joint treatment of wastes from several
communities is less costly than individual treatment by each community.
These plans must identify not only current treatment needs but more
importantly, the treatment requirements of each community or region
at various dates in the future. This information will serve to ensure
that all treatment facilities are constructed and in operation by the
time they are needed.
Preparation of these water quality management plans requires the
development and use of mathematical models relating waste discharge
loadings to water quality in the receiving body of water. The develop-
ment of a mathematical model, in turn, requires sufficient monitoring to
completely characterize water quality in the receiving body under a
steady-state waste loading and hydrological condition.
In areas of dense population, complex waste sources, intensive
water use, and close hydrologic interrelationships, mathematical models
may well be used by basin managers to identify day-to-day adjustments
needed in reservoir releases, storage and releases of treated effluents,
II - 113
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waste treatment operating efficiencies, and other control measures in
order to maintain optimal water quality conditions. Such a management
system will require continuous monitoring at key points in the basin
in order to provide the necessary model input data.
MONITORING PROGRAM DESIGN CONSIDERATIONS
In the design of a monitoring program, the specific objectives to
be served must be clearly in mind from the very beginning. Otherwise,
the effort will probably not result in an efficient and meaningful
program. The length of the survey, station selection, parameter coverage,
and sampling frequency all depend on the specific objectives and the time-
frame in which the objectives must be achieved. These variables also
have a very significant impact on monitoring costs.
Monitoring for the purpose of establishing baseline water quality
can generally be accomplished by intensive sampling over a one to two
week period during each season of interest. If results are not needed
for several years and the quality is not expected to change significantly
during that period (e.g., in a wild river), then objectives can also be
met by sampling at rather infrequent intervals over the entire period.
Monitoring for the purpose of mathematical model development
requires intensive sampling of the waste sources and the receiving waters
over a short time period. In that steady-state conditions are assumed
to exist during a given sampling phase, it must be short enough so that
variations in waste discharges and stream flow are minimal throughout
the period.
II - 114
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Monitoring for the purpose of long-term trend identification,
evaluation of standards compliance, or river basin management must,
of course, be a continuing program without end.
The number and spacing of monitoring stations also vary considerably,
depending on the objectives to be achieved. Baseline water quality
evaluation can be achieved with a minimal number of stations providing
sparse coverage of a vast area. Mathematical model development, on the
other hand, requires a relatively large number of stations giving complete
coverage of a small area.
The parameter coverage provided, likewise, varies with objectives.
Baseline water quality and trend evaluations require measurement of all
indices that are likely to be of interest in the future. Model develop-
ment, conversely, requires evaluation of only those parameters being
modeled plus the independent variables that influence the parameters
of interest.
The sampling frequency necessary to characterize a body of water
is related to the periods of cyclic phenomena which control quality and
to random influence, mostly associated with meteorologic and hydrologic
events. The number of time-dependent factors which must be considered
depends on the type of water body in question, the wastes being discharged,
and the particular parameter of interest. Generally, temporal variations
in water quality are least frequent in large impoundments and most
frequent in rivers.
II - 115
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The actual number of samples required over a given time period
at each station to characterize water quality, in essence, depends on
the variability of the parameters of interest, regardless of the number
and kinds of influencing factors. In a statistical sense, there is no
answer to the question of how many samples are needed, without fore-
knowledge of the variability of the parameter to be sampled and the
precision desired. It can only be said that enough samples should be
collected to define, at a specific level of significance, the water
quality response caused by the imposed influencing factors (e.g.,
pollutant load, manipulation of stream flow, tidal conditions, and
sunlight). The adequacy of the number of samples taken in a given
period can be judged by the magnitude of the 95 percent confidence
interval.
Often, too many stations are established with an insufficient
number of samples collected at any one. A fewer number of stations
with a sufficient number of samples to define results in terms of
statistical significance is much more reliable than many stations with
only a few samples at each. Sampling (for the purpose of describing
a given condition) should not be spread over a long time interval during
which the receiving water regimen is subject to a wide variety of
conditions. Attempts to assess all conditions by an aimless sampling
program usually defines no condition and, in fact, may be very misleading.
Averaging of such noncomparable results is often a risky procedure.
Instead, the sampling program should be designed so that each condition
II - 116
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o ' interest is defined rather than attempting to define all the conditions
( -esulting from hydrologic, hydraulic, or hydrodynamic variations) by
m srely "averaging" then, together.
Another factor which influences the number of samples required
ii a given time period is the precision of the test for the given para-
ir 3ter being measured. If, for instance, mean temperature and coliform
d msity (MPN) were to be evaluated under steady-state conditions at
s Dme point in a small well-mixed stream, a greater number of coliform
E amples (minimum of about 16) than temperature samples (minimum of
cbout 3) would be required for an equal degree of reliability in the
issults. This is because the MPN test procedure is subject to a much
*ider variation than the temperature test. Hence, when several para-
nsters are being measured at a given site, the number of samples
c ollected should be sufficient to satisfactorily evaluate that para-
reter tested by the least precise method.
Given a large number of samples collected at short time intervals,
1 he results obtained can be analyzed to determine the optimum frequency
J or meeting a given set of objectives. Within the realm of practicability,
1 owever, this is seldom possible. Judgement must be used in arriving at
< first approximation of the optimum frequency. Where the objective is
• o determine trends in water quality on a wild river, a sampling frequency
- hat will require several years in order to accumulate sufficient data
- o make an evaluation may be satisfactory. On the other hand, where the
( bjective is to spot violations of standards in waters of marginal
II, - 117
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quality, a much greater frequency would be required—one that permits
the accumulation of sufficient data to draw conclusions in a matter of
hours or days, depending on the value of the resource affected.
Evaluations to be made with the water quality data collected are
generally not possible without some additional data on hydrological,
hydrographic, and meteorological conditions during the period of the
monitoring survey. If, for example, the evaluation is of a stream,
information is needed on the stream discharge rate during the sampling
period and the historical flows.
When the objective includes development of mathematical models
for establishing cause-effect relationships, information on times-of-
flow at a range of stream discharge rates is essential. This requires
the measurement of velocities along a stream at a minimum of three
different stream discharge rates. Dye tracers lend themselves very
well to studies of this type. If reaeration rates (using the O'Connor-
Dobbins formula) are to be included in a mathematical model, then
stream depths must also be measured for a range of discharge rates.
For most free-flowing streams, a plot on log-log paper of stream
discharge rate versus velocity and depth will result in straight lines,
thus permitting interpolation between actual measurements.
Studies of open waters (e.g., large impoundments, lakes, estuaries,
and coastal waters) often require that several meteorological measurements
be made. These include wind speed and direction, air temperature and
humidity, solar radiation intensity, and tidal cycles. The meteorological
II - 118
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p; rameters actually evaluated depend on the relationships that are to
bi established. If it is mixing and/or flow patterns, then wind speed
ai d direction would be important; if it is the dissipation of heat
r< suiting from a source of thermal pollution, then air temperature and
hi midity, in addition to wind speed, would be of interest.
WJ TER QUALITY MONITORING TECHNIQUES
Earliest water quality monitoring techniques employed the collection
o: grab samples using a bucket suspended from a rope with sample
ai alysis carried out manually on the stream bank or in a nearby
1; boratory. This approach is still in wide use today. The reason for
ii s continued use is not so much due to its outstanding advantages as
H is to the fact that there is no alternative technique available for
a< hieving the same objectives.
Early attempts to improve on the state-of-the-art of water quality
m< nitoring centered largely around automation of the sample collection
aj d laboratory analysis phases. There are numerous automatic sample
ctllection devices on the market that can be timed to obtain discrete
g]ab samples at predetermined intervals and to even composite the
Scmples in proportion to wastewater flow rates. At the end of the
simpling period, the station must be visited, the sample or samples
p: eked up and then hand carried to the laboratory for analysis. These
s< mplers are designed primarily for use on effluent lines rather than
it open waters, however.
II - 119
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Many of the laboratory analyses that were formerly carried out
manually have now been automated. Newer laboratory instrument designs
have incorporated automatic sample handling, sequential analysis, and
improved data presentation. Many instruments are capable of withdrawing
an aliquot of sample, performing the measurement, and presenting the
data as concentration of the constituent, in printed form. Connection
of analytical instruments directly to a computer to eliminate all manual
operation from sample aliquot withdrawal to final data storage is
possible in some situations. This approach /Jill very likely be employed
to a greater and greater degree in the futuro.
»
Some of the newer instruments found in routine use today in many
laboratories include:
Automatic Titrators Gas Chromatographs
Technican Autoanalyzers Atomic Absorption Spectrophotometers
Total Carbon Analyzers Infrared Spectrophotometers
Specific Ion Meters
EPA and its predecessor agencies concerned with water analysis
have long recognized the need for automatic field instrumentation
capable of giving a direct and instantaneous read-out of the levels of
specific water quality indices. Work was be/un in 1953 by the former
U. S. Public Health Service Division of Watej Supply and Pollution in
cooperation with the Hays Corporation on the development of such a
device for the continuous measurement of dissolved oxygen. Other work
of a similar nature soon followed. Efforts centered on the development
II - 120
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cf sensing devices utilizing a direct electrical response mechanism.
"his work led to the preparation in November 1962 by Mr. A. F. Mentink
cf the first set of Public Health Service specifications for an integrated
r alti-parameter water quality data acquisiti m sys%em. Mr. Mentink of
1 he Analytical Quality Control Laboratory ir Cincinnati is now engaged
:n the preparation of the ninth edition of tlese specifications.
Of those parameters of general interest in water quality surveys,
•f o date, eight of them can be reliably measured by continuously operated
electronic sensors placed in the field. These are pH, temperature,
cissolved oxygen, specific conductivity, chloride, turbidity, oxidation-
isduction potential, and solar radiation int msity. Results can be
iscorded on site or telemeter 3d to a central location.
Many portable single parameter electronic sensors are also
fresently on the market. They are of considerable value in the conduct
cf short-term intensive surveys and for reconnaissance purposes.
Another rather recent monitoriog technique that may eventually
h ave significant application in the evaluatic n of water quality is remote
cf spectral sensing from aircraft or satellile. It has the potential
to provide rapid overall assessment of pertirent river basin characteristics,
sich as population distribution, land and wai er uses, and location of
vi iste sources, as well as to provide informal ion on the physical, chemical,
biological, and hy Irographic characteristics of surface waters.
Spectral sensing in the Infrared range is particularly useful
ii measuring variations in weter surface temperature over wide areas.
I: - 121
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Natural color photography is also quite useful in that it provides a true
"bird's eye view" of large water areas and permits a rapid qualitative
evaluation of visible pollution problems. Locations where quantitative
evaluations would be most meaningful are thus immediately identified.
Although the application of remote sensing technology to water
resource management has really just gotten under way, the present
state-of-the-art is already rather impressive. Remote sensing is expected
to play an increasing role in future water quality management programs.
AUTOMATED VS. MANUAL MONITORING TECHNIQUES
Electronic monitors and aerial remote sensing techniques
significantly increase our technical capability to monitor surface
waters on a continuous or near-continuous basis. However, they are
not a panacea.
In terms of evaluating compliance with water quality standards,
only one parameter of interest, temperature, can presently be measured
quantitatively using remote or spectral sensing techniques. Electronic
sensors provide a little more versatility in that they are capable
of measuring six parameters likely to be found listed in water quality
standards. This leaves 50 or so parameters contained in or alluded to
by the standards for which no alternative for evaluation other than
manual sample collection and separate laboratory analysis exists.
For those parameters where there is a choice between manual
and automated monitoring techniques, the decision on which approach
to pursue should be based on economic considerations. Once the number
II - 122
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and location of stations, the parameter coverage, and the minimum
necessary sampling frequency have all been identified, the cost of
each alternative approach can then be determined. The least costly
alternative should, of course, be the one implemented.
When comparing the flexibility and relative costs of manual
sampling and analysis versus electronic monitoring, the following points
should be considered:
1. Electronic monitors do not completely replace field personnel.
Each monitoring site should be visited at least weekly for
routine maintenance and recalibration. Equipment malfunctions
may require more frequent visitations. Higher salaried
personnel may be required for monitor maintenance than for
manual sample collection.
2. Automated monitoring system data handling costs will vary,
depending on whether analog or digital output is used. In
either case costs will generally be greater than if manual
techniques were used. The type of output selected depends
on the evaluation procedure and ultimate use of the data
which must be fully considered in the design phase of the
sampling program.
Generally the most important single factor in determining
whether manual or automated techniques should be used is the monitoring
frequency that is required. In the manual approach, monitoring costs
vary almost directly wi^h measurement frequency. At monitoring frequencies
II - 123
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much greater than once per week, automated sonsing will generally prove
to be the more economical approach, provided that appropriate sensors
exist.
MONITORING INSTRUMENTATION NEEDS
As water is reused to a greater and greater degree in the future,
more sophisticated water resource management programs will be necessary.
To function, they must have the capability to acquire timely information
on water quality over vast areas on a day-to-day basis. This capability
does not exist today. To achieve this capability, further research
and development are needed on:
1. Low cost automated (portable and fixed) water quality
sensors that can measure a wide variety of indices over long
periods with minimal maintenance.
2. Aerial remote sensing techniques for broad-scale evaluation
of water quality conditions over vast geographical areas.
3. New, more inclusive water quality indices that can better
lend themselves to automated and remote sensing techniques.
Instead of describing water quality changes using indices
such as dissolved oxygen, BOD, etc., perhaps consideration
should be given to the use of indices indicative of changes
in emission or reflectance of certain energy spectra from a
given water body. As long as the changes in emission or
reflectance were a result of changes in water quality conditions
and were generally proportional to the overall water quality
II - 124
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changes, this would be a useful approach. In fact, this
may be all the monitoring needed after 19&5 to enforce water
quality standards on navigable waters, if Senate Bill 2770
is passed as written. The bill proposes that the discharge
of pollutants into navigable waters be eliminated by 19&5.
SUMMARY
In summary, much of the water quality monitoring as carried out
toda;' is not drastically different from the ways in which it was con-
duct) d at the beginning of this century. Most of the improvements in
metto dology made over the past 50 years have been in laboratory as
oppo: ed to field techniques. The development of automated electronic
sens< rs for the measurement of a few parameters has, nevertheless,
provi n to be a significant step toward meeting the field needs of
tomo: TOW. Recent developments in remote sensing also offer much
prom: se.
One point is certain; if we want to begin thinking of ourselves as
true water quality managers we must act to prevent water quality problems,
not i ierely react to water quality problems that have been permitted to
occu: •. Prevention of water quality problems requires early detection
of ei lerging adversities, and early detection is not possible without
adeq .ate monitoring tools and a fully implemented monitoring program.
Effo- 'ts are presently under way to provide the necessary tools and an
adeqi .ate monitoring program. These efforts must be intensified, however,
if w< are going to make the transition from the reaction to the action
phas< by the time the present backlog of pollution problems has been
corr< cted.
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IN-SITU AND REMOTE SENSING FOR SOLID WASTES
Harry Stierli
Solid Waste Research Division
National Environmental Research Center
Environmental Protection Agency
Cincinnati, Ohio
INTRODUCTION
The purpose of this paper is to provide information on the
state of the art and current techniques for monitoring of pollutants
caused by solid wastes. Although at this Workshop we are concerned
primarily with sensors for monitoring environmental pollution, some
background and related material will be presented in explanation of
solid waste management problems and those parameters indicated for
detection, measurement and analysis.
All of us should be aware that storing, collecting, trans-
porting, processing and disposing of solid wastes can cause pollution
to our environment. For example, dumps and landfills are potential
sources of gaseous and liquid effluents for contamination of the
surrounding air, land and water. Likewise, incinerators, recycling
plants and other solid waste processing facilities may discharge
toxic or otherwise objectionable meterials to the atmosphere,
streams and land.
Pollution from solid waste differs from air and water pollution
in that it tends to be more of a local problem. Air and water carry
pollutants across political boundaries in response to natural laws.
In contrast, solid wastes are left where they are generated or are
2
transported mechanically. The solid wastes in a landfill remain
stationary and tend to retain their physical and chemical character-
istics. Decomposition of the material is relatively slow, and the
products of decomposition are localized and concentrated. The major
pollution effects are caused indirectly by decomposition products
3
rather than the wastes themselves. For example, the leaching of
breakdown products and soluble materials from buried wastes may
escape and contaminate ground and/or surface waters. Likewise, stack
II - 126
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d~" aarges from an incinerator may discharge particulate matter and
noxious gases into the atmosphere. These effluents from landfills
and incinerators also may contain toxic materials such as lead, cad-
mium, zinc, mercury, selenium, pesticides and polychlorinated biphenyls
(PCD). Although their presence usually is in small amounts, they can
have a significant public health effect. With pollution caused by
solid wastes being primarily from gases, liquids and particulates that
enter the air and water for transport, the sensing techniques are the
same or similar to those used in the air and water programs. However,
airborne remote sensing techniques such as multispectral aerial photo-
graphy and aerial thermal mapping may prove useful for landfill site
-, , . 20
evaluation.
At the Environmental Protection Agency's National Environmental
Research Center, Cincinnati, scientists and engineers are working
toward improved techniques for monitoring pollution and solving
environmental problems. And we have noted how pollution of one media,
land in the case of solid waste, leads to pollution of other media,
at- I've already mentioned. We see the n^ecl, and we hope everyone
sees tb° need of considering the total environment when dealing with
a particular problem.
SOLID WASTE INFORMATION N1.EDS
A variety of inforration is needed to manage solid wastes for
economic, aesthetic and environmental reasons. Table I lists some
of th^ types of data needed for purposes of administration and manage-
ment, research and scientific knowledge, and pollution surveillance.
Solid waste management re^uj—__ information c.~ waste quantities and
characteristics, practices, cost and performance of systems, manpower,
effects of solid wastes on the environment, legislative regulations
and related data. The 1968 National Survey of Community Solid Waste
Practices provides a baseline for some of the administrative and
management data needs.
II - 12?
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A systems analysis study of the container-train method of solid
waste collection and disposal is being conducted by the City of
Wichita Falls, Texas, under a demonstration grant supported by the
Environmental Protection Agency. In this study a municipal solid
waste data system is being developed to collect operational information
on a specific solid waste system. Solid waste weight data from both
fixed containers and container trains is collected in the field and
transmitted to the city's data processing center by means of a trans-
mitter located in a compactor truck equipped with front end loader.
The loader is instrumented with strain gauges which are calibrated
to provide accurate weight of each load lifted.
Physical and chemical parameters and methods for solid waste
characterization have been listed in a research report. The
following eight parameters were selected for special evaluation:
biochemical oxygen demand of incinerator quench water, carbon,
hydrogen, nitrogen, moisture, ash, volatiles, and calorific value.
Research reports on the methods of analysis of these parameters are
available for selected distribution.
It was necessary to modify a macroanalytical technique for
accurate analysis of carbon in the solid wastes sampled prior to
7
incineration and the residues following the incineration process.
This method provides both carbon and hydrogen content of samples
employing a dry combustion-purification-gravimetric approach.
Figure 1 shows the carbon-hydrogen train with the essential accessories
in a laboratory. This method can accurately analyze 1- to 10— gram
samples with carbon contents ranging from 0.46 to #3.31% an(3 with
hydrogen contents from 0.01 to T.SCffo.
For convenience, research and pollution surveillance monitoring
needs will be discussed in the following sections in relation to the
methods by which the solid wastes are processed or disposed.
II - 128
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JKv AERATOR EVALUATIONS
A number of municipal solid waste incinerators have been
tested and evaluated by the Solid Waste Management Program of the
rt
Environmental Protection Agency. Data were gathered on (l) the
quality and quantity of solid waste processed, residue and gasborne
particulate emissions, (2) the quality of the fly ash collected and
the wastewater produced, and (3) the economics involved in incineration.
Some of the information from these tests and related studies will be
presented to illustrate special methods and parameters of interest
concerning the characterizatior; of wastes, evaluation of performance,
and measurement of pollutants.
Standard stack sampling methods were used for measuring parti-
Q
culates and gases emitted from the incinerator stacks. The effluent
gases were sampled and analyzed for moisture, carbon dioxide, carbon
monoxide and oxygen. Particulate emissions were in excess of all but
the most lenient air pollution emission standards.
Process waters used in cooling and scrubbing emission gases
and parbiculates, and in quenching the a^h residue were sampled to
determine pertinent physical and chemical characteristics. The major
sources sampled were the incoming water, scrubber water, residue quench
water and plant effluent. Temperature and pH of all samples were
measured immediately aftr^- collection. After the samples were returned
to the laboratory, they were analyzed for alkalinity, chlorides, hard-
ness, sulfates, phosphates; conductivity and solids. The process
waters were coaT,arninated, and although several plants have primary
treatment facilities, furone- Lreatment should be required before
being discharged into the environment.
Microbiological sampling techniques and analytical procedures
have been developed for incineration testing. Samples of solid
waste and its residue after incineration were taken from eight incin-
erators .
-------
A sampler was designed and used to measure microbial cell
concentrations in incinerator stack emissions. Samples taken from
the stack of a conical burner showed that a few viable gram-positive
bacilli were emitted, but most of the organisms were scrubbed out.
Quantitative studies were made on the microbial flora of dust
from six municipal incinerators using an Anderson sampler. The incin-
erator dust was found to carry pathogenic microorganisms, such as
Staphylococcus aureus, Diplococcus pneumoniae, and Klebsiella pneumoniae,
although these represented a small percentage of the total number of
organisms. These organisms are associated with skin and the upper
respiratory tract ailments. Escherichia coli was found in the dust
at five incinerators tested, indicating the presence of fecal wastes.
LANDFILL EVALUATIONS
The principal means of disposing municipal solid wastes in the
United States will continue for many years to be landfills. For
purpose of this paper landfills include objectionable dumps as well
as sanitary landfills. When wastes are buried in a landfill, the
material decomposes by a combination of biological, chemical and
12
physical processes. Although the first stages of decomposition may
be under partially aerobic conditions, succeeding stages are primarily
anerobic in nature.
Gas production in landfills occurs from biological decomposition
with the major constituents being methane and carbon dioxide. However,
other gases such as nitrogen and hydrogen sulfide may be present.
These gases are of importance when evaluating the effect a landfill
may have on the environment because methane can explode and carbon
dioxide may dissolve to form carbonic acid with resultant mineral-
ization of ground water.
The principal way decomposition products from a landfill reach
the surrounding environment is through leaching. Production of leachate
may occur when ground water or infiltrating surface water moves through
the solid wastes. Leachate may leave the fill at the ground surface
as a spring or percolate through the soil and rock underneath and
surrounding the waste. Table 2 provides data from two studies which
12
indicate the quality of leachate from municipal solid waste.
II - 130
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Hydrogeologic and water quality studies of five landfills in
northeastern Illinois were carried out over a four year period in a
Solid Waste Demonstration Grant Project. The final report of this
project provides information on equipment and methods used for
13
monitoring of the leachates from these landfills.
Methods and equipment for sensing gaseous pollutants from
landfills are described in a recent paper. Portable combustible
gas indicators are available for measuring methane, oxygen and
hydrogen sulfide.
Figure 2 shows components of a gas sampling probe combined
with thermocouples and thermistors for collecting gas samples and
measuring temperature in an experimental landfill. These sensors are
used for monitoring at the experimental Boone County Field Site in
Kentucky where the Disposal Technology Branch of the Solid Waste
Research Division, NERC, Cincinnati, is conducting field studies on
land disposal of solid wastes. Gas samples are collected in glass
flasks valved to allow simultaneous exhaust of the flask and aspiration
of the sample into the flask. The samples are taken to the laboratory
for analysis by a gas chromatographic method.
Figure 3 indicates schematically the gas chromatograph set up
for sampling and analysis of landfill gases. The thermal conductivity
detector is used for measurement of oxygen, nitrogen and carbon dioxide
to values as low as 100 ppm. Methane and other hydrocarbons are
mea^ " Hmultineously with the flame ionization detector to values
as low as 1 ppm.
OTHER PROBLEM AREAS
Toxic materials such as mercury, lead, cadmium, zirc and
selenium are present in solid wastes. General]y the amounts are
small and do not constitute a health hazard* However, these materials
may be concentrated in incinerator stack emissions and wastewater.
Quantitative measurements have been made on selenium in paper,
mjnicipal solid wastes, incinerator stack emissions, incinerator
quench waters, incinerator residue and compost samples using a
spectrophotofluorescence method.
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Waste organic materials such as polychlorinated biphenyls
(PCB) and pesticides (DDT, Aldrin, Malthion, etc.) present an
increasing problem of disposal. A study of the decontamination and
combustion of organic pesticides and pesticide containers was
recently completed by Foster D. Snell, Inc. under a contract with
EPA. Pyrolysis decomposition products of the pesticides were
analyzed using a gas-liquid chromatograph and a differential scanning
calorimeter.
Special problems of industrial hygiene and environmental
pollution may occur in processing reclamation plants where solid
wastes, sewage sludge and other organic wastes are selectively re-
cycled, shredded, pulverized and converted into useful products by
composting or other means. Hammermills and other grinders of the
wastes produce dust and noise that can be hazardous to the workers
in the plant. Such plants are potential sources of odors and may
provide breeding places for flies and rodents. The gaseous and
liquid effluents from these plants may require monitoring to assure
that objectionable odors and harmful effluents are not entering the
surrounding environment.
A recent study on composting of solid wastes in the United States
provides information on engineering, chemical, microbiological and
environmental aspects of properly managed windrow and enclosed high-
17
rate digestion composting plants. Monitoring of temperature,
moisture and aeration of the material in windrows and digestion tanks
is essential for process control and for determination that conditions
suitable for destruction of pathogens are being maintained.
Agricultural crop and animal wastes also cause solid waste
problems which may require surveillance. A major pollution problem
of this type is the result of high density rearing and maintenance
of animals in the meat producing, dairy and poultry industries.
Stored manures from these industries can produce substantial nitrite
18
and nitrate pollution to ground and run-off waters. Furthermore,
Salmonella typhimumium and other diseases common to animals and man
II - 132
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capable of surviving current animal manure disposal procedures
and therefore must be considered for further research studies and
19
for possible future monitoring.
SUMMARY
Pollution from solid waste differs from air and water
pollution in that it tends to be more of a local problem. Major
environmental effects are caused indirectly by decomposition
products rather than the wastes themselves. Sensing techniques
are the same or similar to those used in the air and water programs
because the pollution caused by solid wastes is primarily from gases,
liquids and particulates that enter the air and water for transport.
Typical examples are (l) stack effluents from an incinerator dis-
charging particulate matter and noxious gases into the atmosphere
and (2) leachates from landfills contaminating ground and surface
waters. Toxic materials such as mercury, lead, selenium, pesticides
and PCS are potential pollutants from solid wastes. Surveillance of
other potential problem areas as recycling and composting plants,
sludges and manures also may be necessary.
ACKNOWLEDGEMENTS
The author wishes to acknowledge the assistance provided by
Messrs. T. W. Bendixen and T. J. Sorg of the Office of Solid Waste
Management Programs in ti, 5 development of this paper. Photographs
and some of the sensor and equipment information presented were
provi - ' "^r Messrs. E. W. Coleman, N. B. Schomaker and D. L. Wilson
of the Solid Waste Rec°qrch Diviei-n. ^-j.-- eciation is also acknowledged
for critical review and helpful suggestions by 0. A. demons and other
reviewers from the Solid Waste Research Division.
II - 133
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REFERENCES
1. Environmental Quality; The First Annual Report of the Council
on Environmental Quality, Transmitted to tl e Congress August
1970.
2. Policies for Solid Waste Management, NAE-N LS Report for the
Bureau of Solid Waste Management; EPA Pub. SW-llc. 1970.
3. Golueke, C. G. Detection of Pollution Caused by Solid Wastes.
Paper presented at Joint Conference on Sensing of Environmental
Pollutants, Palo Alto, California Nov. 8-10, 1971
4. Munich, A. J., A. J. KLee and P. W. Britton. Preliminary Data
Analysis; 1968 National Sur/ey of Community Solid Waste Practices
EPA Pub. SW-3s.
5. An Information System for Solid Waste Operation. Demonstration
Grant No. G06-EC-00135. EPA 1971.
6. Ulmer, N. S., Physical and Chemical Parame -ers and Methods for
Solid Waste Characterization. A Solid Was ,e Research Division
Open-File Progress Report. 1970.
7. Wilson, D. L., Method for Macrodetermination of Carbon and
Hydrogen in Solid Wastes. E & ST Vol. 5, July 1971, pages 609-614.
8. Achinger, W. C., and L. E. Daniels. An Evaluation of Seven
Incinerators. Presented at 1970 National Incinerator Conference.
EPA Pub. SW-51ts.lj.
9. Specifications for Incinerator Testing at Federal Facilities.
NCAPC, Durham, N.C., October 1967.
10. "Standard Methods for the Examination of Water and Wastewater,
APHA, New York, N.Y. 12th Ed. 1965
11. Peterson, M. L., Pathogens Associated with Solid Waste Processing;
A Progress Report. EPA Pub. SW-49r. 1971.
12. Brunner, D. R., and D. J. Keller. Sanitaiy Landfill Design and
Operation. EPA Pub. SW-65ts. 1971.
13. Hughes, G. M., R. A. Landon, and R. N. Farvolden. Hydrogeology
of Solid Waste Disposal Sites in Northeastern Illinois. Final
Report on Solid Waste Demonstration Grant Project G06-EC-00006.
EPA Pub. SW-12d. 1971.
II - 134
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14' jsanov, M. E. and V. R. Bowerman. Methods of Sensing Land
Pollution from Sanitary Landfills. Paper presented at Joint
Conference on Sensing of Environmental Pollutants, Palo Alto,
California, Nov. 8-10, 1971.
15. Johnson, H., Determination of Selenium in Solid Waste. E & ST
Vol. 4, Oct. 1970, pages 850-853
16. Putnam, R. C. , F. Ellison, R. Protzmann, and J. Hilovsky.
Organic pesticides and pesticide containers; a study of their
decontamination and combustion. Rockville, Md., U.S.Environmental
Protection Agency, 1971- (Distributed by National Technical
Information Service, Springfield, Va., as PB-202 202. 175p.)
17. Breidenbach, A. W., Composting of Municipal Solid Wastes in the
United States. EPA Pub. SW-47r. 1971
18. Gilbertson, C.B., T. M. McCalla, J. R. Ellis, 0. E. Cross, and
W. R. Woods. Runoff, Solid Wastes and Nitrate Movement on
Feedlots. JWPCF, 43(3): 483-503, March 1971.
19. Will, L. A., S. L. Diesch and B. S. Pomeroy. Survival of
Salmenella Typhimumium in Animal Manure Disposal in a Model
Oxidation Ditch. Presented at APHA meeting Minneapolis, Minn.,
October 12, 1971.
20. Thomas, C. 0. Airborne Sensing for Landiill Site Evaluation.
Pollution Engineering, November-December 1971> pages 32-33.
135
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TABLE I
Purpose
SOLID WASTE INFORMATION NEEDS
Types of Data Needed
Administration and Management
Research
Pollution Surveillance
(Monitoring)
Planning information
Waste quantities and characteristics
Cost and performance data
Environmental hazards
Legislative information
Trends
Generation factors
Characterization data
Solid Waste systems
Storage
Collection
Transportation
Processing
Recycling
Disposal
Design information
Cost and performance data
Environmental effects
"Waste location and composition
Significant effluents from
Landfills
Incinerators
Other solid waste systems
II - 136
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TABLE 2
COMPOSITION OF INITIAL LKACHATE*
FROM MUNICIPAL SOLID WASTE
Component
pH
Hardness, CaC00
Alkalinity, CaC00
Ca
Mg
Na
K
Fe (total)
Ferrous iron
Chloride
Sulfate
Phosphate
OrgMud c-N
NH.-N
4
BOD
COD
Zn
Ni
Suspended solids
Study
Low
6.0
890
730
240
64
35
28
6.5
8 /
0. (
96
84
0.3
2.4
0.?°
21,700
A
High
6.5
7,600
9,500
2,330
410
1,700
1,700
220
8.7#
2,350
730
29
465
',80
30,300
Study
Low
3-7
200
127
0.12
47
20
2.0
8.0
2.1
809
0.03
0.15
13
B
High
8.5
550
3,800
1,640
2,340
375
130
482
177
50,715
129
0.81
26,500
* Average composition, mg per liter of first 1.3 liters of leachate
per cubic foot of a compacted, representative, municipal solid waste
# One determination
II - 137
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RADIOACTIVITY SENSING - A CURRENT REVIEW
Vernon E. Andrews
Environmental Protection Agency
Western Environmental Research Laboratory
Las Vegas, Nevada
INTRODUCTION
The monitoring of radioactive environmental pollutants is based
on the special characteristics of radioactive materials. Because
of the variety of radioactive elements all facets of the environment
are subject to radioactive pollution and may require various degrees
of surveillance. As a result of several decades of development of
equipment for detecting and measuring radioactivity, a wide range of
systems of high sensitivity is now available. Although no single
paper can provide a comprehensive discussion of all radiation
measuring equipment and techniques, this review surveys those of
interest to EPA programs.
BASIS OF RADIOACTIVITY SENSING
Radioactive materials provide the source of their own detection
and measurement. Radioactive decay normally occurs by the emission
of charged particles - alpha and beta particles. The decay of some
isotopes is accompanied by gamma rays. The three types of radioactive
emissions are physically different, and although most radiation
detectors can be made to detect or measure all three, specialized
systems and techniques are generally applied to each type. This
specialization tends to increase the amount of equipment required
for complete environmental surveillance; however, it also serves as
a means of differentiating between the types of radioactivity.
Three basic types of radiation detectors - photographic film, gas
counters, and scintillation detectors - have been in existence since
the early days of radiation experimentation. Two relatively new
developments - solid state detectors and thermo-luminescent
dosimeters (TID) - have had profound effects on radioactivity
measurements.
II - 138
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Photographic emulsions are used for detection and quantitation
of all types of radioact:vity. Autoradiographs of environmental
samples are used to locate and quantitate alpha and beta emitting
particles. Of major interest in this discussion, is film dosimetry.
Film packets, or film badges, are used to measure personnel or area
exposures to gamma, and occasionally beta, radiation. The direct
physical action of radiation on the film results in a darkening which
provides an easily calibrated, reproducible measure of the amount of
radiation to which the film was exposed.
Three families of gas detectors are widely used. lonization
chambers measure the ionization of gas molecules in the detector.
The chambers are commonly filled with air at atmospheric pressure
or argon under a pressure of several atmospheres. Radiation exposure
is defined as the amount of ionization produced in air. The ionization
chamber instrument, therefore, provides a true measure of gamma exposure.
A second form of gas detector is the proportional counter. Rather
than measuring the ionization produced, the proportional counter measures
the number of ionizing events occurring within the chamber volume.
The signal produced by each event is proportional to the amount of
ionization produced by each event, which in turn is proportional to
the energy of the event for alpha and beta particles. Proportional
counters generally exhibit low sensitivity to gamma radiation. By
adjust.. -_ _-^ ionization amplification and discrimination on the signal
produced, proportional ^ winters ca1". bo ...„ " specific for alpha or
beta radiation.
Geiger counter systems, employing a Geiger-Mueller tube detector,
produce a signal pulse for all ionizing events occurring within the
detector volume. Gas amplification is adjusted so that the output
signal is the same for all ioniziug events. This detector is used
most widely as a gamma detector, although it will detect any
ionization occurring wit nan the chamber. Certain Geiger counters are
used as beta counteis.
— - 139
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ScinlLl Intinp, materials are widely employed as radiation
measuring devices. These materials have the property of emitting
light in amounts proportional bo the energy of the radiation particle
or ray absorbed within them. In various forms, they are used to
detect and quantitate all forms of nuclear radiation.
One of the earliest radiation detectors was a ZnS screen which
scintillates when struck by an alpha particle. Since the ZnS phosphor
is very sensitive and is specific for alpha radiation it is still
widely employed as an alpha counter.
Inorganic crystals of metal—halide salts activated with small
amounts of impurities are widely used as extremely sensitive radiation
detectors. The two most widely used inorganic crystal scintillators
are Nal(Tl) and Csl (Tl). By varying physical dimensions of the
crystals they can be made more or less sensitive to gamma radiation.
Very thin detectors are insensitive to gamma radiation, but very
sensitive to beta radiation. Scintillating crystals are used as
gross radioactivity detectors and to measure the energy of individual
radiation events.
Organic crystal scintillators, the most popular of which is
anthracene, serve the seme general purposes as inorganic scintillating
crystals. Their specia] characteristics such as non-hygroscopicity,
physical durability, and relatively low cost make them attractive for
many -applications in radiation measuring even though they are inherently
less sensitive than inorganic scintillators.
Several liquids also have the property of scintillating upon
absorbing radiation. These liquids are especially suited for measuring
low levels of beta radioactivity in specially prepared samples. Mixing
the sample with the scintillator allows for a detection efficiency
approaching 100 per cent. In addition, the proportional response
to radiation energy permits some discrimination on the signal allowing
the simultaneous counting of two or more isotopes which have differing
beta energies.
II - 140
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A hybrid scintillation detector is the plastic scintillator.
Thest.1 detectors use essentially the same scintillating compounds
used in liquid scinti]L"tors. However, the scintillating medium is
mixed with a clear plastic which is cast as a solid. Plastic scintil-
lators are less dense ard contain a smaller fraction of scintillating
material than crystal scintillators, thus have a lower efficiency.
This low efficiency i" improved somewhat in some plastic scintillators
in which lead is incorporated to increase density. Plastic scintillators
are insensitive to physical and thermal shock, are non-hygroscopic,
and are relatively inexpensive. Their primary advantage lies in their
machinability. They can be cast and machined in a variety of shapes
for unique and special applications.
The advances in electronics during the past decade have resulted
in a family of radiation detectors known as solid-state devices. These
detectors, such as lithium-drifted germanium diodes are used for
measuring all three types of radiation. Their main advantage is
extremely high resolution of radiation en<=:0les. ""his proviJoo Cai
excellent method of spectroscopy - or radiation energy identification -
of alpha and gamma radiation.
Another recent devslopment in detectors employes the principle
of thermoluminescence. Electrons in the crystal matrix of the TLD
are displaced by the energy of radiation absorbed in the TLD. Upon
heating the TLD, the electrons icturn to their lower energy levels,
emito±r% ^i^ht :n the process. The light is proportional to the
absorbed radiation. B, . ~° 01 their n_i.gh sensitivity TLD's are
replacing film in many dosimetry applications.
UNITS OF RADIOACTIVITY MEASUREMENT
Because of the differing physical characteristics of nuclear
radiation, two basic modes of expressing quantities are used in
surveillance. The first mode, which corresponds to that used in
relation to toxic pollutants, expresses the rate of radioactive decay
relat?v° to the unit volume or mass of the medium of interest.
II - 141
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Because of the amounts of radioactivity generally encountered in
the environment, concentrations are most commonly expressed as
picocuries (2.22 alpha or beta disintegrations per minute) per unit
mass or volume. These concentrations are generally determined from
laboratory analysis of samples; however, some media can be monitored
for the concentration of some radionuclides on a real-time basis.
In some cases the alpha and beta particles are counted directly.
In others the gamma rays are counted and are related by their known
abundance to the alpha or beta decay rate.
In addition to the potential for internal exposure to radiation
via inhalation or ingestion, external radiation exposure can occur
at a distance from radioactive materials due to the range of emitted
beta particles and gamma rays. Radiation exposure rates are defined
in terms of the ionization produced in air by gamma or x-radiation.
The unit of exposure is the Roentgen. Absorbed doses in tissue are
e.xpressed in terms of rads and are used for all types of radioactivity.
Absorbed doses, in rads, are essentially equal to exposure in Roentgens
for gamma radiation. Because of its penetrating nature, external gamma
radiation results in a whole body exposure, whereas beta radiation
delivers a radiation dose only to the skin or surface of the eye.
Portable radiation survey devices measure gamma exposure rates in
Roentgens per hour or, integrated exposures in Roentgens. Some also
have the ability to detect beta radiation, but the indications only
provide a measure of relative intensity.
Environmental sampling for radioactivity involves all media - «
air, liquids, and solids. Air sampling requires collecting three
sample types: particulates, reactive gases, and inert gases. The
same sampling techniques used for other airborne particulates are
applied to sampling for radioactive particulates. Depending on the
analytical techniques to be used, the filter media may be varied.
Since alpha and beta counting are routine techniques, a prime con-
sideration is in using a filter medium which exhibits surface collection
characteristics as opposed to depth-type filters. Commonly used filters
are glass fiber and organic membranes.
II - IL>2
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Both portable and stationary samplers are available to collect
samples over any desired period of time. In addition to collecting
samples for laboratory analysis, some samplers provide an analysis
of the samples during or immediately after collection. In one type,
a moving filter tape collects particulates fcr a pr?-set period of
time after which the collecting surface is mcved to an adjacent
radiation counter for counting while a new sample is being collected.
In another type a Geiger counter-detector is mounted adjacent to the
filter surface and measures the collected particulate radioactivity.
A unique sampler for monitoring the airborne concentration of radon
daughters uses a washer-shaped thermoluminescent dosimeter (TLD)
mounted near a membrane filter. Shielded against outside radiation,
the TLD exposure provides a measure of the airborne radon daughter
concentration.
Reactive gases are efficiently collected on activated charcoal.
These gases, primarily radioiodines, are measured by their emitted
gamma rays; therefore, collection in a depth medium does not detract
from the analysis. The activated charcoal may be in the form of beds
or cartridges inserted in a sampler secondary to a filter, or may be
incorporated into the filter medium.
Inert gases are monitored in several ways which are unique to
radioactive sampling. basic technique which has wide application
is the collection of compressed samples of a^r which are returned to
tne ~ -^oratory for direct counting or for separation and counting of
the gas of interest. These sample? mav be either short-term grab samples
or long-term integrated samples covering pe^ '.ids of up to a week. A
method employed at the Western Environmental Research Laboratory is
cryogenic sampling. Air is drawn through a bed of molecular sieve at
slightly above liquid nitrogen temperature. Noble gases trapped on
the sieve are removed and analyzed in the laboratory.
II - 143
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Sampling of milk, water and food is the same as for other pollutants.
The analyses vary, depending on the radionuclides of interest and their
concentrations. Soi - sampling is conducted in many surveillance pro-
grams. In all casee the analysis is performed in the laboratory, often
by radiochemir.try. Mo standard sampling techniques exist for soil.
Results are expressed as picocuries per unit mass of soil or curies
per unit area, usua]ly square miles or square kilometers.
RADIOACTIVITY MONITORING
Probably the widest variety of systems exists in radiation
monitors. Most monitors can be defined as in situ monitors. Monitoring,
or measuring of external exposures or exposure rates, is generally
conducted near the source of radiation. Monitoring of external
exposure rates is conducted with survey meters employing Geiger
counter, ionization chamber, and scintillation detectors. The
most widely used are Geiger counter survey meters. They usually
respond to levels of radioactivity down to tha background level and
operate to several Roentgens per hour. The probes are shielded to
permit measurement of gamma radiation only. A sliding shield can be
opened to permit detection of beta radiations also. Accuracy of the
exposure rate measurement depends on the comparability of the average
gamma energy being monitored to the average gamma energy of the
calibration source. A common calibration source is cesium-137«
The 0.66 MeV energy gamma approximates the average energy of mixed
fission products.
Ionization chamber survey meters in common use are generally
applied in situations where the exposure rates vary from several
milliroentgens per hour to tens or hundreds of Roentgens per hour.
lonization- chamber designs using pressurized argon chambers respond
to below-normal background ranges. Large volume ionization chambers,
such as the Shonka chamber provide accurate measures of exposure rates
at background levels, but are sensitive to environmental changes.
They serve as research devices, or to compare to exposure rate
measurements made by other sensitive survey methods.
[I - 144
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Scintillation survey meters using small Nal (Tl) crystal
detecuors provide extreme sensitivity at background levels. Accuracy
is very dependent on ^;\r,ma energies. Because of the requires
detector packaging they detect, gamma radiation only. Large scin-
tillation detectors are used at the WERL in aircraft for locating
and tracking radioactive plumes. These large detectors are also
used in vehicles to survey large areas on the ground while mobile
on highways and streets.
Several types of integrating radiation monitors or dosimeters
are used for in situ monitoring. Film badges are the most widely used
at the present time. Their low cost makes them attractive for
continuous large scale monitoring. Film badges are unable to measure
environmental background, levels of radiation, but are relatively
accurate at exposure levels above 30 milliroentgens exposure. TLD's
are replacing film badges in many areas because of their ability to
measure exposures from one milliroentgen or less to several Roe^.tgens.
Various types of TLD's are available, including powder, chips and
enclosed types with the medium baked on a heating coil to facilitate
readout. Although the initial cost is high, the TLD's in use provide
long service and do not require the processing facilities needed for
film processing. Another type of dosimeter is the personal pocket
dosimeter. An electric il charge applied to a small galvanometer is
dissipated in a radiation field. In self-reading types the accumulated
exi ^- —^ is visible on an internal scale. Others require a reader to
observe the exposure. These typ<=s ~^ ^simeters are used mainly in
industrial application.
Remote radiation monitoring falls into two classes, (l) telemetry
from a detector at the source of radiation to a receiver and readout
at some remote location, and (2) measurement of gamma radiation at a
location some distance from +^G source of the radioactivity. Although
not in wide use, the latter technique has some important applications
to environmental surveillance. Specially designed systems, such as
uhe EG&G Airboi-ie reflation Monitoring by^^m measure ground levels
of radioactivity from an aircraft at approximately 500 feet above the
surface. This allows rapid monitoring of large areas in a short time.
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The detectors are large Nal (Tl) crystals with an automatic sub-
traction of background cosmic radiation and correction for altitude.
Portable systems have at times been available to do a similar job,
but with much lower sensitivity.
Hard-wired remote systems, employing any form of radiation
detector, are used in a number of industrial applications. These
systems can be connected to meters, recorders, or alarms.
Radio-telemetry of radiation monitoring data is limited in
application. At the WEltL, a radio-telemetry system using a Geiger
counter detector is dropped by parachute from an aircraft flying above
a radioactive cloud. The radiation data is radioed to the aircraft
where it is displayed on a strip chart recorder in real time as the
parachute is descending. These systems can also be dropped into
areas inaccessible to mobile monitors to obtain ground level tele-
metered radiation exposure rate measurements.
Directional radiation detectors, sometimes referred to as gamma
telescopes, are used in both ground and aerial applications of remote
monitoring. Sensitive radiation detectors, usually scintillators,
are shielded or collimated so that only radiation from a preselected
sector can enter the defector. These are used to locate an airborne
radioactive cloud relative to the detector.
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DATA MANAGEMENT FOR MONITORING PESTICIDES AND RELATED COMPOUNDS
G. B. Wiersraa and H. Tai
Office of Pesticide Programs
Environmental Protection Agency
Washington, D. C.
When first told that we were to talk on "Sensor Data Management",
we immediately thought In terms of computers. As we gave more thought
to the subject, the idea of talking strictly about computers seemed
to only cover part of the problem. When talking about data manage-
ment, we are really talking about management of the entire flow of
information within a monitoring system. That is from the time it is
collected in the field to the time that it is either published in
open literature or presented to administrative personnel for action
and consideration. It is this approach that we would like to discuss
today. We will try to keep the principles and concepts in a general
frame of reference, but, where necessary, we will illustrate with
examples from our own experiences.
At a previous meeting in Las Vegas, the definition of monitoring
was discussed. Out of that discussion came two ideas. One was
monitoring for enforcement and the other was ambient monitoring.
Ambient monitoring is C' nducted to determine background levels, to
identify amounts present in a media and to determine trends through
t-imp. It is this type of monitoring that we will limit our discussion
to toaa;y.
In a successful a*/ .. ni managed monitoring system the first
phase is the planning and the collection of raw data from the field.
Certain basic principles are involved in data collection. First, the
objectives must be defined clearly. Precisely what are you monitoring
for? For example, in pesticides, we define what pesticides, chemical
contamtnctec and heavy metal residues are of interest. Another
fundamental objective is what are you trying to do with the data?
The Np-Hrinal Pesticide I onitoring Panel wrestled with this subject
for a good deal of time. They came to the conclusion that, in
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pesticide monitoring, the fundamental objectives should be to determine
the presence, levels and changes in time of pesticide residues in a
media. Other monitoring systems will have different objectives, but
these must be defined prior to implementation in the field, (l)
Second, you must define your sampling population. You cannot
send a field team out with just the objective of simply collecting
environmental information or samples. They have to be told precisely
what kind of samples to collect, where to collect them and how to
collect them. In addition, so that your data will make some kind
of sense, a certain amount of homogeneity has to be established about
the sampling population. For example, to facilitate data organization
and analysis in monitoring of soils for pesticides, the United States
was divided into two general categories, cropland and noncropland. (2)
The third principle of data collection is to employ a sound,
statistically based sampling design. This is of critical importance,
particularly if some estimate is required on the reliability of your
data about the occurance, the amount and the change through time of
the pollutants detected.
The fourth principle is to maintain consistency in collection
of samples. They should be collected using the same techniques
and procedures at each ;3ite. This requires that the people handling
your data collection be properly trained in the correct procedures
and maintain sufficient caution to eliminate the possibility of cross
contamination of the samples. Once the sample has been collected in
the field, it should be sent, as rapidly as possible, to the laboratory.
Care should be taken to insure that the samples arrive in a condition
closely approximating their natural state. Once a sampling team is
in the field, they should obtain as much information as possible about
the site while there. In our monitoring program, in addition to soil
and crop samples, the inspectors collect the following information on:
1. The crops that are grown on the sampling area.
2. How much irrigation was used and how many inches
of water were involved.
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3. The pesticide or fertilizer used in the year of
sampling. This includes the amount applied, the
crop it was applied to, what it was used for, its
formulation and method of application.
This information has been invaluable in the evaluation and
interpretation of information generated by our monitoring studies.
Once the samples have been properly collected and sent to the
laboratory, the second phase of data management begins. This is
the extraction and analysis of the raw environmental samples to
determine contaminant levels. In our case, these include pesticides,
heavy metals, PCB's and other chemical contaminants.
When we look at the general principles of the analytical tech-
nology of the pesticide residues, the important ones are the sensitivity
and the selectivity of the method. The general trend has been to
develop analytical methods specific for a particular pesticide or
a particular group of pesticides, and sensitive to a level of 0.1 ppm,
or even down to 0.1 ppb. The basic operations of the analytical
procedures are (a) subs;;mpling in the analytical laboratory;
(b) separation of the residues from the sample matrix, or extraction;
(c) removal of interfering substances or clean-up; and (d) identification
and determination of the residue. In case the identity of the pesticide
to be analyzed is not k, jwn in advance, the confirmation procedure may
become a distinct operation all by itself. This operation can be
elaborate and costly, in terms of both the manpower and the analytical
equipment re'4u ired for the identification of a component at a
concentration of 1.0 ppr;j.
Specific chemical reaction and spectrophotometry were, in the
early days, the principal analytical methods of identifying pesticides.
As both the type and the use of pesticides have grown more and more
complicated, the development of analytical methodology has inevitably
evolved around a technique known as chromatography, a separation
technique by which a mulbi—component mixture, passing through a
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separating medium, can be divided into individual components
according to, generally speaking, their molecular weight, size or
structure.
Column chromatography which generally refers to separation of
liquid or dissolved substances has been particularly useful in the
clean-up steps.
Gas chromatography, which deals with the separation of volatile
compounds, has been developed as the mainstay of the pesticide
analytical procedures. Due to the availability of a specific and
sensitive detecting system, most, if not all, the recent "multi-
detection" or "multi-residue" analyses have utilized gas chromatography.
The essential analytical procedures described are as follows:
1. Extraction: The fir.''t step in preparing a sample is to
extract the pesticide residue from the material. Since
no single solvent car, dissolve or extract all known
pesticides, the selection of solvent will naturally
depend upon the type of pesticides find the matrix
material. A great variety of solveni s or mixed solvents
have been used. The most common one:; are pure normal
hexane, or normal hexane mixed with r.sopropanol, acetoni-
trile, acetone, ether or mtthylene chloride. The methods
of extraction include shaking, rotat ung, or the use of an
extractor, such as Soxhlet extractor.
2. Clean-up: This is a step of separating the pesticide
residues from the bu]< of co-extracted materials. Two
basic techniques are commonly applied:
a. Partition - The extract is further extracted with an
immiscible solvent. Ideal separation would be that the
pesticides go into one layer while all other materials
remain in another layer. The knowledge on the solubility
of pesticides in various solvents, and its partition
coefficient, or p-value, between solvents is of prime
importance for a .successful and quantitative partition.
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b. Column chromatography - Some materials, especially
lipids, peptides, fats and oils, have similar
solubility as pesticides, and are difficult to be
separated by partition only. The so-called "column
clean-up" has become the essential step in handling
biological samples.
The extract, or the partitioned extract, is introduced
onto a column containing a separating medium, then eluted
with a solvent, pure or mixed. The most commonly used
column material is made up of mixture of magnesium and
silicon oxides. The eluate is then concentrated to a
definite volume, and ready for the final step; i.e.,
qualitative or quantitative analysis.
Separation and determination of pesticides. More often than
not, the extract contains a group of pesticides and their
decomposition products. All forms of chromatography,
including paper, thin-layer and ge \ have been used for thi
final stage of analysis. Among these chromatographic
techniques, gas-liquid partition chromatography (GLC), or
gas chromatogrrphy (GC), has been the most widely applied.
Extensive rese; rch has been carried out on its application
to quantitative analysis, especially in the field on the
specific detectors.
A detailed discussion on gas chromatography is beyond
the scope of tnis ^usentation. However, two fundamental
operating parameters are briefly described as follows:
a. Column materials usually have a thermally stable
compound, the stationary phase, coated on an inert
material, the support. The most commonly used
stationary phases are (a) polysiloxanes such as
DC-200, SE-52, OV-17 or its fluorinated derivatives
such as QF-1; (b) polyethyT^e jrlycol polymer such as
Carbowax 20M, or (c) hydrocarbons, such as Apiezon.
The support materials ; re usually diatomaceous earth,
fire brick powder, Teflon or glass beads.
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b. Detectors most frequently used include:
(l) Microcoulornetric detector - for halogen-
containing or nitrogen-containing compounds.
(2) Electron capture detector - for compounds
containing electronegative atoms, especially
chlorine.
(3) Alkali-metal modified flame ionization detector-
for selective detection such as phosphorus
(4) Flame photometric detector - for selective
detection such as phosphorus or sulfur.
The complexity of pesticides, i.e., the type, the use, the
matrix and the reaction and decomposition, has been a challenge to
analytical technology in both qualitative and quantitative analysis.
While the exact application of general analytical principle varies
with specific circumstance, the accuracy, or the authenticity of
analytical results of a certain procedure has been of great concern
to the users. Collaborative study to establish the validity has
been the practice. The general trend in the pesticide analysis is
the development of well-defined analytical manuals as an
authoritative guidance. Agencies such as FDA(3), Water Quality
Office (4), Perrine Laboratory of EPA (5) and Food and Drug
Directorate of Canada (6) have published comprehensive texts on
pesticides analysis.
In the laboratory it is necessary to maximize information
obtained from each sample. In our case, we try to analyze each sample
for as many pesticide classes, chemical compounds and heavy metals
as practical. This requires that we schedule our chemical analysis
and the flow of samples through the laboratory to take advantage
of the different degradation rates among pesticides and chemical
compounds. Those most likely to degrade rapidly in storage will
be analyzed first.
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We maintain n sample library. Whether ibis would be practical
for all media and monitoring programs is debatable. Since we collect
prJ narily soil and crop samples, it is a highly valuable and
important part of our operation.
After the data has been collected and chemically analyzed, the
raw data is transferred to a central staff. Their responsibility
is to analyze and interpret the data so that it is useful to decision
makers and others. This is the third phase of data management. The
first principle governing H.ita analysis is the function and structure
of the central staff. It is important that this staff originally
plans and manages the flow of information from the field to the
laboratory. Naturally -an effective system requires extremely close
coordination and liaison between the laboratory staff, the field
personnel- and the planning and analysis staff. This staff should
consist of people who have expertise in the areas of primary
con-em, as well as sound ecological training.
A second principle of data analysis is, do not attempt to
extract more from the d ita than was set forth in the original
objectives. I believe that many monitoring programs fall short
at this point. It is critical that we maximize information from
a sample collected in the field, but, in attempting to do this, we
should never attempt t'< Iraw conclusions and inferences from our
data that are not justified by the original sampling objectives
ano designs.
A thira principle of data analvsis is the proper use of computer
support. We would say the cx-J-tical first s^c~> is that there is a
careful edit of raw data sheets by not only a technicinp but, where
appropriate, by professionals. We have found that several man days
of professional level review have paid off in a reduction of errors
and an increase in the confidence we place on our information. When
establishing a computer support program, it is necessary to make
certain that the program, as established, is flexible and responsive
to chaii&oD tliat are bound to occur in ^^ -~c handling of the data.
We allowed the programmers to develop their techniques with a
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minimum of interference. To aid in the development of a viable
program, we kept the analysis of data as simple as possible and still
be consistent with our seated objectives. We minimized the addition
of new ideas and the institution of too many changes. The only
changes we initiated during the developmental stage were those that
could not be instituted after completion of the program. When our
program was completed} we tended to initiate changes and additions
cautiously, finding that many times ideas that seemed pertinent
at the time were not quite as valuable several weeks later.
May we point out the value of the programmable calculator.
These machines are, in practically every sense a desk top computer
unit. We use our's for mathematical and statistical analyses. This
has saved us a great deal of time in analyzing data. As an example,
a regression analysis at the computer center would take two weeks
including data preparation, key punching and analysis. This same
amount of data was analyzed using a programmable calculator in less
than an hours time. The presence of such a strong analytical tool,
readily available, allows you to conduct data analyses in great
depth because it frees you from the time consuming and monotonous
calculations required on machines of lesser capacity.
A fourth principle of data analysis is the proper application
of statistical analyses to the data. Statistical analysis actually
begins when planning field studies. That is the implementation
of a statistically sound sampling plan, and it is the foundation of
all future data analyses.
The next step in statistical analysis is to define the
distribution form of your data. In pesticide residue data, the
normal distribution is not appropriate because we have found the
data to be severely skewed to the right. This can be somewhat
alleviated by transforming the pesticide residues to logarithms.
Tests have shown that while this transformation does not truly meet
all the requirements of the normal distribution, it is close enough,
and we have used it in lieu of better transformation.
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A second problem in pesticide analysis is what to do with
zeros. Somewhere between 25% and 75% of the data collected in
the field either has pesticide or contaminant residues below the
detectable limits of our chemical assays or e_,-se residues are truly
absent from the sample. In environmental monitoring work a miss is
as important as a hii. How are these zeros to be considered in the
analysis of data? Urfortunately, we have not had the same success
in handling the zero problem as we have had with transforming the
distributions. One technique we have used is to determine the
frequency distribution "or a particular land area, either a biome,
state or group of st;te3, and calculate this frequency distribution
either using probit ana Lysis or a transformation involving standard
deviates. This type of analysis has provided us with a good picture
of the distribution of i pesticide residue through a medium, and it
has allowed us to pL-ice confidence Intervals ibout the levels we
have detected.
Despite the obvious use of statistics in data handling, sometimes
the best method is sj.mply to forego any statistical analysis.
In the fifth principle of data analysis it is necessary to
attempt, wherever po: si xLe, to coorelate the monitoring data collected
in one system with tl at data collected in other systems. This
correlation will beg.n .i/ith the central operational staff mentioned
earlier, but tae more sophisticated correlation of this data should
My take place at i higher echelon. In EPA, for all monitoring
data, this would most logical'y n~" "^nducted by the Office of
Moni toring.
All this effort ic. worthless if the information i s not put into
a ui-able form and presented both to the administrators nnrj decision
makers within the organization. In addition, it should be r
-------
Up to now we have been talking about sensor data management for
present systems and most of these, at least for pesticides, do not
utilize remote sensing techniques. What are the potentials for
remote sensing of pesticides? How will they influence existing
monitoring networks? In the short time remaining, we would like to
consider remote sensing for pesticides, the techniques and possibilities.
A review of the literature reveals that remote sensing techniques
have been applied to detecting a wide variety of environmental
parameters. Anuta and MacDonald (7) used multi-spectral photography
taken from satellites to identify soil, salt flats and water surfaces.
Peake (8) used microwave radiometry to detect soil moisture levels in
the upper 2«-3 meters of the soil. A variety of techniques are being
tested for the remote sensing of various pollutants in the air. Some
include using shifts in sound frequencies (Doppler effects) to measure
wind profiles in the boundary layer (9). Another technique is to use
optical correlation methods to identify certain gaseous pollutants (10)
and Leonard has reported on the use of Raman Spectroscopy to identify
NO and SCL but with limited success (ll).
Burgess and James (12) used aerial photographs to trace pulp
mill effluents in marine waters and claimed success. Fisher (13)
reported mixed results when trying to identify pollution zones in
estuaries using infrared Ektachrome color film with a dark red filter
and Kodachrome X with a UV filter. Microwave radiometry has been
tested for possible use in identifying oil slicks in bad weather or
at night (14)»
The cited references are hardly an exhaustive review of the
literature, but are given as examples of current attempts to utilize
remote sensing techniques to monitor environmental parameters.
None of the above studies were conducted to determine the
feasibility of identifying pesticide residues using remote sensing.
To do so using present techniques would certainly be stretching the
state-of-the-art. However, we are encouraged by the possibilities
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inherent in present remol.e sensing techniques that could make remote
sensing of pesticide res'dues a reality within the relatively near
future. One area of particular promise is the use of induced
luminescence using UV and visible lasers. Gross and Hyatt (15)
reported on the use of laser beams to identify a wide variety of
surface materials. The concept basically is that the laser beams
induce momentary luminescence in a material and that different
materials have different signatures which are detectable at very low
levels. Using this method they were able to obtain characteristic
signatures for a variety of surfaces including Teflon, epoxy, light
and dark phenolic surfaces, a variety of different kinds of leaves
and certain minerals and oils. It is very speculative at this time
to predict the usefulness of a method like this for identifying
pesticide compounds. Certain basic research would have to be under-
taken to test feasibility of this approach. They are as follows:
1. The relative merits of passive versus active sensing
will have to be investigated. If active methods are
used it will be necessary to determine what frequencies
are most efficient for detecting pesticide residues.
2. Both the infrared and Raman Spectra for various pesticide
compounds will have to be identified and selections made
of the characteristic identifying bands.
3. The background spectrum data in natural environments will
have to be studied and variations noted due to media,
season, tirr.° <">f day, over L-^n cover, etc.
4. The type of sensors best suited to detecting pesticide
residues will have to be identified and developed.
5. Actual field tests will have to be made to test
the procedures
6. In the beginning, remote sensing will have to be
complimented by extensive ground-truth studies.
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If we allow ourselves to dream, it is exciting to picture an
effective satellite based remote monitoring system for a wide range
of pesticide residues. This same system could also be easily
adapted to identifying other chemical contain: nants and possibly heavy
metal residues. The results from the satell: te could be telemetered
back to a central processing point. This wotId be a virtually real
time pesticide monitoring system. If properly managed, it would
provide an instantaneous picture of pesticide residues in the
environment.
When the time comes for setting up the data management system,
we should be able to take advantage of those systems already in
existence which are designed to handle other forms of remote sensing
data. The basic principles of data handling will remain the same,
but the mechanics of data handling will certainly be considerably
different.
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LITERATURE CITATIONS
(l) Anon. 1971- Annua__ Report: Working Group on Pesticides,
Council on Environmental Quality. Washington, D.C.
(?) Wiersma, G.B., P«w Sana and. E.L. Cox. 1971- A sampling
design to determine pesticide residue levels in soils of
the conterminous United States. Pesticides Monitoring
-Journal Vol. 5(l): 63-66
(3) Anon. 1967* Pesticides Analytical Manual. Food and Drug
Administration, Department of Health, Education and Welfare.
Washington, D.C.
(4) Anon. 1971. Water Quality Office. Methods for organic
pesticides in the water and wastewater.
(5) Anon. 1967• Analytical Manual. Perrine Primate Laboratory.
Environmental Protection Agency. Perrine, Florida.
(6) Anon. 1969. Analytical Manual. Food and Drug Directorate
of Canada. Ottawa, Canada.
(7) Anuta, P.E. and R.Ii. MacDonald. 1971- Crop surveys from
multiband sat el '.itr photography using digital techniques.
Remote Sensing of the Environment. Vol 2(l): 53-6?
(8) Peake, W.H. 19''9- The microwave radiometer as a remote
sensing instrument. The Ohio State University Electro
Science Laboratory
(9) Little, C.G. et al. 197(). Remote sensing of wind profiles
in tlie boundary Jaxer. Knvironmenbnl Science Services
Administration. ESSA Technical Report Elil, 16H-WPL 12.
(10) liarringer, A.R. anc J.H. Davis. 19u9« Experimental results
in the remote sensing of gases from high altitudes. IN:
Second Annual Enrth Resources Aircraft Program Status Review.
Vol 2. Agriculture and Forestry Sensor Studies, Section 34.
- 159
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(1. ) Leonard, D.A. 1970. Feasibility study oJ remote monitoring of
gas pollutant emissions b/- Raman Spectro scopy. Avco Everett
Research Laboratory. Rerearch Report No,
(12) Burgess, F.J. and W.P. Jerries. 1970. Aerial photographic
tracing of pulp mill effluent in marine /aters. Department of
Civil Engineering, Oregon State Universi /y.
(13) Fisher, J.J. 1970. Criteria for recognition of estuarine
water pollution by aerial remote sensing. Department of Geology,
University of Rhor1 1 Island.
(14) Edgerton, A.T. - id D.T. Trexler. 1970. Radiometric detection
of oil slicks, Aerojet General Corp. , EL Monte, California.
Report No. SD-1335-1.
(15) Gross, H.G. and H.A. Hyatt. 1971* Lumiiescence induced by
IR and visible lasers for the remote act i_ve sensing of
mcterials from ground air and space. McDonnell Douglas
Astronautics Co. , MDCG 2344.
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PART II
E. Workshop Discussion Top: cs
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WUKKSHDP DISCUSSION iXJf U-
WORKSHOP I - Sensor Monitoring Techniques
The following aspects of sensor and sensor-typt-s are proposed for
discussion for monitoring environmental pollution:
1. Current role of automated contact and non-contact sensors
in EPA1 s established programs and what are problems pre-
venting wiJer utilization of these sensors.
2. What future requirements are envisioned for automated
contact and non-contact sensors.
3. A discussion of the use oi sensors in monitoring enforcement.
4. A discussion of various contact and non-contact sensors now
in use from the point of view c:' their applicability to point
source monitoring an i extended erea monitoring.
5. A discussion of methods for and possible degree of automation
in the acquisition of data.
6. Sensor technology utilized by other agencies for environmental
application.
WORKSHOP II - Sensor Platforms
Sensor platforms suitable for identification a id monitoring of
environmental pollutants fill be considered. >ensor platforms are
to include all faciliti*..* from which either co itact or non-contact
measurements and data links may be deployed. is such, mobile or
stationary sensor platforms nay b° established,
1. on <.* 0t.i«eth the land surface;
2. on or withiu ^ ---or b&a>;
3. on or beneath a Jea oed;
4. in the atmosphere; or
5. in space.
Panel A wi 1 consider 1-3 above. Panel B will consider 4-5 above.
Both panel:, will ask atteidees to participate in discussions
regarding:
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1. Platforms now being utilized in the field at Regions
and NERC's. It is expected that a list of platforms
be constructed to match specific needs, i.e., in (2)
above, delineate the use of small boats, barges, buoys,
and subaersibles. Future possibilities and capabilities
should be similarly outlined*
2. Region, NERC and Headquarters representatives should identify
platform types that could be used now and deemed desirable in
the future, ignoring availability. Also identify the type of
use, e.g., continuous monitoring or special short-term investi-
gations for monitoring or enforcement purposes. Also identify
relative needs in terras of large area or small area monitoring.
Consider:
a. aircraft for air, water and terrestrial surveillance
or investigations, e.g* EPA aircraft, other government
agency aircraft, private aircraft, commercial airlines,
balloons and dropsondes;
b. sea and inland watercraft, buoys, etc.;
c. land platforms, e.g., vehicles, mobile labs
and fixed stations;
d. spacecraft (NASA representative may identify
available and planned platforms),
3. Deployment should consider region and NERC needs in terms of
a. do all (or specific) regional offices and NERC's
need specific types of platforms available at
their location, or can one or more NERC provide
support to all Regions;
b. reviewing factors affecting deployment, such as
estimated use periods, costs of acquisition,
maintenance and operational manpower requirements,
support facilities such as shops, laboratories and
vehicles, mobility and reaction times required.
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4. Review platforms currently exi«. ig in other agencies.
These may or may not be availabl_ EPA on a cooperative
or contract basis. Review past cooperative and contracted
efforts for sensing programs with other agencies. Identify
desirable cooperation that was soug".£ but could not be
obtained, or should be pursued.
WORKSHOP III - Sensor Data Manages*nt Workshop
Panel A - Current Pat^ Systems Panel
The purpose of this -i.el is to uncover Regional needs for data
management systems. Ot necessity, current systems must be discussed
and their advantages and shortcomings from the regional point of view
indicated. The follow! .g areas are suggested as basic items for
discussion:
(1) the utilization of cur.;-ant E?A data management systems
by the Regional Offices;
(2) the response of the data systems to p esent needs. Do
the systems provide all the outputs n. eded by Regional
Offices, is the response timely, are the present systems
easily querried, etc.;
(3) requiiements on current systems co insure quality control
and standardization. Is the date froi state-of-the-art
sensors treated in the same manner as wet chemical
measurements? Is the data from &11 sources given equal
weight, etc.;
(4) c ordination of EPA data management with other Federal,
S ate and municipal agencies. What is level of coordination,
etc.
Panel - B - Feature Data Management/Pi scussion GJide
1. A national/regional environmental data Distribution Infrastructure.
a. In?; des SPA and non-EPA monitoring capabilities;
b. sat eli. a systems (ERTS, GOES, EOS, etc.);
c. groutd based h< Jware (communication sjstems and computers);
d. organizations elationships and responsibilities.
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PART It
F. Workshop Panel Summari '
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SENSOR MONITORING TECHNIQUES WORKSllOl1
Panel h - Contact Sensor Techniques
Panel Chai^. .;;i, ^. Krawczyk, EPA
HISTORICALLY
The water program at the Federal level acquired or developed
sensor systems to measure pollutants at site locations on rivers,
lakes, and streams. The prototypes were tested on t-ne Ohio River
arid produced data for measuring water quality. When these in situ
sensors were developed, it was the aim of the program to produce
equipment which would require a minimum amount of maintenance (once
a week visit to a site by a technician to calibrate and check sensor
for output).
The air program went to the instrument manufacturers and pointed
out their nerds for measuring constituents in at ibient air. The pro-
prietary instruments WTO produced to the needs and specifications of
the air monitoring pro ;ram to measure appropriate constituents in
ambient air. These instruments were then made available through
grants to state and local air monitoring agencies. The state and
local monitoring systems would ise the instrumentation to collect
data and samples. The data and samples would then be .Tent to the
appropriate Federal air laboratory for further analysis.
PRESENT ROLE
The panel and Bill Siyers in his talk provLded input that the
Federal water program has approximately 60 site,, where in situ sensors
measure dissolved oxygen, temperature, conduct!/ity, pil, oxidation-
reduction potential, chloride, turbidity, and solar radiation. There
are a total of approximately 30') sites in various locations operated
by federal, state, interstate, ind local agencies that measure from
2 to 12 parameters. Of the 300, 89 arc identified in the Chemical
Engineering News articles of September 20, 1971, pages 16 through 20.
I - 164
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Dr. D. S. Earth, in his paper presented on November 30, 1971
at this workshop and re-emphasised in the panel discussion, pointed
out the availability of instrumentation for measuring SCL» oxidants
(ozone), carbon monoxide, total hydrocarbons, NCL-NO , and particulates.
f~~ X
This instrumentation was placed on close proximity to air sampling
devices and samples were manually transported from the sampling site
to the laboratory for treatment and analysis.
The members of the panel pointed out that air pollution problems
usually occur in high population density sites. These sites of
necessity contain local laboratories (state local) where samples of
air are collected and run daily. EPA (formerly the Air Program)
provides monetary and technical support for these laboratories.
The Air Program has gathered field base line data at a variety
of locations so that some normal ambient level can be established.
Coupled with this on site response, the air network collects samples
for submission to the air program laboratory for further analysis.
Computerization of data is a must in use of in situ measurements.
The dala 13 either put on tape and read into a computer, telemetereu
directly into a computer, or any combination of these systems to
provide information. The^e are systems which compare : ater quality
standards with in situ re.il time sensor data and flag violations.
The very nature of water ; monitor sensor and air sampling location
identify them as poa^t source data collection systems.
A considerable amount of the panel's time was devoted to the use
of data in the le^jl arena. It was pointed out that the data provided
by the sensor's must be a^cu. _'? and precise. The route of collaborative
testing provides precision and establishes accuracy in the conformance
to rigid specification of operation and maintenance and calibration.
It was the view of the chairman that the establishment of precision,
accuracy, and the reliability of the sensor had been accomplished
through the Analytical Quality Control Program in the water area under
the auspices of the AQC Research Program. It was the view of Dr. A. P.
Altshull^ th"t the production of standa^ ^ases for calibration purposes
and a Quality Control Program provide precise and accurate data.
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All of the regions have at least one in situ water monitoring
station and all large population areas have air monitoring stations
(sensor in this case is the collection of sample and rapid analysis).
The data that is collected is evaluated and summarized to'invoke a
response such as initiating action. The disclosing of air quality
data is normally accomplished through daily notification in local
newspapers and reported in the television and radio media usually
as part of the weather report.
The regional people would like to see the production of suitable
biological and microbiological in situ sensors which could alert the
agency to the presense of a toxic waste situation or to a potential
health hazard through bacterial contamination. The production of a
rugged sensor which will function in gross pollution situations was
also the desire of a number of panel participants.
The development of ion selective electrodes seems to hold some
promise especially if it becomes essential that effluents be monitored.
All in all, in the view of the chairman, the input and output of this
panel was vigorous, stimulating, and in retrospect, hopefully
productive.
What is really needed now is the establishment of appropriate
lines of communication between the regional people and OEM when
specific needs are identified to remotely measure a pollutant.
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SENSOR MONITORING TECHNIQUES WORKSHOP
Panel B - Non-Contact Sensor Techniques
Panel Chairman, S. Verner, EPA
I think I can honestly say that the panel on non-contact sensor
technology produced a full and frank discussion of problems associated
with these instruments. The discussion, at tin.es, spilled over to
monitoring strategy with particular emphasis or remote sensing
technology.
One of the first panelists to conment in this workshop pointed
out, and very cogently I might add, that Sensor System requirements
must be based on environmental standards, which are not only specific
as to the pollutant and the level of pollution, but also indicate
accepted techniques for sampling the pollutant. Wherever such
standa.ds exist, newer developed sensing techniques will have to be
compared with these standards and at the very east perform equally
as well as existing techniques in order to be widely adapted. Where
standards do not yet exist it is difficult to imagine how sensors can
be accepted into an operational monitoring program. At the same time,
however, I think it is not unreasonable to expand effort in develop-
ment of non-contact sensors - especially when orospects seem good for
developing a particaiar sensing technique - evon where standards do
not j^ Hst. Since Dr. Altschuller described the other day how
long it takes t,o deve^on ard field ti^L, -L.jtruments, and with the
anticipated rapid evolvement of new standards in the next, year or
two, we Cc'in confidently expect these new standards to be promulgated
well before a new generation of sensors are ready for evtluation.
At this point one might ask, why do we need non-contact sensors;
is it reasonable to justify the expenditure of large sums of hard-to-
finc money to develop these instruments? It was quickly pointed out
by several of those present that the potential of non-contact sensors
when employed in a rtu. :te sensing mode to cover large, even vast
geographic areas in a relatively short time and to pinpoint environ-
mental problems is so superior over other sensing techniques that
it is in^.ed well worthwhile to expend these fuids.
II - 16?
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Non-contact sensors, particularly photographic techniques, are
unrivalled in detecting the extent of haze and smog conditions,
smoke-stack emissions, outfall and effluents discharged into rivers
and lakes, up wellings, thermal pollution, algal blooms, sedimentation,
etc.
Sid Whitley of NASA's MTF Facility discussed how a photograph of
the earth taken in UV light showed a very distinct haze or cloud
condition which was not discernable to the eye nor to any other
photographic light wave band.
Other non-contact sensors, often based on electro-optical
instrumentation involving correlation or matched filter techniques
and derivative spectrometry, show great promise of detecting many
atmospheric pollutants, particularly those whoso resonance absorption
lines lie in the near IR thermal region. There is a practical reason
why the near thermal IR region is a cut-off for these instruments and
that has to do with the sensitivity level of the detector. The best
solid state detectors today such as Pb Se or Hg-Cd-Te can operate out
to about 10m with no cooling or at most thermo-electric cooling.
Without cryogenic cooling requirements, these instruments become
much more practical.
A great many non-contact instruments have already been built which
have qualitatively detected many atmospheric pollutants such as oxides
of Nf Sr and C, as well as hydrocarbons, NH_, etc. It is understood
that North American Rockwell has built a second derivative spectrometer
which has detected several impurities in water.
As important as qualitative detection of pollutants is, it is
quantitative detection which is crucial to EPA. This is a considerably
more difficult problem and at this time no one can say with certainty
which of the non-contact sensors presently under development will meet
this requirement. In addition to inherent limitations, a basic difficulty
non-contact sensors must overcome is the fundamental problem of atmos-
pheric interferences.
II - 168
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Several persons also noted that to justify their development
expense, future non-contact sensors will have to be good; by this
I presume they meant reliable, provide inexpensive data acquisition,
operate under extreme ranges of temperature and humidity and other
hostile ambient conditions, and yet maintain accurate calibration.
And of course, a new instrument or technique woald have to prove
itself cost-effective before it could be introduced in monitoring
systems.
One problem was highlighted during the discussion which I believe
has an important bearing on all monitoring strategy, and is not exclu-
sively that of non-contact sensors. The problem is one of knowing
just where to collect environmental data and what the frequency of
sampling should be - this point was also emphasized in one of the
informal papers. Even with the best sensor conceivable, if it is
not deployed properly the data obtained from it will have little
value to EPA. Basically, the problem is that the kinetics of
environmental dynamics is not too well understood. In the case of
the atmosphere, it was pointed out that meteorological parameters
effect our quality to a considerable extent and I think it was Dr. Bill
Davis of NOAA who indicated thai a study of millimeter radiometry of
atmospheric temperature profiles would help considerably in under-
standing the dynamics of uhe atmosphere.
In attempting to get an idea of what development costs for non-
contact sensors might be, reference was made to the ESSO report which
projected fivu ~rear development costs for atmospheric pollutant sensors
and estimated these would be auout 70 million dollars. Dr. Al Ellison
averred that development costs for a single pollutant detector would
be at least $200,000 and could easily be doubled or more. Someone
stated that Barringer has a UV correlation spectrometer for SOQ and
NO
costing $20,000 per unit.
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SENSOR PLATFORMS WORKSHOP
Pnuol A - Marine and Terrer.tria]
Panel Chairman, M. Felsher, EPA
The panel concluded that Regional and Laboratory needs in
regards to sensor platforms do cover the entire range of such
platforms as they are now available. The panel feels that all
platforms are potentially useful. In the native environment
this includes the proper use of boats to barges to buoys. It
includes stationary, mobile, and towed platforms. It includes
emplacement on the water surface, under the water surface, and
on the subshale sea or estuary bottom.
The discussion of terrestrial platforms centered mainly on the
use of mobile vans, as special event vehicles able to perform
immediate and competent analyses on a trouble-shooting basis.
Routine monitoring and complex analyses would be reserved for
established regional and national laboratory centers.
The panel felt that the Agency should contact other govern-
mental departments and seek cooperation in securing needed sensor
platforms, such as boats and land vehicles.
Availability of suitable marine platforms will depend upon
geographic necessity. Also, each Region should have enough mobile
vans or special—event laboratories to assure the acquisition and
analysis of sufficient data and dissemination of information of
such quality as it required by our Agency mission.
II - 1?0
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SENSOR PLATFORMS WORK, HOP
Panel B - Aircraft and Sp icecraft
Panel Chairman, L. Dunn EPA
SPACECRAFT
The' potential advantages of remote sensi ig from spacecraft
include global synoptic coverage of oceans ard continents with
resolution necessary to disclose large-scale pollution effects.
Th<: ability of satellit s to •t ake sequential imagery of large
areas over extended periods of time iri.ll be a very valuable tool.
These attributes make satellite sensing particularly beneficial
for monitoring in the following areas:
a) regional resource management (Forestry)
b) land use planning (sewage treatment, outfalls)
c) agricultural management (techniques)
d) documentation of long term environmental quality
e) large scale pollution effects
The primary sensors available en spacecraft are metric cameras
multispectral line scanners and microwave anc IR radiometers. The
NASA ERTS and Skylab spacecraft have a number of sensors which can
be useful for monitoring environmental quality such as above.
The disadvantage of satellite monitoring for environmental
pollutants is that most of the data acquired from space relates to
environmental quality, is a "cause-effect" tjpe, and is not pollution
specific. As a result, ac,.-"3 or passive s^rsors that can qualitate
and/or quantitate specific pollutants, with the exception of temperature,
must be developed.
AIRCRAFT
Aircraft have the specific advantage of Low altitude flight which
enables the sensors to achieve greater spatial resolution. Another
major advantage of aircraft is the ability tc carry "in situ" sensors.
Many "ii. ^i + u" real-tim- air pollutant sensors have recently become
available for monitoring. In most oases, these sensors are pollutant
specific. Examples of these sensors are:
II -371
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SO Ozone
Hg CH
-A.
NO Piezo-electric (mass per unit
x \
volume)
The NASA Earth Resources Aircraft could provide some aerial
coverage of environmental data. These aircraft include P-3A and
C-130 medium altitude aircraft, and an RB-57 and U-2 high altitude
aircraft. NOAA also is organizing an aircraft capability to respond
to National emergencies which could also be of assistance.
RECOMMENDATIONS
The regional representatives expressed a desire for the following:
a) A listing of sensors (state of the art) which are presently
available and which can be employed for environmental
quality monitoring.
b) The majority of the regional representatives were con-
cerned that tho remote sensor data produced was of little
value unless the data was analyzed. Their in-house expertise
and funding to contract for these services were very limited.
c) Because of the resources shortage within the regions at the
present time, the interpretive analysis capability should
be developed immediately within EPA. Supplemental support
should be arranged with existing facilities in other govern-
ment agencies such as NASA, USGS, and NOAA, or from industry
and universities as needed.
d) A list of sensors, aircraft, data interpretation assistance,
and scheduling from the Federal Agencies should be documented
and made available to the regional EPA offices as soon as
possible.
e) There should be more coordination between EPA and other Federal-
agencies with specialized aircraft monitoring capabilities,
such as NASA and NOAA.
f) EPA should investigate the applicability of the ERTS data
in the areas mentioned and provide scientific investigators
and monitors on select investigations concerned with
environmental studies.
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g) The use of satellites to provide a data relay capability
such as that to be provided by the NASA Earth Resources
Technology Satellite in the Spring of 1972 should be
explored. Data transmission platforms should be obtained
as soon as possible and disseminated to the regions who
have a need and are capable of attaching the appropriate
in situ sensors.
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SENSOR DAr''A MANAGEMENT WORKSHOP
Panel A - Current Data Systems
Panel Chairman, J. Reagan, EPA
The Current Data Systems I anel discussed the existing data
systems for current adequacies and deficiencies. Fxture development
may be in part guided by eliminating current defects and problems.
Although each regional office has need for good technical and
management information systems, the discussion was limited to
pollution source and environmental quality measurement systems.
Three separate areas were considered: data acquisition,
data processing (including storage and retrieval), and data usage.
Data Acquisition
Many typos of data acquisition equipment are available to data
collectors. These range from simple analog trace devices in the
hundred dollar range up to computerized acquisJtion, reduction and
analysis systems costing in excess of $50,000.
The paper by Lathrop and Jones on the use of LSI data storage
given at the Joint Conference on Sensing Environmental Pollutants
discussed some of the existing systems and their drawbacks. Cost,
usefulness and durability appear to be conflicting factors in current
acquisition systems. Electromechanical paper tape punches, though
cheap, tend to record erroneously or break dowr. Strip chart recorders
may be inexpensive but inaccurate, or accurate and expensive, as
contrasted by the Rustrak and Leeds-Northrup plotters. The authors
point out that the power requirements for most recording systems
shorten the possible unattended operating pericd using stored power.
Their parti:ular application of LSI data storage techniques to buoy
thermal sensing is promising but is limited in data storage volume to
10 bits. This is a severe limitatioi for most sensors.
IT - 174
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Sophisticated instrumentation is generallr based upon inference
procedures rather than direct measurement. Ma-ay of these instruments
pro luce vast quantities of data which must be smoothed and compared
to files of signatures for complete compound identification and
quantification. These instruments should generally have dedicated
mini-computer systems to enable the operator to rapidly acquire
and evaluate data.
Multiple instrumentation facilities such , s trailer mounted
laboratories or monitoring iacilities should h,,ve fairly sophisticated
acquisition equipment mounted in them. Simple data translators can
serv3 in lieu of multipurpose digital computer;; when rapid data
interpretation is needed. However, some instri-mentation may require
that data be manipulated in a complex manner, ~ hereby requiring
dedicated j ogic devices.
With £ view to regional coordination, mob:'.le platform facilities
should be ceveloped jointly to achieve some economy of scale and
more importantly the interchangeability of p^r-s and processes.
Regional usage may fluctuate allowing the systems to be loaned between
regions for short periods. Comparability is important to assure ease
and accuracy of operation by all personnel.
Recommend that an exhaustive survey be made of available systems,
outlining the capabilities of each anc its limitations. Further
research into data reduction techniques prior to recording should
also f , ^<=. Definition of the output data required for the end
user can allow considerate"" of the comux/iation of data integration
techniques vith data storage and identification techniques to reduce
resources eiloted to data acquisition. The subsequent costs in
computer processing and manpower must be considered in the light of
total least cost and availability of the different resources. In—
vestigatior should also be made of the applicability of declassified
communication and information system research.
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Existing systems in EPA include 3TORET and NADIS with additional
systems on oil and hazardous materials, radiation surveillance,
pesticides in air, residual soil pesticides anc human pesticide
residues, solid wastes and probably others.
The STORET system is on ar IBM 360/65 with data cell storage
provided by Boeing Computer Services. Current operating experience
is good compared to the recent past. Basic so 'tware problems have
been solved leaving only hardware failures and operating mistakes
as annoyances. Approximately 100 terminals ara now online, based in
water analysis, and use agencies around the coontry.
Data on physical and cherrri cal measurement 3 of water samples are
in STORET. Also, inventories of industrial and municipal waste sources,
implementation plan schedules and certain math modeling capacity are
part of the system.
A change in contractors providing the supporting hardware was
disastrous from the user's point-of-view. It is strongly recommended
that the disruption in service of such a change be considered an
added cost when comparing competing bids for the support service.
In no case can this disruption reoccur.
The NADIS system is based on an EPA IBM 300/50 computer located.
at the Research Triangle Park, North Carolina .'acility. Transfer of
the National Aerometric Data Bank fre m the Honeywell 4-00 in Cincinnati
and alteration of the SAROAD programs to the new computer are in process.
Concurrently, the past and current data are be: ng collected from state
and local agencies by the MITRE Corporation on contract to EPA.
Hardware limitations currently preclude the direct access of the
data base b;r regional offices. With increasing volumes of data and
data utilization requirements, direct access i:; deemed necessary in
support of regional operations.
A new data base on oil and hazardous mate "ials spills has been
established vith another contractor. Over 25 oieces of information
can be stored to describe each occurrence. Fe if of the existing terminals
can access the data base throufh the current system. The problem is due
to the nonstandard data transmission modes of \SCII vs. BCD.
II - 176
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ii addition, the Office of Radiation Programs is designing a data
. .,yt>tem for radiation data, Office of Solid Waste Programs is implementing
1'oth a data and monitoring system for solid wastes, and the Office of
Pesticides has a data ba;.e on soil residues and is designing one for
human tissue residues and air concentrations.
Recommend that the proliferation of data systems stop and that
existing systems be coordinated. This coordination is important to
facilitate correlative work that will be carried on. Accessibility
should be improved along with operating details. Coordination with
other agencies is vital. Contact should be established at the highest
level with communication channels established at the operating level.
These contacts should include NOAA for oceanographic and atmospheric
data and NASA for ERTS and other programs. Technical Coordination
Papers in eight areas including oil, ships, radiation, the Navy
Environmental Protection Data Base and other are due to the Pentagon
for review by mid December. The EPA should coordinate activities with
the Navy in these common areas of interest.
Data Usage
Usage and manipulative capabilities in the Regional Offices are
limited to the capabilities offered by programable calculators and
some simple math modeling capability in the STORET system. The
development of laboratory capabilities in the Regional Offices should
be accompanied by the development of a data processing capability.
Data processing techniques are being centralized within the
Mans.^™--^, Division of most, if not all, Regional Offices. Coordination
of Regional developments should bQ r^--.—^ to achieve interchange of
techniques. The development of this capability is directly associated
with the selection and acquisition of the data handling equipment for
the entire agency.
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Data Reliability
Both the air and water data bases have been characterized as
very large sources of data of questionable reliability. Some data
is very good, but some is terrible. Nonstandard and unequivalent
sampling locations, frequencies, methods and procedures hamper the
large scale integration of previous environmental measurements.
Reliability judgements are largely subjective and may vary between
persons. The development of standard, reliable methods is again
restressed here as it has been in other conferences and panels.
II - 1?8
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SENSOR DATA MANAGEMENT WORKSHOP
Panel B - Future Data Systems
Panel Chairman, E. Grennin;;, EPA
BACKGROUND
It is helpfal to establish a rational frame of reference within
which a future environmental quality data management system must
function effectively. Figure 1 presents a simple block diagram
showing where the data management system fits in a conceptualization
of the overall environmental monitoring operation.
Knvironmental quality data are acquired by various sensors
(contact, non-contact, biological) transmitted, analyzed, stored and
retrieved by the data management system which produces information
needed by the four indicated functions, enforcement; state of environ-
ment; research and environmental planning. The four functions are not
independent, research having some input to all of them and enforcement
and planning providing a direct feedback to environmental quality.
At any point in time the hardware and software configuration of the
data management system will be determined by its interfaces with the
overall monitoring operation, i.e., by the raw data acquired by the
sensors and the informa1' >n output required by each of the four functions.
As information requirements and sensor technology and concepts
chcii1',^ with time the data management subsystem configuration will evolve
in response ^o thuoC needs and will, to some degree, influence the
evolution of those needs, o.^. initial configuration of the data
management subsystem consists of all of the EPA and non-EPA environmental
quality data management systems currently in operation.
FUTURE DATA MANAGEMENT SYSTEM
What kind of data management system configuration should be estab-
lished? It was the consensus of the panel that a traditional pyramid
type of infrastructure Containing loca; state; regional and national
Bevels would b--, ?.p, ro-pr-iate. Figure 2 yrc^ents a simple schematic of
thi;; concept. Information flows upward in the infrastructure with
env'ronmr*-'; <"!. -Considerations and coyroLipo.iCL^, data requirements
becoming increasingly sj/noptic in moving from the local to the
r- i ' ievfl,
II ,7 179 '
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Data could be acquired independently at each level and combined
with data from the next lower level to obtain a needed measurement
of environmental quality. For example, a region could independently
contract for an aerial survey of its territory and use in-situ data
obtained from the states for ground truth corroboration of remote
sensing imagery.
Some doubt was expressed concerning the usefulness of environ-
mental situation centerr, at the regional and national levels mostly
because of the time lag between pollution detection by monitoring
and correction through enforcement. However, a need for regional and
national episode centers incorporating modern data management and
display techniques aimed at monitoring and possibly controlling short
lived environmental phenomena such as air pollution episodes, oil
spills toxic substance releases, forest fires, etc., was recognized.
The practical impossibility of perpetual storage of all acquired
data was recognized and possible criteria for data destruction discussed.
In general the duration of storage of a particular datum is approximately
porportional to the spatial or temporal scale of.the phenomena the
datum represents. Accordingly, a possible mode of data destruction
starting with an hourly average; of some parameler would be to regress
to a daily average in the first year; daily to monthly the next year;
monthly to semi-annually; semi-annually to annually and then annually
to destruction.
This would result in stepwise data destruction while tending to
maintain longer duration temporal averages germane to synoptic
environmental considerations. Data representing some large spatial
scale environmental phenomena might be stored perpetually, e.g., the
annual average temperature of the earths atmosphere at sea level.
ESTABLISHMENT OF FUTURE DATA MANAGEMENT SYSTEM
It was agreed by the panel that the data, statistics and/or
indicies required to best serve the purposes of the four information
use functions indicated in Figure 1 must first be carefully defined
II - 180
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sine ^ they iiri.ll be a strong determinant of data management
system hard/are and software configuration. Having specified infor-
mation requirements a reasonable next step wor .d be the combination
of all existing EPA data management : ystems (e.g., STORET, NADIS,
pesticides and radiation.) into a si.igle comprehensive system capable
of partially satisfying the informat on requir sments . In parallel a
survey of existing non-EPA environmental data nanagei.ient systems
should be performed with all useful systems being apif the system consisting
of f xistin-:; EPA networks as well as networks p aced in the field to
fi!3 gaps in the national monitoring system. i|Vurthermore, there is
monitoring being performed by other agencies t lat th<- panel believed
should be >roperly conducted by EPA, e.g., the water quality monitoring
conducted >y the USGS on the basis of an agree nent made with FWQA three
/ears prior to the formation of EPA. However, there was also unanimous
agreement that development of a national emr"ionmental monitoring
system mus". be pursued in a cooperative rather than competitive spirit
in spite o;1? t -1 ^re budgetary constraints.
II - 1 51
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o
g
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to
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i: - 182
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ATIONA1
Independent source
of data
REGIONAL
STATE
LOCAL
Other Regions
DATA MANAGEMENT INFRASTRUCTURE
FIGURE 2
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SENSOR TRIORI'i'IES WORKSHOP
Panel A - Short Teru Panel (]-5 yea.'s)
Panel Chairman C. Weber, EPA
Short term sensors, platforms and data management needs in
ea.'h of the specific monitoring areas are as follows:
NQ]SE
Current sensors and xLatforms for measuring general ambient
(background) noise are a^ equate. There is a reed for a valid
universal scale on which to express noise fron all sources. Ways
must be explored to measure the effects of noi se on human welfare -
such as the possible physical and psychologic^1 effects, and
optimum noise levels. Methods must be develojed to determine the
public reaction to noise - such as personal ii terviews, and to
col]°ct and channel piblic complaints to a (central) office which
can evaluate and act en the complaints.
AIR
The air pollutants of principle interest ire SO , NO , OX, HC
.X X.
and particu ates. No operational automatic f33ld sensors are
available for these pollutants but sensors foi SO and NO are
xx
currently under evaluation and should be oper; tional in the near
future. Sensors shou]i be developed for the ether principal
pollutajts to monitor emissions and ambient aJr quality. Use of
aircraft- to provide real-time data on air qv i] ity should be given
greater attention. As with noise, methods of neasuring low grade
effects on hi. e health and welfare should be ieveloped. More effort
should be expen^'-1 in shortening the time betvsen sample collection,
analysis and r-ita evaluation.
WATER
Thus are;-, has the .Largest number of oper; oional "in situ" sensors
availal le for tield work. The parameters mea; jred include temperature,
conduc iv.-ty, oH, dissol red ox/gen, dissolved chlorides, oxidation-
reduction f rte-rtial and ourbid ty, listed in i le order of their
reliability. lion-contact remote measurement ( u surface temperature
-------
by R-scan iers is in an advance-i stape t^ .veLopmenb, chlorophyll
mea .uremeni, by air or spaceborne spei trometry ind laser activated
flu ircscenoe shows promise and should be prrfe :ted.
IN- '.ITU
Sense -s are also under development for pi snols and oxygen decay
(ox/gen demand). Ion or compound specific sei sors should be developed
for dissolved bound nitrogen, total phosphoru: and other macronutrients
and specific pollutants.
Fouling and other problems requiring fre uent maintenance of in
sit i sensors are serious problems affecting t.ie cost and reliability
of the data; high priority should be given to the development of
anti-fouling devices and increasing sensor reliability.
SOLID WASTE
Aircraft and space platforms should be used to determine land
utilization for solid waste disposal, optimize waste disposal practices
and determine geographical distribution of solid waste disposal burdens.
Methods must be developed to quantify the solid waste burden on a
national scale, and to provide real-^i.^e data on trends in the waste
burden and chemical composition. Enviro imentc1 effects of land
fills - such as seepage of microbiological pollutants into ground
and surface waters, and the effect of seepage and gaseous emissions
on adjacent vegetation and annual life. Inci) erator emissions should
be rronitored. Much of the technology develops d or in use by the air
and -rater pollution control programs is applicable to monitoring solid
wast; disposal activities.
PESTICIDES
Monitoring programs for pesticiles a_n aii, soil and water should
be more c." " 1y coordinated, and completely ir tegrated, if possible.
Techiiiques I.-, no i-contact passive or active tensing of pesticides on
the soil s rface .should be: investigated, usin/ UV or other appropriate
regions of -he EM sp' jtrum. Efforts should be made to reduce the time
between sami le coll jtion, analysis and data evaluation.
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RADIOACTIVITY
Environmental levels of I ritium and nobli gases should be monitorea
Current ambient levels of tril ium activity ar< too low to measure "in
situ" with present equipment, ma me ,hods of sotope enrichment should
be developed.
GENERAL RECOMMENDATIONS
1. Level of monitoring activity in all area; should be sub-
stantially increased by allocation of adcitional funds and
positions.
2. Need to present informati m on jnvironrnei tal quality to the
publit on a regular basis - to provide v:' sibility for the
monitc ring program, increase public awar< ness of the program,
make environmental data u ;eful to the pullic, and £ain
additional legislative si >port.
3. Courses on sensor use in Lhe EPA program should be included
in the Agency Training Program.
4- The Agency needs a program of instrument certification to aid
industry, state and local governments ^n acquiring instruments
to meet effluent (emission) sta-idards.
5. Telemetry of data from sensor platforms A La stationary satellite
to an EPA ground receiving station could Deduce overall cost and
increase efficiency of data collection bj the central data
handling system.
6. Methods of data redu :tion (integration) et the sensor platform
shoulc be developed >o reduce t le volume of data transmitted to
the central data collection facility.
7- Participation in the global monitoring program.
8. Coordinate ™ bh other federal agencies In acquiring existing
imagery and o "er da-a, and in collecting new d ita.
9. Broader re '.onsl sur oillance programs to inclu ie environmental
parameters not now r j_ng measured, and to utilize aircraft,
spacecraft and othe, available capabilities in identifying pollution
sources, determining station location, pi inning and executing their
programs.
I". - U-6
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10. Nc< d bettor 'indices of em irorim -rital pol ution and better
predictive models.
11. Data storage, retrieval aid evaluation systems should be
consolidated and standardized ( jnvironrnei tal data are now
stored in several facilities ui ing non-s" andard hardware
and telecommunications cedes).
12. Policies should be established for data >athwaj3, summarization
and storage periods.
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SENSOR PRIORITIES WORKHOP
Panel B - Long Term Panel (5-15 years)
Panel Chairman, A. Ellisci, EPA
The long-term priorities panel took the position that prior to
15 years from now environmental management systems vould be in
effect. This would mean that major sources oi pollution would be
sited and consolidated so that their influence could be controlled
and have a minimum impact on environnental quality. Such planning
would incl ide the system of monitori ig these tources and the
surrounding area.
With this basic premise in mind, the panel went on to delineate
specific long-term monitoring and/or sensor needs. The panel agreed
that real time monitoring of precipitation woiId be needed. By this
means, it would be possible to determine impoi tant environmental
transport mechanisms. It was recommended ' haj EPA become involved
in global atmospheric monitoring and that thr effort be coordinated
with the efforts of other government agencies involved in global
monitoring. It was pointed out that the tech: ology of remote sensing
of the earth's surface by multiband photography was moving ahead
rapidly and that the utilization of this data by EPA would require
work to develop more rapid data interpretatioi. systems.
It was felt that personal dosimeters for selected pollutants
should be ceveloped. These would be used by opulation groups who
might be exposed to certain pollutants becau,. of the proximity of
a source st?h \s a jower plant, highway, etc.
Remote sensc^ -. Tor pesticides are needed. It is believed that
the use of pesticides will increase in the coming years. The pesticides
used will te different th n those used now and will include herbicides.
It will be necessary to jonitor these materials to determine their
persistence in the atmosphere, t-heir effects o i people i.nd/or things
and their chemical degradation. It woijld be desirable to label pesti-
cidas and tc de\jlop appropriate sensors so th ,t the transport of
pes^ici ; throv a;h ecological cycles could be 'ollowed.
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The U5>' of satellites as i elay stations for environmental
monitoring data was discussed. Systems are n'.w available which can
transmit sensor signals to a s; oellite which relays the data back
to a central earth station for rapid processing and display. We
should therefore consider a geostationary EPA satellite to provide
such a communications link witi a central EPA station.
It was pointed ou~' that s vratospheric raoritoring is needed. Such
monitoring will r^equi a new te ^hniques for paroiculate matter, humidity,
and rther potential pollutants from civilian cr military stratospheric
airrraft. Also there is a nee i to establish tie background of atmos-
pheric aerosol. Such material has an effect 01 radio communications
and it is necessary to know whether this background is increasing or
decreasing.
Multipollutant air sensors based on semiconductors coated with
pollutant specific layers and multipollutant vater sensors based on
ion specific electrodes should be explored. la this regard it was
pointed out that acoustic sounding may se. ve as a single measurement
for many meteorological parameters. If nee led, these multiparameter
or multipollutant detectors coald probably be available earlier than
5 years from now.
Finally it was pointed ov.t that many of the government agencies
involved in the collection of environmental dita are using incompatible
data systems. As soon as possible, these shoild be made compatible
so that the cross utilization of data obtainec by various agencies
will be simple and stra ghtfor-\rard.
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PART II
G. Closing Remarks
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CLOSING REMARKS
B?lbert S. Earth
Director
National Em< .ronmental Rese .rch Center
Researc i Triangle Park N. C.
There are a couple of tl ings I would li :e to say. One is, ±
appreciate the opportunity tc be involved wi ,h this entire meeting,
greatly appreciate the opportunity of meeting all of the people who
:ame here, particularly those in the regions I would like to
convey just one though o to ycj. and that is what the EPA was really
created to do. President Nixon in his message setting up the EPA
commented and strongly emphas .zed the fact t lat the creation of
this agency would enable us to deve op a coo "dinated attack on the
t< tal problems of environmental pollution. "n order to do this,
cl ?arly we have to develop a coordinated env .ronmental monitoring
sj stein. We are no/or going 1 o get ther^ iint .1 we get to know one
Brother and find cut exactly where ve are no- 7. We have to determine
whsre our smarting point is.
That means we have to gc b to know one another, the people who
have been in air and know thf air program ha^re to find out about
the water program and the wa1 sr people have to find out about the
air and all the other things, solid wastes, radiation, pesticides.
A meeting like this goes a long way towards getting at least a
start in that direction. I hope that the stfrts that have been made here
will be built on in the future and In fact v will be able to develop
a coordinated and integrated monitoring prog "am. In so far as the
National Envii . .tal Reseai :h Center at th . Research Triangle Park
is conce -ned, I L. -sure all oi you in the var -Ous regions that we
will do )ur -,"• < y b jst to . el] you in any way that we can through
the prov sion of techrr al ac /ice, consultation, technical services,
and in g( neral to do oar ver^ best to help you in our areas of expertise.
In my owr jud^-ient I think tl 3 biggest need we have in this program
is the o] :i irobJ em of develop ing the environmental monitoring system
- 190
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to be an integrated one. We can not continu3 to proliferate more
and more measurements for more and more deteiled pollutants at
more and more stations throughout one entire U.S. We have got
to do a better job at developing more efficiant systems. To do
this ue need indices of total environmental pollution. We need
to develop monitoring systems where we can £3t the daoa we need
for air, water, solid waste, radiation, pesticides in some kind of
efficient pattern, and not with a continued proliferation of more
and more stations and more and more location 3 to sample for
individual pollutants. That would be a neve" ending process which
becomes extremely expensive. Certainly in tiaes when we do not
have enough funds, it has to be one of the directions in which
we must move. The second thing I think we n^ed, and of most
importance, is better predictive mi-dels. Th5 better our models
ai e the 'ewer number of points we have to sanple at in order to
d( terrain what the environmental qi ality is. So t lese are the two
b: g things that I see that are neeced lr thia entire area.
II - 191
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CLOSING REMARKS
John McBride
Deputj Directoi
Western Environmental Research Laboratory
Las Veft-as, Nevaca
On behalf of the V stern Envi -onmental Research Laboratory we
are very pleased to b re you here -ind hope i hat the meeting rooms
that you had were con/enient, comfortable ar.d thai, the other
accommodations w> re adequate . I would like to coriiment on the
meeting itself.
From reports given to r. ), I was told tl at in several of the
meetings the lack of funds c *• requirements or more funds came up.
I would like to leave you wijh a slightly controversial note and
say that maybe this is a blessing in disgui ;e for all of us.
Because in one way it makes is look to each other to see how we can
get the help that Jon Holmet was talkiej ab ut. It makes us look
to other agencies to see how we can get their help, and I think
tLat once we get outselves coordinated thei. we can take better
advantage of the funds that ire given us.
Thank you.
- 192
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3 ART II
H. Appendices
A. News Release-
B. Roster of Participants
C. Glossary of Terms
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NEV.3 RELEASE
ENVIRONMENTAL N^WS
ENVIRONMENTAL PROTECTION AGENCY
Western Environmental Research Laboratory
P.O. Box 15027 Las Vegao, Nevada 89114
WEfL-1871 G.S.Douglas 736-2969
December 1, 1971
FOI IMMEDIATE RE.EASE
Fifty-five people fr< m the U. S. Environmental Protection
Agtncy (EPA), from other Fede -al agencies and from Jniversities are in
La; Vegas for an Environmenta Quality Sensor "Works lop November 30
through Daeember 2 being hosted by the EPA's Western Environmental
Research Laboratory.
This meeting is to bring together fiose responsible for
monitorin envircrjnental quality to ei^.^e in a free exchange of ideas
and to learn firsthand about the monitoring activities and requirements
of the ten EPA Regions," said Willie B. Fo/te-, EPA's Deputy Assistant
Admxnistrc- tor for Monitoring. His Office is .sponsoring the Workshop.
' Monitoring the environment is a key to effective management
for enviri nmental quality," said Donald C. Ho.'jnes, Director of EPA's
Monitoring Techniques Division, and Chairman of the Workshop. "It is
nearly impossible to detect environmental changes, desirable or undesirable,
natural or man-made, without established ba°e lines and repeated observations."
Measuremerts are essential for the identif- cabion of environmental needs and
the establir"unent of program priorities, as wall a9 for the evaluation of
program effec i ^aess. He added that monitoring also provides "an early
warning system x jr environmental problems whi:h allows corrective action
to be taken.!i
The EPA's pr .ary mission .s setting environmental pollution
standards, regulation, and enforcement to achieve environmental quality.
"Only through a reliable, efficient and timel/ monitoring program based
on the Tract advanced concepts in sensor techn
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Pa^e 2 - WERL-1871
to meet the challenge of creating and main4'ailing a healthful environment
for present and future g\ ".ei\;.t Ions," Foster f aid.
Oi r-u^sday morning, ]>. Deloert S. - arth, arector of the
National Emn reimen-jl Rf searci Center at Ressarch ' riangle Park, North
Carolina, discussed moni Coring needs for air oollut -on and systems
reauired tc meet th ^ meds. Dr. S. Q. Dunt Ley, Director of the
Visibility LaboraJ ; at Scrijps Oceanographi: Institute presented
opt .cal methods ~oc detection of water pollut .on, and Dr. L. W. Bowden,
Geo. o~y Department Ch j-iman a~ the University of California-Riverside,
spoke on emote sensing of en ironmental qual_ty in relation to land
management.
Following a tour 01 the Western Environmental Research
Laboratory's special monitoring and sampling Arcraft at McCarran Airport,
workshcp attendees heard Dr. F. Alt;.hulj.er of EPA discuss analytical
problems in air pollution control, ?ind Mrs. Elizabeth Cuadra, EPA's
Deputy Direct ~j_ for Program Develop iti. , Office of Noise Abatement and
Control, discuss the state-of-the-art ir nois-; monitoring.
)n Tuesday, Mr. William Savers jf EPi's Office of Monitoring
vn. 1 spea on approaches to wtter qualloy mon .toring, and Mr. Harry Stierli
of the Na ional Environmental Research Center-Cincinnati will speak on
in situ ai d remote sensing fo' solid wastes. Mr. Vernon Andrews, Deputy
Chief of ha WERL's Environme tal Surveillance Program, will present a
current r ^ ow of radiation s nsing, and Dr. J. Wiersma of the EPA's
Office of Pest-" :des Program 111 spsak r seiso^- data management for
monitoring pest.'.cides and rel t,ed co-npou ds. Several panel discussions
and specj. """shops will be held throughouc the meeting which ends on
Thursday, : -iorkshop will c lose with a gui led to ir of the Western
Er Yiron.'c . s . ^search laboratory's facilities in Las Vegas.
A-2
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APPEND]\ B - ATTEK " TSS
Dr. A. P. Altshuller, Director
Division of Chemistry & ?hysi< s
National Environmental Research Center
Environmental Protection Agency
Research Triangle Park, NO 27711
Ve non Andrews
We ;tern Environmental Research Laboratory
En/ironmertal Protection Agency
P. 0. Box 15027
Las Vegas, NV 89114
Homer Aschmann
Professor of Geography
UiiLversity of California
Riverside, CA 92502
Dr. Delbert S. Barth, Director
National Environmental Research Center
En dronmental Protection Agency
Re ;earch Triangle Park, NC 27711
Wi liam J. Basbf gill
Su.iv. Chemist
Division of Surveillance and Analysis
Region VI I
1860 Lincoln Street
Denver, Colorado 80203
Dr. Donal'i Baumgartner, Chief
National toasta"- Pollution Research Program
National frivironmental Research Center
Environmental Protection Agency
200 S.W. '5th Screet
Corvallis OR 97330
Dr. Leonard W. Bowden
Associate Proj. , 5 T
Departmen : of Ge -• -aphy
Uni versit,r of Cal. i'ornia
Rii-erside CA 2502
Robert J. Bowden
Chief, Surveillance Brr.ich
Environmental Protection Agency, Region V
1 North Wecker Drive
Chicago, !_, 60606
B-l
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A" bert Bromberg
C'iief, Operational Branch
Surveillance and Analys:i s Div Lsion
Environmental Protection Agency, Region II
Edison, NJ 0331?
D. H. Bundy
Western Environmental Researcn Laboratory
Environmental Protection Agency
P. 0. Box 1502?
".as Vegas, NV 89114
John W. Cain
Technical Advisor to Directoi
National Photo Interpretatior Center
6012 Craft Road
Alexandria, VA 22310
Dr. Paul Craig
Research Applications (Advanced Technology)
National Science Foundation
1800 G Street, N.W.
Washington, D.C. 20550
Mr,;. ^lizabeth Cueira
Deputy Director for Program I avelopraent
Office of Noise Abatement anc Control
Environmental Protection Ager cy
1835 K Street, N.W.
Washingto-i, D.C. 20460
Dr. William 0. Davis
Chief, Research Applications
Office of Environmental Monitoring and Prediction
NOAA
Rockville, MD 20852
Hans Dolezalek
Office of Naval Research
Code 412
Arlington, VA .- ' 7
Leslie Dunn
Western Envir -njnbal Researc i Laboratory
Environmental l rotectior Agency
P. D. Box 15027
Las Vegas, NV O109
3-2
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S. Q. Duntley
Professor
Scripps Institution of Oceanography
University of California, Sa ' Diego
La Jolla, CA 92037
Dr. A. H. Ellison
Assistant Director
Di/ision of Chemistry and Physics
Technical Center, Room Q304
National Environmental Research Center
Environmental Protection Agency
Research Triangle Park, NC 2 711
Dr. Murray Felsher
Senior Staff Geologist
Office of Technical Analysis
Office of Enforcement and General Counsel
Environmental Protection Agei cy
Washington, D.C. 20460
Dr. E. T. Florance
Theoretical Physicist
Office of Naval Research
1030 E. Green Street
Pasadena, CA 91106
Mr. Willis B. Foster
Deputy Assistant Administrator for Monitoring
Environmental Protection Agercy
Washington, D.C. 20460
Edward M. Grenning
Monitoring Analysis Division
Office of Research and Monitc ring
Environmental Protection Ager cy
Washington, D.C. 20460
John E. Hagan, Chief
Pollution Control Systems & Analysis Branch
Division :>f , , . eillanco and Analysis
Southeast Wate, aboratory
Environmental Pi Section Agen-y, Region IV
College Stat' ^ Road
Athens, GA 3^01
George Harlow
Chief, Enforcement Branch
Region IV
Ervironmurtal Protection Ager :y
1121 Peach-ree Street, N.E.
AtLan , GA 30309
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Donald C. Holmes, Director
Monitoring Techniques Division
Office of Research and Monitoring
Environmental Protection Agency
Washington, D.C. 20460
Robert F. Holmes
Sensor Program Officer
Office of Research and Monitoring
Environmental Protection Agency
Washington, D.C. 2046")
Mr. David R. Hopkir
Technical Director
Lower Florida Estuary Study
Environmental Protection Agency, Region IV
P. 0. Box 22268
Ft. Lauderdale, FL 33315
Charles R. Hosier
Chief, ^rogram Off- ce
Divisio-i of Meteor )logy
National Environmental Research Certer
Environmental Prot"ction Agency
Re search Triangle 'ark, NC 27711
C. Eugene James
Air Force Consultai-ts Register
9300 Brink Road
Gaithersburg, MD 2C?60
J. W. Jarman
Corps 01" Engineers
Forrestal Building. Rm 4G040
Washington, BSC. ; 0314
Malcolm F. KaLlus
Director, Houston lacility
Environmental Protection Agency, Region VI
3801 Kirby Drive, Juite 738
Houston, TX 77006
Mj ron Kn idson
Chief, S .rve? llc.nce Branch
Surveillance and Aralys~",3 Division
En /ironm< nta.-. Prote cti .1 Agency, Region I
21,0 High! ana Avenue
Nesdham : eights, M/ J2194
Joan D. SoutjandrecS
Chief, tensor Brancn
Monitorin Tecnniques Division
Offie cf Research and Monitoring
Eivi_-onrr ental Protection Agency
Washington, D.C. 20460
B—4
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Daniel F. Krawczyk, Chief
Co'isolidated Lab Services
National Environmental Research Center
Emironmental Protection Agency
200 S. ¥. 35th Street
Corvallis, OR 97330
James 0. Lee, Jr.
Head, Ecological Investigations
Animal Plant Health Service
TTSDA
federal Center Buildirg, Rm 437
Hyattsville, MD
Dr. Allen S. Lefohn
Office of Research and Monitc "ing
irviroi mental Protection Ager :y
Washington, B.C. 20460
1homas J. Lemmons
Electronics Engineer
]ivision of Meteorology
National Environmental Research Center
Environmental Protection Ager :y
Research Triangle Park, NC 27711
Dr. James R. McNesby
National Bureau of Standards
13308 Valley Drive
Rockville, MD 20850
Dr. W. A. Menzel
Consultant
Environmental Protection Agen -y, OWP
Washington, D.C. 20460
Dale B. Parke
Envj ronmental Protection Agen y, Region VII
911 Walnut Street, Room 702
Kansas City, I-'° 64106
Marshall L. Payu,-
Chief, Surveillanc ^ Branch
Environmental • Detection Agency, Region VIII
Lincoln Tower „. ilding, F ite 900
Id60 Lincoln Sc/ieet
Denver, CO 8020.
James A. Reagai , Chief
Air Quality Information Syster. 3 Branch
National Em .ronaental Resear, i Center
Environr- i-oa. Protection Agenc r
Resear-r^ Triangle Park, NC 277,1
3-5
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John Riley
Office of Research
Technology Division
Environmental Protection Agency
1901 N. Ft. Myer Drive
Arlington, VA 20460
Ronald H. Sandwina
Director, Technical Services
OSA/OCD Region Seven
Federal Regional- Centf .-
Santa Rose, CA 9540s
William T. Saye -s
Cnief, Support 3ranch
D: vision of Coo ~dinati< i and Support
Office Q-' Research and tonitoring
Environm ntal Protection Agency
Washingt n, D.C. 20460
William . Schmidt
Environmental Protection Agency, k
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Louis Swaby
Office of Re: earch and Monit< ring
Environmental Protection Agei cy
Washington, U.C. 20460
Dr. Han Tai
Supervising Chemid:.
Pesticides Regulation Divisica
Environmental Protection Agency
P. 0. Box 989
Gulfport, MS 39501
Christopher M. Tir i
Supervisory Sanitary Engineer
Enforcement Division
Environmental Protection Agency, Region VIII
I860 Lincoln Street, Suite 900
Denver, CO 80203
S. Sidney Verner
Standard Methods Program Off i cer
Office of Research and Monitoring
Environmental Protection Agency
Washington, D.C. 20460
Carl M. Walter
Environmental Protection Age cy, Region VII
911 Walnut
Kansas City, MO 64108
Cornelius Weber
AQCL
National Environmental Resea -ch Center
Environmental Protection Age cy
Cincinnati, OH 45268
Sidney L. Whitley
Chief, Data Acq. and Mgmt. G 'oup
Earth Rescarces Laboratory
NASA-Mississippi Test Facili y
Bay St. Louis, MS 39466
Bruce \I -»~ -ma
Ecologis, nitoring Prograns
Pesticides • ^gulation
Eivironmrr, ,0.1 Protection Ager^y
Washing!,*- D.C. 20460
Robert G. Wills
Physical Jcience^ Administrator
Surveillance and Analysis Division
Env:ronmental Protection Age icy, Region IX
620 Central Avenue, Building 2C
Alrmev a, CA 94501
B-?
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APPENDIX C
GLOSSARY OF TERMS
NERC
ERTS
GOES
EOS
ONR
MTF
RANN
NOAA
LSI
Stc: ret
NADIS
SAROAD
WKRL
OCD
RAI'S
National Env ronmental Research Ctnter
Earth ,esoui -es Technology Satellite
Geosoationar;/ Operational Er vironmental Satellite
Earth Observatory Satellite
Office of Na ral Research
Mississippi Pest Facility, Bay St. Louis, Mississippi
Research Applied t) National Needs
National Oce inic and Atraosph -ric Administration
Large Scale integration
Water Quality Control Information Storage
and Retrieval Systems
National Aeromatic Data Inf c rraatiou Service
Storage and Retrieval of Aeiametri'' Data
Western Envi ronmeni-al Research Laboratory
Office of GJ /il Defense
Regional Aii Pollution Stur
Continuous i- Lr Mon3_toring Projects
C-l
'• 'I 60604-3590 *
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