United States/Canada
Air Quality
Agreement
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GOVERNMENT OF
THE UNITED STATES OF AMERICA
AND GOVERNMENT OF CANADA
President Bush and Prime Minister Mulroney
sign the U.S.-Canada Air Quality Agreement on March 13,1991.
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United States/Canada
Air Quality Agreement
PROGRESS REPORT
March 1992
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Table of Contents
Executive Summary 1
Preface 5
SECTION I
Introduction 7
History of the Agreement 7
The Air Quality Committee: Current Activities 9
SECTION H
Progress: Specific Programs and Objectives 11
Overview 11
Sulphur Dioxide 12
Nitrogen Oxides 19
Compliance Monitoring 22
Prevention of Significant Deterioration and Visibility Protection 23
SECTION IE
Progress: Scientific and Technical Activities
and Economic Research 27
Overview 27
Emission Inventories 28
Atmospheric Modeling 29
Deposition and Air Concentration Monitoring Networks and Results 34
Effects Research and Monitoring 40
Aquatics 40
Forests 45
Materials and Cultural Resources 50
Human Health 52
Quality Assurance 54
Control Technologies 55
Market-Based Mechanisms 57
SECTION IV
Conclusion 59
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APPENDIX A
United States-Canada Air Quality Committee 61
Canadian Members 61
U.S. Members 61
Subcommittee on Program Monitoring and Reporting 62
Subcommittee on Scientific Cooperation 62
Terms of Reference
U.S.-Canada Air Quality Committee—Terms of Reference 63
Subcommittee on Program Monitoring and Reporting—Terms of Reference . . .64
Subcommittee on Scientific Cooperation—Terms of Reference 65
APPENDIX B
Agreement between the Government of the United States of America
and the Government of Canada on Air Quality 67
Annex 1 74
Annex 2 77
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Executive Summary
The Canada-United States Air
Quality Agreement, signed
March 13, 1991, marked a new
era of cooperation aimed at help-
ing to guarantee cleaner air and a healthier
environment for millions of Canadians and
Americans. The signatures of the Canadian
Prime Minister and the American Presi-
dent served to underline its significance.
Now, one year later, progress has been
made by each country, individually and
together. A forum for discussion has been
established; programs to resolve domestic
and transboundary air quality issues are
being developed, and information about
them is being shared; lessons learned from
existing and past programs also are being
shared; and the pursuit of data compatibil-
ity between countries is under way.
THE AIR QUALITY COMMITTEE
A Canada-US. Air Quality Committee
and two working subcommittees were cre-
ated in 1991. One subcommittee oversees the
implementation of the Agreement and
works on, among other things, emission
inventories, control technologies, and mar-
ket-based mechanisms. The second
subcommittee focuses on scientific and tech-
nical activities, including atmospheric and
effects research and monitoring. The com-
mittee and the two subcommittees met in
1991, and more meetings are planned for
1992. The subcommittees will meet on a
regular basis to exchange information and
initiate the programs called for in the
Agreement.
The United States and Canada are shar-
ing information on the implementation of
their respective control programs, including
the use of market-based control mecha-
nisms in the United States to achieve
more cost-effective emissions reductions.
Sulphur Dioxide Emission
Reduction Goals and Program
Canada has committed to reduce sul-
phur dioxide (SOa) emissions by 40
percent from 1980 levels in the seven east-
ernmost provinces to 2.3 million tonnes (1
tonne is equal to 1.1 tons) by 1994. About
80 percent of these reductions are now in
place. A permanent national cap also has
been set for sulphur dioxide emissions at
3.2 million tonnes by the year 2000.
Specific milestones achieved in 1991
include:
m A commitment by New Brunswick
and Ontario utilities to equip nearly
1,800 megawatts of power plant ca-
pacity with wet limestone scrubbers.
ffi The completion of major new facili-
ties at Canadian smelters notably at
Rouen Noranda, Quebec, and at
Timmins, Ontario, which has led to
more efficient capture of sulphur di-
oxide as sulphuric acid for resale.
m Construction and testing of new
power plant combustion and emis-
sion control technologies at sites in
Nova Scotia and Saskatchewan.
a The beginning of work between the
federal and provincial governments
towards the development of agree-
ments for the year 2000 national cap.
The United States is committed to re-
ducing annual SC*2 emissions by about 10
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million tons by the year 2000 and to
achieving a permanent national cap of 8.95
million tons of sulphur dioxide per year
for electric utilities by 2010. For the United
States, this is about a 40 percent reduction
in emissions from 1980 levels. The emis-
sions reductions required by the U.S.
control program begin on January 1,1995.
Phase I of the control program, which runs
through 1999, will contribute to annual re-
ductions in SQz from 1980 levels of
approximately 5 million tons. Finally, annual
industrial emissions of sulphur dioxide in
the United States are not to exceed 5.6 mil-
lion tons.
In 1991, the United States promulgated
final rules on the auction and direct sale of
SO2 emission allowances and proposed
rules in four areas of critical importance to
the acid rain program: sulphur dioxide al-
lowances, acid rain permits, continuous
emissions monitoring, and excess emis-
sions. The United States is in the process of
developing the remaining rules to imple-
ment the acid rain control program.
Nitrogen Oxides Programs
Both countries are seeking to reduce ni-
trogen oxides (NOx) emissions from both
stationary (e.g., power plants) and mobile
(e.g., passenger cars) sources.
In Canada, the commitment is to reduce
NOx emissions at stationary sources by
100,000 tonnes from a forecasted emission
level of 970,000 tonnes in the year 2000.
Measures to achieve these reductions are
being developed and implemented under
Canada's National Management Plan for
controlling NOx and VOC emissions that
cause smog.
In the United States, a NOx control pro-
gram is being implemented to reduce total
annual emissions of NOx by about 2 mil-
lion tons from 1980 levels. Rules are being
developed to reduce NOx emissions from
power plants and additional sources subject
to the ozone non-attainment provisions of
the Clean Air Act
Both countries are tightening automo-
bile NOx emissions standards. In the
United States, regulations implementing
tighter standards for passenger cars were
promulgated in June 1991, to take effect
beginning in the 1994 model year. In Can-
ada, Transport Canada announced in
February 1992 a formal agreement with
major automobile manufacturers on vol-
untary compliance with standards for
passenger cars. The agreement provides
for a phase-in of equivalent standards in
the same time frame as that required by
the U.S. Clean Air Act.
Scientific and Technical Cooperation
In this report, the two countries focused
primarily on scientific and technical activi-
ties related to acidic deposition including:
* Emission inventories: the coordina-
tion of emission inventory develop-
ment relative to sulphur dioxide and
nitrogen oxides for 1980, 1985, and
1990 (preliminary) are included.
• Atmospheric modeling: cooperation
between the two countries regarding
atmospheric model application, evalu-
ation, and development is described.
Historical and projected deposition
levels, including levels assuming full
implementation of the Canadian and
U.S. acid rain control programs are
included.
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a Deposition monitoring: the monitor-
ing of wet and dry deposition of sul-
phur and nitrogen compounds is
carried out by federal, provincial,
state, and private sector groups.
Maps of deposition levels and trends
information are included.
a Effects research and monitoring: the ef-
fects of acidic deposition on lakes
and streams, forests, materials, and
human health are discussed. Effects
monitoring is discussed in several areas.
& Control technologies: the report dis-
cusses the efforts of the two coun-
tries in developing and deploying
pollution control technologies aimed
at reducing acidic deposition.
a Market-based incentives: the U.S.
acid rain control program is employ-
ing incentives to help reduce the cost
of emissions reductions. The two
countries are discussing the historical
and potential uses of these incentives
to achieve environmental protection at
lower costs to society.
Future cooperative efforts related to
acidic deposition include:
@ Providing up-to-date inventories of
total sulphur dioxide and nitrogen
oxides emissions.
a Measuring air quality and deposition
and refining the predictive capabili-
ties of atmospheric models.
• Recording the chemical and biologi-
cal improvements in surface waters
and responses to changing deposition.
m Determining the role of nitrogen
deposition in ecosystem processes
and the implications for control of
acidification of surface waters.
• Resolving the role of acidic deposi-
tion in damage to forests.
m Evaluating human health effects of
acidic aerosols and related pollutants.
Much of this work will be carried out
jointly or cooperatively by Canadian and
American scientists over the next several
years. Progress in these and other areas
will be reported in the next progress re-
port in 1994.
CONCLUSION
This is the first progress report under the
Canada-US. Air Quality Agreement. Since
the signing of the Agreement in March 1991,
the two countries have taken significant
steps towards implementing the Agree-
ment. They have formed a bilateral Air
Quality Committee and two subcommittees
to assist in carrying out the terms of the
Agreement. They have initiated, continued,
and expanded relationships in a variety of
areas related to North American air qual-
ity. Most importantly, there has been a
free exchange of people and information
across their border. While such exchanges
occurred prior to the signing of the Air
Quality Agreement, the number of con-
tacts and degree of cooperation and
exchange of information has increased sig-
nificantly, to the benefit of both countries.
Each Party is pleased with the cooperation
the implementation of the Agreement has
fostered.
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Preface
On March 13,1991, Canada and
the United States signed a bi-
lateral Agreement on Air
Quality. The Agreement pro-
vides the two countries with a practical
and flexible instrument to deal with shared
problems of transboundary air pollution.
This document is being issued in fulfill-
ment of the provisions in the Agreement
that call for a report on progress in its im-
plementation within a year of its entry into
force. The next progress report is due in
1994, and reports will follow every two
years thereafter.
Canada and the United States share a
long tradition of cooperation on environ-
mental matters, most notably on water
quality issues under the Boundary Waters
Treaty of 1909 and the Great Lakes Water
Quality Agreement of 1978, as amended in
1987. The Air Quality Agreement builds on
that cooperation. It recognizes that air pol-
lution, like water pollution, respects no
international boundaries. The Agreement
calls for the establishment of a bilateral air
quality committee to oversee and report on
its implementation of the Agreement. Annex
1 of the Agreement covers specific programs
and objectives and contains targets and
timetables for reducing sulphur dioxide and
nitrogen oxides, the primary acid rain pre-
cursors. This represents a fundamental step
in the resolution of a mutual environmental
problem. Finally, Annex 2 of the Agree-
ment contains provisions for cooperation
on a variety of technical activities related
to air pollution.
This report contains information on the
Air Quality Agreement itself and initial ac-
tivities of the Air Quality Committee. The
report provides background information
on the air pollution programs in both Can-
ada and the United States and discusses
progress in implementing the specific ob-
jectives in the Agreement. The subject that
is at the center of the current obligations
and scientific work is acid rain; therefore,
the focus of this first report is on our re-
spective acid rain control programs and
associated scientific and technical activi-
ties. However, the Agreement is a flexible
one, such that additional pollutants may
be added at a later date upon agreement
by the two Parties. Finally, the report ad-
dresses the future in terms of what we
hope to accomplish both individually and
cooperatively under the Agreement.
It is with a shared sense of friendship
and commitment to protecting public
health and the environment that we em-
bark on this important endeavor.
The United States-Canada
Air Quality Committee
March 1992
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SECTION I
Introduction
On March 13,1991, Prime Min-
ister Mulroney and President
Bush signed a bilateral Air
Quality Agreement in Ottawa.
The Agreement is composed of a main body
and two annexes. The body contains 16 Ar-
ticles, covering a wide variety of topics in-
cluding general and specific objectives;
assessment, notification, and mitigation;
the establishment of a bilateral Air Qual-
ity Committee; and procedures for con-
sultations, referrals, and settlement of
disputes. Annex 1 contains specific pro-
grams and objectives concerning sulphur
dioxide and nitrogen oxides, which were
designed to address acidic deposition in
both countries. Annex 2 relates to scien-
tific and technical activities and economic
research. The full text of the Agreement
can be found as Appendix B to this report.
HISTORY OF THE AGREEMENT
Canada and the United States share a
long tradition of cooperation on eco-
nomic, political, and environmental
issues. The two countries share the longest
undefended border in the world and are
each other's largest trading partner. Since
pollution knows no boundaries, they also
share transboundary transport of pollu-
tion. For many years, the two countries
have worked together on environmental
issues, most notably on water quality is-
sues under the Boundary Waters Treaty of
1909 and the Great Lakes Water Quality
Agreement of 1978, as amended in 1987.
The seeds for an agreement on air qual-
ity were sown in 1978, when Canada and
the United States established the Bilateral
Research Consultation Group (BRCG) to
facilitate information exchange, coordi-
nate research, and develop a scientific
data base on acid rain. The BRCG's first
report in 1979 showed large areas of
North America sensitive to acidic deposi-
tion (a term used to incorporate both wet
and dry deposition of acidic compounds).
In 1980, Canada and the United States
signed a Memorandum of Intent (MOD
Concerning Transboundary Air Pollution.
The MOI stated the intention of both na-
tions to develop a bilateral agreement and
vigorously enforce existing air pollution
legislation. The MOI also established work
groups to develop the scientific and techni-
cal basis for an agreement. In 1981, formal
negotiations began on a bilateral agreement,
but these negotiations broke off in 1982. In
1983, the MOI work groups published their
reports.
Throughout the 1980s, both countries
conducted research and assessment pro-
grams on the causes and effects of acidic
deposition and on the potential conse-
quences of control actions. In Canada, this
work was conducted under the auspices
of the federal/provincial Research and
Monitoring Coordinating Committee
(RMCC). In the United States, the National
Acid Precipitation Assessment Program
(NAPAP), a legislatively mandated 10-year
program created in 1980, was the focal point
for acid rain research. The RMCC published
"The 1990 Canadian Long-Range Transport
of Air Pollutants and Acid Deposition As-
sessment Report," and NAPAP published
the "Integrated Assessment Report" in
1991, as well as 27 State of Science and
Technology Reports in 1990 and 1991. The
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RMCC and NAPAP held bilateral annual
technical coordination and review meet-
ings throughout most of the 1980s,
producing a joint science report in 1987.
In 1985, Canada established a sulphur
dioxide control program in eastern Canada
that called for a reduction in 1980 emis-
sions by 1994 to a level of 2.3 million
tonnes. Canada had earlier committed to
cut emissions by at least 30 percent as part
of its commitment under the United Na-
tion's Economic Commission for Europe's
Convention on Long-Range Transbound-
ary Air Pollution (LRTAP). The United
States, meanwhile, continued to control
sulphur dioxide emissions as a result of its
ambient air quality program under the
Clean Air Act and its amendments
through 1977, and to carry out research
under NAPAP.
During the mid-1980s, dialogue on the
acid rain issue continued at the highest
levels of government. Prime Minister Mul-
roney and President Reagan, meeting in
1985, appointed Special Envoys to study
the issue of acid rain. The Special Envoys
(William Davis of Canada and Drew Lewis
of the United States) published their report
in early 1986. It recognized acid rain as a
serious transboundary problem and called
for the United States to embark on a pro-
gram of technology development and
deployment aimed at demonstrating tech-
nologies that could reduce emissions of
sulphur dioxide and nitrogen oxides from
coal-burning electric power plants. The
United States subsequently initiated the
Clean Coal Technology Program, a 5-year,
$5 billion program jointly funded by the
public and private sectors. This period
also was marked by enhanced U.S. re-
search on the causes and effects of acid
rain and by the growing emergence of a
consensus on the need to reduce precursor
emissions.
The achievement of the present Air Qual-
ity Agreement can be traced back to
February 10,1989, when President Bush met
with Prime Minister Mulroney in Ottawa.
The President committed the United States
to negotiate an air quality agreement with
Canada in conjunction with his proposal to
amend the Clean Air Act. Informal dis-
cussions were held between the two
governments during 1989 and 1990. For-
mal negotiations began in August 1990,
and concluded in December of the same
year, one month after President Bush
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signed the Clean Air Act amendments into
law in the United States. The Agreement
was signed by the two leaders in Ottawa
on March 13,1991.
Thus, the signing of the Agreement was
the culmination of over 10 years of discus-
sions on the issue of transboundary air
pollution, especially acid rain. The period
in between was marked by ongoing research
programs, technology development, intermit-
tent attempts at negotiating an agreement on
air quality, and the development of acid rain
control programs.
Article VIII of the Air Quality Agree-
ment established a bilateral Air Quality
Committee to (1) review progress made in
the implementation of the Agreement; (2)
prepare and submit to the two governments
progress reports on the implementation of
the agreement; (3) refer each progress report
to the International Joint Commission for
the solicitation of public comments and
preparation of a synthesis of views pre-
sented during comments; and (4) release
the progress report to the public after its
submission to the two governments.
The Air Quality Committee is composed
of nine representatives from each govern-
ment and has two subcommittees to assist
in carrying out its work. Subcommittee 1 is
responsible for overseeing the implementa-
tion of the specific programs and objectives
contained in Annex 1 of the Agreement. It
is also responsible for related work on
emission inventories, control technologies,
and market-based mechanisms. Subcom-
mittee 2 provides a forum for discussion
on many of the scientific and technical ac-
tivities, including atmospheric effects
research and monitoring, covered in An-
nex 2 of the Agreement. The membership
of the Air Quality Committee, as well as
the terms of reference for the committee
and two subcommittees, are included in
Appendix A to this report.
Initially, the Air Quality Committee fo-
cused on achievements in implementing the
specific programs and objectives contained
in the Agreement, assessing current coop-
erative endeavors, and discussing areas
where cooperation could be initiated or ex-
panded. The Air Quality Committee met
for the first time on November 26,1991, in
Washington, DC. That meeting focused on
relevant national and bilateral activities
and topics to be addressed in this first pro-
gress report. The two subcommittees met in
November 1991 to discuss topics such as the
implementation of respective emission re-
duction programs and atmospheric deposition
and effects research and monitoring.
The Agreement calls for each Party to
notify the other of a proposed action, activ-
ity, or project likely to cause significant
transboundary air pollution, and, as ap-
propriate, to take measures to avoid or
mitigate the potential risk posed by such
action, activity, or project. Both countries
have started to work on the criteria to be
used to implement this provision of the
Agreement.
The initial focus of
the Air Quality
Committee has been
on achievements in
implementing the
specific programs
and objectives
contained in the
Agreement, assessing
current cooperative
endeavors, and
discussing areas
where cooperation
could be initiated or
expanded.
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SECTION II
Progress: Specific
Programs and Objectives
OVERVIEW
In signing the Air Quality Agreement,
Canada and the United States com-
mitted to specific programs and ob-
jectives designed to produce cleaner
air and a healthier environment for Cana-
dians and Americans. Annex 1 to the main
Agreement sets out the commitments that
each country has made to control acid rain
precursors: sulphur dioxide (SQz) and ni-
trogen oxides (NOx). SOa is the primary
pollutant involved in the formation of acid
rain, or acidic deposition (a more exact
term that incorporates both wet and dry
deposition of acidic species). NOx also
plays an important role in the formation of
acidic deposition. It plays a predominant
role in certain regions and in certain acidic
episodes. The emission reduction pro-
grams included in Annex 1 cover both sta-
tionary sources (e.g., smelters, electric utility
plants, and industrial commercial boilers) for
SO2 and NOx reductions and mobile sources
(e.g., motor vehicles) for NOx reductions.
The Annex 1 obligations recognize the
different approaches taken by Canada and
the United States in their efforts to reduce
the effects of acidic deposition.
Canada and the United States control air
pollution by using several approaches.
Two important approaches will be de-
scribed here. The first, adopted primarily
to protect human health, sets limits for spe-
cific pollutants as concentrations in air,
e.g., parts per million of air, or micrograms
per cubic meter of air. Both countries have
air concentration limits for sulphur dioxide
and nitrogen oxides, and each has been
relatively successful in attaining these air
quality limits.
The second approach aims to reduce the
total amount of pollutant falling on a given
area, and is associated with protecting eco-
systems against the negative effects of
pollution. Loadings can be expressed as
weight of pollutant per unit of land area
per unit of time. For example, Canada has
a target loading for the eastern part of the
country of 20 kilograms of wet sulphate
per hectare of land per year. This particular
loading was developed in the early 1980s
to protect moderately sensitive surface wa-
ters against the effects of acidification. In
the United States, the dean Air Act (CAA)
as amended in 1990 limits national SOa
emissions without reference to units of
land area. The acid rain control provisions
of the CAA are designed to substantially
reduce and eventually place a cap on an-
nual emissions of SOa. These provisions
reflect, in part, a desire to reduce deposi-
tion to sensitive aquatic resources so that
acidification of lakes and streams would be
reversed or slowed down.
In concept, "total" loading involves both
wet and dry deposition. Due to the lack of
information on the dry deposition compo-
nent, the early development of the total
loading concept focused on wet deposition
alone. This approach is probably more ap-
propriate for Canada and for regions of the
United States where dry deposition rates are
low, and less appropriate for areas where
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the relative contribution of dry deposition
to overall deposition is larger and/or more
regionally variable.
Both countries have experienced acidifi-
cation of surface waters in geographically
diverse areas, which led to policies de-
signed to reduce the deposition of sulphur
compounds on watersheds. A concern also is
shared for the effect of acidic deposition on
forests and forest soils, and on materials,
and for the potential health threat posed
by elevated levels of acidic aerosols in the
atmosphere. In the United States, there
also has been a great concern about the ad-
verse effect of air concentrations of
sulphate particles on visibility in the east-
ern part of the United States and in
national parks and wilderness areas of the
west (e.g., Glacier National Park, the
Grand Canyon).
In the sections that follow, the obligations
of the two governments relating to specific
programs and objectives are summarized,
and progress toward the fulfillment of
those obligations is noted. Areas covered
include emission reduction goals, affected
sources, timing of reductions, geographic
domain, methods used to achieve reduc-
tions, and emissions monitoring. In
addition, a discussion of "prevention of
significant deterioration" and visibility
protection in the context of the Air Quality
Agreement is included.
SULPHUR DIOXIDE
Overview of Obligation/
Emission Reduction Goals
Both countries have undertaken obliga-
tions to reduce emissions of sulphur
dioxide from stationary sources and to im-
plement caps on those emissions. In this
report, short tons ("tons") and metric tons
("tonnes") are used. One ton is equal to 0.9
tonnes. Conversely, one tonne is equal to
1.1 tons. In accordance with Annex 1, Can-
ada is obligated to reduce SO2 emissions in
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the seven easternmost provinces to 2.3 mil-
lion tonnes per year by 1994, and to
maintain an annual cap of 2.3 million
tonnes on those emissions through Decem-
ber 31, 1999. Furthermore, Canada is
committed to achieving a permanent na-
tional cap on SO2 emissions of 3.2 million
tonnes per year by the year 2000. The
United States is committed to reducing an-
nual SOa emissions by approximately 10
million tons below 1980 levels by the year
2000, with the exception of sources repow-
ering with qualifying clean coal
technologies and those receiving bonus al-
lowances in accordance with provisions
contained in the CAA. The United States'
commitment represents a reduction of ap-
proximately 40 percent in SOi emissions
compared to 1980, the base year used in
both Canada and the United States for
measuring progress in their respective
acid rain control programs. In addition,
the United States is committed to achiev-
ing a permanent national cap of 8.95
million tons of SO2 per year for electric
utilities by 2010. Finally, the United States
is committed to ensuring that industrial
emissions of SOz do not exceed 5.6 million
tons, in accordance with provisions con-
tained in the CAA.
Trends and targets for SC>2 emissions in
Canada and the United States are in Figure
1, which illustrates the long-term down-
ward trend in emissions in both countries.
Implementation Overview
Canada
In 1985, the federal government and the
governments of the seven easternmost
provinces agreed to establish a program to
reduce emissions of SOa.
Figure 1
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The Eastern Canada program requires
that total annual SOa emissions from the
provinces east of Saskatchewan be reduced
to 2.3 million tonnes by the end of 1994, a de-
crease of about 40 percent from the 1980
level of 3.8 million tonnes. Each province
agreed to a specific overall reduction target
and timetable. In essence, a "bubble" has been
placed over each province, and the province
left to decide how to achieve the reduction
needed to stay within the 'bubble" or emis-
sion cap. The 1980 emission levels and the
1994 targets are contained in Figure 2.
In general, control efforts have been di-
rected at major SOa sources, such as non-fer-
rous metal smelters and fossil fuel burning
power plants, where the largest and most
cost-effective reductions can be achieved.
These sources emitted about 62 and 20 per-
cent, respectively, of Canada's SOa emis-
sions in 1985. As a result, six large copper,
nickel, and zinc smelters; one iron ore sin-
tering plant; and three provincial electrical
utilities are responsible for implementing
the major portion of the control program.
In the case of smelters, provinces have
established regulated emission levels for
each individual smelter. However, electric
utilities in most provinces have been allo-
cated a specified share of the provincial
cap for 1994, and have been allowed to
trade freely among their various power
plants and generating units within the
province to meet their allocation. The form
of control imposed allows these source sec-
tors to choose among the range of poten-
tial control options, including such
methods as process changes in the case of
smelters, fuel switching or energy conser-
vation programs to reduce electricity de-
mand in the case of power plants, or
back-end control technologies in either
case. Some of the provincial programs also
contain controls for other sectors, such as
limits on the sulphur content of heavy fuel
oil in Ontario and Quebec, and regulated
emission limits for pulp mills and refiner-
ies in Quebec.
Between 1987 and 1994, the major emit-
ters will invest about $1.7 billion in capital
projects to reduce their SOa emissions. The
average annual investment over the period
is $248 million per year, but, during the fi-
nal four years, the investment in capital
projects will be approximately $352 mil-
lion per year.
Investments in capital projects will con-
tinue beyond the end of 1993. For example,
Ontario Hydro will continue to invest
about $206 million a year in abatement
projects from 1994 to the end of 1998 in or-
der to keep emissions below the limit
while allowing for growth in electrical
generation. Nova Scotia Power will invest
another $170 million between 1994 and
2010 for the same reason.
Since the signing of the Air Quality
Agreement in 1991, considerable progress
has been made towards meeting the 2.3
million tonne target for 1994. During the
past year, remedial measures to reduce
emissions from existing SOa sources in
eastern Canada included:
m Awarding of contracts for wet lime-
stone scrubbers for two of the four
500 MWe generating units at the
Lambton power plant in Ontario.
B Release of a revised supply/demand
plan by Ontario Hydro, which fea-
tures increased reliance on existing
facilities and, linked to their life ex-
tension, the possible retrofit of up to
-------
10 units with flue gas desulphuriza-
tion (FGD, or "scrubbers").
Commencement of operation of a new
ore processing mill at the Inco smelter
at Sudbury, Ontario, to remove con-
centrated sulphur (phyrrhotite) from
the ore before it enters the smelter,
and the completion of the first of two
flash furnaces that will allow much
higher recovery of SO2 in the
smelter's acid plant.
Completion of major changes in 1990
to the smelting process at the No-
randa, Quebec, smelter that substan-
tially increase the efficiency of
sulphur capture at the new acid plant
installed in 1989.
Enactment of a sulphur in fuel oil
limit of 1.5 percent for the power
plant at Tracy, Quebec, and 2.0 per-
cent for existing industrial boilers in
Quebec.
Acceleration of demand management
and efficiency programs by Canadian
electric utilities to forestall the need
for new generating capacity and to
reduce fossil fuel consumption.
Beginning of a $187 million project to
modernize Hudson Bay Mining and
Smelting's Flin Flon, Manitoba,
smelter. As part of the project, there
will be a replacement of the current
zinc plant by a zinc pressure leach
plant. This will reduce SOa emissions
by 25 percent, from 293,000 to 220,000
tonnes, allowing Manitoba to meet its
new emission limit by 1994.
SUBMISSION REDUCTION GOALS
iCanada
^s • "SQz emissions reduction in 7 easternmost provinces
-ZT to 2.3 million tonnes by 1994
JTH Maintenance of 2.3 million tonne annual cap through
—December 1999
I T'ermanent national annual cap on SOa emissions of
" 3.2 million tonnes by the year 2000
States
SQz emissions reduction by 10 million tons from 1980
•**"*"••• levels by the year 2000
Permanent national cap of 8.95 million tons for
^electric utilities by the year 2010
Cap of 5.6 million tons for industrial source emissions
• Decision to convert the 315 MWe
Dalhousie power plant in New
Brunswick to an orimulsion fuel and
install a scrubber.
At new sources in Eastern Canada,
measures are being taken to minimize ad-
ditional SOz emissions and to ensure that
provincial caps are not exceeded. During
the past year:
a Tenders were awarded for an SQz
scrubber at the 450 MWe coal-fired
Belledune power plant under construc-
tion in northern New Brunswick.
a A 1.5 percent sulphur content limit
for heavy fuel oil was enacted in
Quebec for all new industrial boilers.
• Construction proceeded on the 165
MWe fluidized bed power plant at
15
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TABLE 1. Annual SO
Newfoundland
Power Generation
Total
Prince Edward Island
Power Generation
Total
Nova Scotia
Power Generation
Total
New Brunswick
Primary Metals
Power Generation
Total
Quebec
Primary Metals
Total
Ontario
Primary Metals3
Power Generation
Total
Manitoba
Primary Metals3
Total
Eastern Canada
Primary Metals3
Power Generation
Other
Total
2 Emissions and Targets for Eastern Canada (kilotonnes)
EMISSIONS
I9601
18
56
2
5
125
193
13
122
220
641
1,098
1,031
398
1,764
463
484
2,148
665
1,007
3,820
19851
22
43
3
130
170
17
94
138
483
693
899
337
1,457
459
469
1,858
583
532
2,973
19901
23
47
2
3
143
178
8
141
187
189
396
730
195
1,250
489
505
1,416
504
646
2,566
TARGETS
1994
45
5
204
185
6004
885
550
2,4742
Notes:
1 Numbers for 1980 and 1985 are taken from Environment Canada Report RPS 5/AP/3, March 1990. Estimates for 1990 are prelimi-
nary numbers based on submissions from provinces.
2 The 1994 Eastern Canada limit is 2,300 kilotonnes. The current total of agreed-to objectives is 2,474 kilotonnes; the remaining 174
kilotonnes is expected to be allocated sometime in 1992 through amendment of the current federal/provincial agreements.
3 Primary metal includes non-ferrous smelters and iron ore benefidation but excludes aluminum production.
4 The target for Quebec of 600 kilotonnes is for the year 1990; the province opted to complete its reduction program in 1990 rather
than in 1994.
16
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Point Aconi, Nova Scotia, which will
have 90 percent SOa removal capac-
ity and NOx emissions at least 30
percent below current new source
standards.
The 1990 data on Canadian SOa emis-
sions indicate that emissions in Eastern
Canada are now within about 16 percent
of the program target of 2.3 million tonnes
by 1994.
A new program that will aim at allow-
ing Canada to maintain a national cap of
3.2 million tonnes by December 31,1999, is
being developed. Reductions currently oc-
curring under the Eastern Canada pro-
gram also are contributing to a decline in
SO2 emissions nationally towards the 3.2
million tonne level. Emissions nationally
in Canada were 4.6 million tonnes in 1980
and by 1990 had declined to 3.5 million
tonnes, or nearly 80 percent of the reduc-
tion needed to reach the 3.2 million tonne
target. More information on the national
program should be available for the next
progress report.
United States
The U.S. SOa emission reductions will
be implemented primarily through the use
of an innovative system of SOa emission
allowances. Each allowance permits its
holder to emit one ton of SOa during or af-
ter a given year. Allowances will be allo-
cated to affected utility units based on
their historic fuel use and emission rates
specified in the CAA amendments. Once
allocated, allowances are fully marketable.
They can be sold to other parties or
banked for future use. The primary re-
quirement of the acid rain program is that
sources hold a sufficient number of allow-
ances at the end of the year to cover their
annual emissions. At the end of the year,
emissions data will be compared to emis-
sion allowance holdings to determine
compliance. If a unit fails to hold a suffi-
cient number of allowances to cover its
emissions, it must pay an excess emissions
fee of $2,000/ton for every ton in excess of
the allowances held. In addition, the non-
complying unit would have to forfeit al-
lowances from the next year's allocation to
offset the excess emissions.
Affected Sources, Timing,
and Cost of Reductions
The U.S. SOa emission reductions will
be implemented in two phases, which will
entail a tightening of the restrictions
placed on fossil fuel-fired electric generat-
ing plants. The first phase commences
January 1, 1995, and the second phase
commences January 1, 2000. In the first
phase, 261 units at 110 electric utility
plants in 21 eastern states will be affected.
These sources will be allocated the number
of allowances specified in the CAA. The al-
locations were calculated on the basis of
each unit emitting at 2.5 pounds SOa per
million British Thermal Units (BTUs) heat
input. At the end of 1995 and each year
thereafter, these Phase I units must hold a
sufficient number of allowances to cover
their annual emissions.
In Phase II, approximately 2,500 electric
generating units serving generators with
capacities of 25 megawatts or greater (in-
cluding those covered under Phase I) will
be allocated allowances based on a series
of formulas contained in the legislation.
This allocation will result in a substantial
reduction in allowable utility emissions of
SOa. In 2010,when the program is fully imple-
mented, the annual allocation of allowances
17
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will result in a national emission cap on
utility units of 8.95 million tons. Under the
acid rain program, new utility units, includ-
ing those smaller than 25 megawatts, will
not be allocated emission allowances but will
be required to obtain allowances from others
to cover their emissions.
The market-based allowance system has
been estimated to reduce costs of compliance
with acid rain control provisions by approxi-
mately 20 percent compared to traditional
"command and control" approaches. The
costs of the acid rain control program in the
United States have been estimated at ap-
proximately $1 billion a year in Phase I and
approximately $4 billion a year in Phase II.
Therefore, the potential cost savings from
using a market-based system are signifi-
cant. The market-based approach was
given added support in 1991 when the Chi-
cago Board of Trade announced its
intention to establish a futures market in
emission allowances.
Geographic Domain of
Control/Deposition Patterns
The United States acid rain control pro-
gram applies to the 48 contiguous states
and the District of Columbia (Hawaii and
Alaska are not covered). All sources that
meet defined criteria will be subject to the
requirements articulated in Title IV of the
CAA. As noted above, the sources affected
in Phase I that will have to undergo emis-
sion reductions starting in 1995 are all
located in the eastern part of the country
where most older, higher emitting plants
are located. The states with the largest
number of affected units and required
emission reductions are Ohio, Indiana, Il-
linois, Pennsylvania, and West Virginia.
Early indications suggest that some sources
in these states will choose to control beyond
the requirements of the legislation, and
will sell their excess allowances to units in
their own or other states where the cost ef-
fectiveness of emission reductions is lower.
Analyses conducted under the auspices
of NAPAP suggest that emissions trading,
which is designed to increase economic ef-
ficiency in achieving emission reductions,
would not lead to broad regional differ-
ences in deposition patterns compared to
an approach that would not allow trading.
One of the practical reasons for this is that
emissions of sulphur dioxide in the United
States are heavily concentrated in the mid-
western part of the country, and switching
emission reductions among sources would
not result in dramatic changes over thou-
sands of square miles in the United States
and Canada. Once the emission reduction
program in the United States is imple-
mented and actual trading has taken place,
the United States will conduct analyses of
the economic and environmental conse-
quences of trading.
Compliance Methods
Under the U.S. acid rain control pro-
gram, a source can decrease its emissions
to meet the number of allowances it holds,
increase the number of allowances it holds
up to the level of its legal level of emis-
sions, or combine these two options. If a
source chooses to reduce its emissions to
meet the number of allowances it holds, it
has several options available to it. These in-
clude employing energy conservation
measures, increasing reliance on renewable
energy, reducing utilization, employing pol-
lution control technologies, or switching to
lower sulphur fuel. If a source chooses to
increase its allowance holdings to the level
of its emissions, it can transfer them from
18
-------
another unit in its system that has an ex-
cess; buy allowances from a broker or from
another utility that may have exceeded its
control requirements (thus having allow-
ances available to sell); buy allowances
from an industrial plant or unaffected util-
ity that elects to opt into the allowance
system; or, buy allowances through a legisla-
tively required EPA-sponsored allowance
auction and sale program. The method(s)
that any individual source selects to com-
ply with the requirements of the law will
be determined by the source. While the
government will eventually evaluate the
impact of compliance decisions, it will not
dictate which compliance measures sources
must select.
Since Phase I of the acid rain control
program does not require emission reduc-
tions until 1995, it is too early to report on
actual compliance decisions. However, it is
apparent that a significant number of utili-
ties are making plans to install scrubbers to
comply with Phase I reduction require-
ments. A good deal of specific information
on Phase I reduction decisions is likely to
be available by the time the next progress
report is published in 1994.
Progress in Implementing Sulphur
Dioxide Obligations
The past year has been an active one in
terms of implementing the acid rain con-
trol provisions of the CAA and the
requirements of Annex 1 of the Air Quality
Agreement. Under the U.S. system, Con-
gress sets out the requirements of the
program, and the executive branch of gov-
ernment is responsible for developing and
promulgating the regulations that define
how the law will be implemented. The ex-
ecutive branch has the responsibility to
promulgate regulations implementing the
acid rain control program. In December
1991, EPA promulgated final rules on the
auction and direct sale of allowances and
proposed rules in four areas of critical im-
portance to the acid rain program:
sulphur dioxide allowances, acid rain per-
mits, continuous emission monitoring, and
excess emissions.
Future regulations include the allow-
ance allocation rule, which sets forth the
initial allocation of allowances that each
utility unit will receive and the "opt-in"
rule, under which industrial sources will
be given an opportunity to opt-in to the al-
lowance system. These rules are all subject
to public review and comment periods
within the United States, and most are ex-
pected to be finalized by the end of 1992.
By the next Air Quality Agreement pro-
gress report, there will be significant
movement toward Phase I compliance. For
example, by February 1993, all Phase I
sources will be required to submit permit
applications and compliance plans, mak-
ing it much clearer how Phase I units
intend to comply with their emission lim-
its. Additionally, all Phase I units will have
to install continuous emission monitors by
the end of 1993.
NITROGEN OXIDES
Canada
Under Annex 1 of the Air Quality
Agreement, Canada committed to reduce
its nitrogen oxides (NOx) emissions from
stationary sources by 100,000 tonnes from
a forecast emission level of 970,000 tonnes
in the year 2000. In addition, Canada is
committed to implementation of more
stringent NOx emission standards for
19
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light, medium, and heavy duty vehicles
through the period 1996 to 1998.
Canadian NOx emissions were 1.9 mil-
lion tonnes in 1985, with 63 percent origi-
nating from mobile sources, mainly light
and heavy duty vehicles and off-road die-
sel equipment. Major stationary sources
include power plants, boilers and heaters,
pipeline compressors, and gas turbines. If
no further controls other than those al-
ready in place are implemented, it is esti-
mated that by 2000, NOx emissions from
stationary sources will rise to 970,000
tonnes from a level of 707,000 tonnes in
1985, and those from mobile sources will
drop to 960,000 tonnes from a level of 1.18
million tonnes in 1985.
Emission reductions will be achieved
through the implementation of the Man-
agement Plan for Nitrogen Oxides (NOx)
and Volatile Organic Compounds (VOCs).
The federal-provincial plan was developed
by the Canadian Council of Ministers of
the Environment and adopted in principle
in November 1990.
The NOx/VOC Management Plan is di-
rected specifically at reducing the expo-
sure of Canadians and the Canadian
environment to excessive concentrations of
ground-level ozone. The plan also is in-
tended to ensure that Canada meets its in-
ternational obligations for NOx controls.
These are found in the United Nations
Economic Commission for Europe NOx
Protocol of 1988 (under the Convention on
LRTAP) and the Canada-United States Air
Quality Agreement of 1991. It must be
noted that because ground-level ozone is
regional in nature, national NOx emission
reduction targets were not viewed as ap-
propriate control criteria. Consequently,
there are no national emission reduction
targets set out in the NOx/VOC Manage-
ment Plan.
Measures identified in the NOx/VOC
Management Plan for mobile sources in-
clude a more stringent standard of 0.4
grams per mile (gpm) of NOx for cars and
trucks by 1994, a 5 g/BHP-hr standard for
heavy duty trucks (already in place on a
voluntary basis) by 1994 and tighter stand-
ards of 4 g/BHP-hr by 1998, standards for
off-road diesel equipment, and a cap on
NOx emissions from rail transport. Re-
garding the more stringent NOx standard
for passenger cars, Transport Canada an-
nounced on February 20, 1992, a formal
agreement with major automobile manu-
facturers on voluntary compliance with
standards equivalent to those in the
United States for 1994 and 1995, pending
introduction of a regulation under the Mo-
tor Vehicle Safety Act for the 1996 model
year.
Control measures proposed for new sta-
tionary sources include more stringent
NOx emission limits for power plants, tur-
20
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bines, industrial-commercial boilers and
heaters, and large stationary reciprocating
engines. In addition, provinces are devel-
oping remedial NOx reduction programs
for major existing stationary NOx sources
in ozone non-attainment areas. These
sources include power plants, commercial
iron and steel mills, and refineries.
The NOx reduction program is now be-
ing formalized in federal-provincial agree-
ments that will allocate responsibility for
achieving emission reductions and for
monitoring and reporting of results.
It is expected that reduction of NOx
emissions nationally from all sources will
amount to about 175,000 tonnes by the
year 2000. This represents a 7.2 percent re-
duction from the 1985 emission level. Re-
ductions in key source areas that have the
greatest effect on acidification will be
greater than the national average.
A second phase of the NOx/VOC Man-
agement Plan will be developed by 1995.
More NOx emission reductions are likely
to be required in this second phase and
will form the basis for the program to meet
the commitment in the Air Quality Agree-
ment for further annual national emission
reduction requirements from stationary
sources to be achieved by 2000 and/or
2005.
United States
Under Annex 1 of the Air Quality
Agreement, the United States is obligated
to implement a NOx control program with
a view to a reduction of total annual emis-
sions of NOx of approximately 2 million
tons from 1980 levels of 21 million tons.
The emission reductions will come from
both stationary sources (electric utility
plants) and mobile sources (motor vehi-
cles), and will be achieved by setting new
emission limits for these sources. Unlike
the emission limits for SO2, which are de-
fined in terms of total tons, the emission
limits for NOx are set in a more traditional
manner. For electric utility boilers, the lim-
its are set as pounds of NOx per million
BTUs, while for automobiles, they are set
as grams of NOx per mile; unlike the SOz
control program, there are no tonnage lim-
its on the amount of NOx that can be emit-
ted. In the absence of new controls, the
NOx emissions from electric utility plants
were projected to be approximately 2 mil-
lion tons higher in the year 2000 than they
were in 1980. Mobile sources are projected
to experience a real decline in emissions by
the year 2000 compared to 1980, such that
the actual emission reductions from all
sources are likely to be well over 2 million
tons.
The NOx control provisions in the
United States are specified in both Title II
(mobile sources) and Title IV (acid deposi-
tion control) of the CAA; parallel require-
ments are spelled out in Annex 1 of the Air
Quality Agreement. Substantial NOx con-
trol also is expected under Title I of the
CAA, but the magnitude and location of
these reductions is subject to future state
and federal discussions.
Under the mobile source provisions, the
gpm for NOx limits will be phased-in
starting with the 1994 model year for light
duty vehicles and some light duty trucks,
and will be fully implemented by the 1996
model year for light duty vehicles and the
1997 model year for light duty trucks. The
NOx limits for heavy duty trucks will be
phased-in beginning in 1991 and will be
fully implemented by 1998. The standard
will be 0.4 gpm for light duty vehicles
22
-------
(which includes passenger cars). The
standard for cars represents about a 60 per-
cent decrease from the current standard.
Regulations implementing this provi-
sion of the CAA were promulgated in June
1991. In addition, the useful life of pollu-
tion control equipment has been extended
from 50,000 miles to 100,000 miles. Con-
gress, in the law, also required EPA to
make a determination by the end of 1999
whether or not there is a need to further re-
duce NOx emissions from vehicles (i.e., to
go down to 0.2 gpm from 0.4 gpm). The
NOx control provisions will affect all auto-
mobiles sold in the United States, with
some areas (e.g., California) adopting even
stricter standards.
Under the U.S. acid rain control pro-
gram, the new standards must be set for
different classes of boilers used in the pro-
duction of electricity. These requirements
also will be implemented in two phases.
EPA will establish Phase I emission limita-
tions to be met by two types of boilers by
1995. Subsequent regulations for affected
units not subject to the Phase I NOx limits
will be met in Phase II. The rules to imple-
ment the Phase I NOx requirements cur-
rently are being developed.
COMPLIANCE MONITORING
In Annex 1 of the Air Quality Agree-
ment, Canada and the United States
undertook certain obligations regarding
the monitoring of emissions from electric
utility units and other major stationary
sources. For all new electric utility units
and existing units greater than 25 MWe,
Canada is required to estimate emissions
of SOa and NOx using a method compara-
ble in effectiveness to continuous emission
monitors and to investigate the feasibility
of using continuous emission monitoring
systems. Continuous emission monitoring
(CEM) is the measurement on a continu-
ous basis of pollutants emitted into the
atmosphere in exhaust gases from combus-
tion processes or as by-products of
industrial processes. This requirement be-
comes effective January 1, 1995. For the
United States, the requirement is that, by
January 1, 1995, each new electric utility
unit and each electric utility unit greater
than 25 MWe that existed at the time of the
signing of the CAA amendments (Novem-
ber 15,1990) emitting SO2 or NOx install and
operate continuous emission monitoring
systems or alternative systems approved by
the Administrator of EPA, to the extent re-
quired by section 412 of the CAA. The
Parties agreed to consult, as appropriate,
concerning the implementation of these re-
quirements. For other major stationary
sources, such as smelters and industrial
boilers, Canada and the United States have
agreed to work toward utilizing compara-
bly effective methods of emission
estimation for SO2 and NOx.
Canada
SO2 and NOx emissions are being con-
tinuously monitored at several Canadian
power plants, although the majority of
plants are not yet being monitored. The
1981 Federal Thermal Power Generation
Emissions—National Guidelines for New
Stationary Sources recommends that a con-
tinuous monitoring system for SOa and
NOx be installed on each new source.
The current revision of this national
standard, being prepared as part of the
NOx/VOC Management Plan, will include
a requirement for continuous NOx emis-
sion monitoring at new power plants.
22
-------
Some provinces (e.g., Saskatchewan) have
programs to install continuous emission
monitors on their existing power plants.
Canada will be further evaluating actions
required to fulfill its commitments under the
Agreement and will report in more detail on
its SOa and NOx compliance monitoring
programs in the second progress report. The
United States is sharing information with
Canada on the implementation of the CEM
requirements of the CAA in order to assist
Canada in its evaluation.
United States
In December 1991, EPA proposed a
CEM rule as part of its overall implemen-
tation of the acid rain control provisions of
the CAA as amended in 1990. Equipment
required by the proposed rule must be in-
stalled, certified, and operational by No-
vember 15,1993, for Phase I affected units,
and by January 1,1995, for Phase II units.
CEMs are an important component of the
SO2 market-based allowance system that
will be utilized, helping to ensure that
complete and accurate emissions data are
available.
Under the proposed rule, the owner or
operator of a unit regulated under Phase I
or Phase II (or a unit that opts-in to the
program) and any new unit must install a
CEM system on the unit unless otherwise
specified in the regulation. A CEM system
generally might include:
m a sulphur dioxide pollutant concen-
tration monitor;
BJ a nitrogen oxides pollutant concen-
tration monitor;
ig a volumetric flow monitor;
a an opacity monitor;
n a diluent gas monitor; and
n a data acquisition and handling sys-
tem (computer-based) for recording
and performing calculations with the
data.
Regarding the methods used to estimate
emissions from major stationary sources
other than electric utility units, Canada
and the United States work together on
these issues as part of their joint work on
emission inventories. In general, it can be
said that the two countries' approaches to
estimating emissions from these sources
are both compatible and comparable.
Work continues on refining these methods.
These types of emissions are important,
because, for example, non-utility source
emissions of sulphur dioxide represent ap-
proximately 70 percent of total sulphur di-
oxide emissions in Canada, and 25 percent
of total sulphur dioxide emissions in the
United States.
PREVENTION OF SIGNIFICANT
DETERIORATION AND
VISIBILITY PROTECTION
Annex 1 of the Air Quality Agreement
contains provisions on prevention of sig-
nificant deterioration (PSD) and visibility
protection with respect to sources that
could cause significant transboundary air
pollution. Canada is obligated to develop
programs by January 1, 1995, while the
United States is obligated to continue its
PSD and visibility protection programs
relative to transboundary effects to the ex-
tent required by the CAA.
Subcommittee 1 of the bilateral Air
Quality Committee is responsible for pro-
viding a forum for discussion on issues
23
-------
relative to the implementation of the
Agreement's provisions on PSD and visi-
bility protection. The United States is
sharing information with Canada on the de-
velopment and implementation of these
programs in the United States as a means of
helping Canada in the development of its
own PSD and visibility protection programs.
In this section, a brief description of the
PSD and visibility programs in the United
States is presented. For analyses of histori-
cal and present visibility conditions in the
United States and expected changes result-
ing from changes in sulphate concentrations,
please refer to the NAPAP State of Science
Report No. 24 and the 1990 Integrated
Assessment.
Prevention of Significant
Deterioration
The U.S. PSD program was designed to
keep air in areas with clean air clean. The
basic goals of the PSD program are (1) to
ensure that economic growth will occur in
harmony with the preservation of existing
clean air resources; (2) to protect the public
health and welfare from any adverse effect
that might occur even at air pollution lev-
els lower than the National Ambient Air
Quality Standards (NAAQS); and (3) to
preserve, protect, and enhance the air qual-
ity in areas of special natural recreational,
scenic, or historic value, such as national
parks and wilderness areas (called "Class I
areas"). The primary provisions of the PSD
regulations require that major new station-
ary sources and major modifications to
existing sources be carefully reviewed
prior to construction to ensure compliance
with the NAAQS, the applicable PSD air
quality increments, and the requirement to
apply the best available control technology
(BACT) to minimize the projects' emis-
sions of air pollutants.
No new major source or major modifi-
cation subject to PSD review may be
constructed without a permit. To obtain a
PSD permit an applicant must (1) apply
BACT; (2) conduct an ambient air quality
analysis; (3) analyze impacts to soils, vege-
tation, and visibility; (4) not adversely
impact a Class I area; and (5) undergo an
adequate public review process.
Briefly, a "major stationary source" is
any source belonging to a list of 28 source
categories which emits or has the potential
to emit 100 tons per year or more of any
pollutant subject to regulation under the
Act (both sulphur dioxide and nitrogen ox-
ides are covered), or any other source
which emits or has the potential to emit
such pollutants in amounts equal to or
greater than 250 tons per year.
A "major modification" is generally a
physical change or a change in the method
of operation of a major stationary source
which would result in a "significant" net
increase in the emissions of any regulated
pollutant. The quantity of net emission in-
crease that qualifies as "significant" varies
by pollutant but generally is about 40 tons
per year.
Visibility Protection Program
Sulphur dioxide is the primary pollut-
ant associated with visibility degradation.
Sulphate particles are responsible for over
50 percent of visibility degradation in the
eastern part of the United States, and are
important in the western part of the coun-
try, which has a large number of national
parks and wilderness areas.
24
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In 1977, Congress amended the CAA by
adding section 169A, which charged EPA
with developing regulations to protect
visibility in certain national parks and wil-
derness areas. "Mandatory Class I Federal
areas" are certain national parks, wilder-
ness areas, and international parks.
Congress, at that time, set forth a national
goal of preventing any future and remedy-
ing any existing visibility impairment in
those areas caused by manmade pollution.
It is known mat fine particulate matter,
either emitted directly by manmade and
natural sources or formed in the atmos-
phere by reactions of gaseous precursors,
is the major cause of visibility impairment.
In 1979, EPA identified 156 mandatory
Class I areas where visibility was deter-
mined to be an important air quality-related
value. In December 1980, EPA promul-
gated visibility regulations to assure
progress toward meeting the national
goal. The regulations promulgated by EPA
address visibility impairment that can be
traced to a single source or a small group
of sources.
A visibility monitoring program was es-
tablished which tracks atmospheric light
extinction levels along with fine particle
pollution levels in many parks and wilder-
ness areas. EPA works cooperatively with
the other federal agencies that administer
the parks and wilderness areas (e.g., the
National Park Service and the Forest Serv-
ice) in establishing monitoring programs
and reviewing visibility data on impair-
ment. EPA also is planning to track
improvements in visual air quality ex-
pected from the implementation of the
program to reduce acid deposition in the
East. This effort will cover areas outside of
the national park and wilderness system.
EPA also is conducting research on re-
gional transport of pollution which affects
visual air quality. The large regional reduc-
tions in SOa emissions were achieved
under the acid rain control provisions of
the CAA that were enacted, in part, to re-
duce sulphate-based visibility impairment.
EPA will continue to develop techniques
to analyze regional transport of visibility-
impairing pollutants. Under the CAA, the
Grand Canyon Commission, consisting of
seven western states, was formed to study
regional transport in the desert southwest
and make program recommendations to
EPA regarding visibility protection.
25
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-------
SECTION III
Progress: Scientific and
Technical Activities and
Economic Research
OVERVIEW
In Annex 2 of the Air Quality Agree-
ment, Canada and the United States
have agreed to coordinate certain ac-
tivities and to cooperate on others.
Specifically, they have agreed to coordi-
nate monitoring networks and emission in-
ventory activities and to cooperate on
effects monitoring, effects research, atmos-
pheric modeling, control technologies, and
analyses of market-based mechanisms to
achieve environmental goals. The two Par-
ties have agreed that, initially, the primary
focus of these activities will be on acidic
deposition and its precursors.
Both countries have had active pro-
grams in most of these technical and
scientific areas over the past decade. Given
the importance of acid rain as both a do-
mestic and bilateral issue, both countries
conducted extensive research programs in
the 1980s on the causes and the effects of
acidic deposition. As noted earlier, in Can-
ada this program was coordinated by the
federal/provincial Research and Monitor-
ing Coordinating Committee (RMCC). The
RMCC was composed of Environment
Canada and the 10 provincial ministries of
the Environment. In 1990, the RMCC pub-
lished its summary analyses in an
eight-volume report titled, "The 1990 Cana-
dian Long-Range Transport of Air Pollutants
and Acid Deposition Assessment Report."
The report includes an executive summary
and volumes on emissions and controls, at-
mospheric science, aquatic effects, terrestrial
effects, human health effects, socio-economic
studies, and quality assurance.
In the United States, the focal point for
acid rain research was NAPAP, a federal
interagency effort that included EPA; the
National Oceanic and Atmospheric Admini-
stration; the Council on Environmental
Quality; and the Departments of Energy,
Agriculture, and Interior. NAPAP spent 10
years and over $500 million studying the
causes and the effects of acid rain and exam-
ining the potential effects of various control
strategies. In 1990, NAPAP produced 27
State of Science and Technology Reports
and an Integrated Assessment. The effects
categories examined included aquatic, ter-
restrial (forests and crops), materials,
visibility, and human health; other areas
included emissions monitoring and projec-
tions; atmospheric processes, modeling
and deposition; control technologies; and
economic and valuation analyses. NAPAP
was reauthorized under the CAA amend-
ments of 1990 to coordinate monitoring
activities, identify research gaps, and re-
port on the status and effectiveness of the
acid deposition control program. NAPAP
must periodically report its findings to the
President and Congress.
Canada and the United States both con-
duct a wide variety of scientific and
technical activities related to acidic deposi-
27
-------
During the past year,
the two countries
have met to discuss a
variety of topics
related to emission
inventories,
including the
production of a 1990
inventory,
integration of
Canadian and U.S.
emission data and
projections of future
emissions.
tion. For example, emission inventories are
developed, atmospheric models are used to
plot deposition and air concentration maps,
deposition and air concentration monitoring
sites are maintained, the mechanisms of pol-
lutants acting on the environment are
studied in the laboratory and in the field,
and there is monitoring of the effects on the
environment (e.g., surface water sampling).
This report contains some key information
and highlights in all of these areas, in addi-
tion to the development of pollution
reduction technologies and the use of mar-
ket-based incentives. More detailed,
in-depth information on most of these top-
ics can be found in the publications of the
RMCCandNAPAP.
Throughout this report, the terms "acid
rain" and "acidic deposition" are both
used. "Acid rain" is a simple term that has
been used for many years and gained
widespread public recognition. The sci-
ence of acidification processes is more
complex than the term "acid rain" implies.
The problem of acidification goes beyond
the acidity of rain; it also includes the
acidifying effects of chemicals that are in
the air or involved in deposition to the
earth's surface when it is not raining.
"Acidic deposition" incorporates both wet
and dry conditions. While many chemicals
are involved in acidic deposition, it is the
sulphur and nitrogen compounds of the
overall deposition problem that are central
to most of the scientific questions that arise,
and are therefore the focus of this report.
EMISSION INVENTORIES
In Annex 2 of the Air Quality Agree-
ment, Canada and the United States
agreed to coordinate emission inventory
activities for the purpose of ". . .determin-
ing and reporting air emissions levels, his-
torical trends, and projections with respect
to the achievement of the general and spe-
cific objectives set forth in [the]
Agreement. . .". In Annex 2, the two Par-
ties also agreed to the use of measurement
and estimation procedures of comparable
effectiveness and to the use of compatible
data management procedures, formats,
and methods.
Emission inventories are estimates of
emissions of various pollutants that are
used for air quality management purposes.
National emission inventories are collected
for a number of pollutants, including sul-
phur dioxide and nitrogen oxides. Emissions
of pollutants are usually broken down by
amount from different source categories,
including stationary sources (e.g., electric
power plants, smelters, factories), mobile
sources (e.g., cars and trucks), and natural
sources (e.g., volcanoes, vegetation). Emis-
sion inventories are calculated by a variety
of methods, including mass balance, data
from monitors, and the application of
emission factors to various sources. The
development of emission inventories is an
evolutionary process, with constant devel-
opment of new methods and enhancement
of older ones. For example, the U.S. pro-
gram to install continuous emission
monitors on all the units affected by the
acid rain control provisions of the CAA
will provide a high degree of precision to a
substantial portion of the United States'
sulphur dioxide and nitrogen oxides emis-
sions inventories.
Canada and the United States have
worked together to produce emission in-
ventories before and are continuing to
work together. The most significant coop-
eration to date occurred during the
28
-------
compilation of the 1985 inventory devel-
oped under the auspices of NAPAP. The
NAPAP Inventory contained information on
both Canadian and US. emissions for a vari-
ety of pollutants, including sulphur dioxide
and nitrogen oxides. During the past year, the
two countries have met to discuss a variety of
topics related to emission inventories, includ-
ing the production of a 1990 inventory,
integration of Canadian and US. emission
data in the US. Air Information Retrieval Sys-
tem (AIRS), and projections of future
emissions. They have agreed to meet every
six months on a continuing basis to carry out
their work pursuant to the Agreement.
Canadian and U.S. SQz and NOx emis-
sions data for the years 1980 and 1985 and
preliminary estimates for 1990 are in-
cluded in Tables 2 and 3.
ATMOSPHERIC MODELING
In Annex 2 of the Air Quality Agree-
ment, Canada and the United States
agreed to exchange information with re-
spect to their development and refinement
of atmospheric models for purposes of de-
termining source-receptor relationships
and transboundary transport and deposi-
tion of air pollutants. In this report, results
from linear (Lagrangian) and complex
TABLE 2. Cana<
CANADA
Utility
Industrial
Other
Total
UNITED STATES
Utility
Industrial
Other
Total
ia/U.S. SOa Emission Estimates (106 tonnes/ tons/year)
1980
Millions of
tonnes
0.8
3.6
0.3
4.7
Millions of
tons
0.9
4.0
0.3
5.2
1985
Millions of
tonnes
0.7
2.8
0.2
3.7
Millions of
tons
0.8
3.1
0.2
4.1
19901
Millions of
tonnes
0.8
2.8
0.1
3.7
Millions of
tons
0.9
3.1
0.1
4.1
—••.,,.;:..;.. 1980 • .... : .-..
Millions of
tonnes
15.5
6.2
1.7
23.4
Millions of
tons
17.0
6.8
1.9
25.7
1985
Millions of
tonnes
14.2
5.4
1.5
23.1
Millions of
tons
15.6
5.9
1.7
23.2
19901
Millions of
tonnes
14.2
5.4
1.6
21.2
Millions of
tons
15.6
5.9
1.8
23.3
1 - Preliminary.
References:
U.S. Data - National Air Pollutant Emission Estimates, 1940-1990 (EPA-450/4-91-02, November 1991).
Canadian Data - Development of the 1980 NAPAP Emissions Inventory (EPA/600 /7-86/-57a, December 1986).
The 1985 NAPAP Emissions Inventory (Version 2): Development of the Annual Data and Modelers Tapes (EPA-600/7-89-012a,
November 1989).
29
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TABLE 3. Annual NC
(106 tonnes/ tons/year
CANADA
Utility
Industrial
Mobile2
Other
Total
UNITED STATES
Utility
Industrial
Mobile2
Other
Total
)x Emission Estimates for Canada and the United States
1980
Millions of
tonnes
0.2
0.4
0.6
0.6
1.8
Millions of
tons
0.2
0.4
0.7
0.7
2.0
1985
Millions of
tonnes
0.3
0.4
0.8
0.4
1.9
Millions of
tons
0.3
0.4
0.9
0.5
2.1
i 19901
Millions of
tonnes
0.3
0.4
0.7
0.5
1.9
Millions of
tons
0.3
0.4
0.8
0.6
2.1
1980
Millions of
tonnes
6.4
3.8
7.9
2.8
20.9
Millions of
tons
7.0
4.2
8.7
3.1
23.0
1985
Millions of
tonnes
6.7
3.4
7.0
2.8
19.9
Millions of
tons
7.4
3.7
7.7
3.1
21.9
i 19901
Millions of
tonnes
7.3
3.9
5.6
2.8
19.6
Millions of
tons
8.0
4.3
6.2
3.1
21.6
1 - Preliminary.
2 - Mobile - The United States has only highway vehicles - other transportation categories are included
under other; Canada has all transportation categories included under mobile.
References:
U5. Data -National Air Pollutant Emission Estimates, 1940-1990 (EPA-450/4-91-02, November 1991).
Canadian Data - Development of the 1980 NAPAP Emissions Inventory (EPA/600/7-86/-57a. December 1986).
The 1985 NAPAP Emissions Inventory (Version 2): Development of the Annual Data and Modelers Tapes (EPA-600/7-89-012a,
November 1989).
non-linear (Eulerian) models used in the
assessment of acidic deposition and pro-
gress in the evaluation of Eulerian models
arc presented.
In the sections that follow, the following
are discussed: atmospheric model applica-
tion, atmospheric model evaluation, and
atmospheric model development.
Atmospheric Model Application
Canada and the United States have de-
veloped strong acid deposition modeling
programs over the past several years and
are in a good position to meet the objec-
tives of the Air Quality Agreement.
Models are used to characterize regional
source-receptor relationships, including those
of the transboundary transport of pollutants.
Efforts are under way to exchange informa-
tion on the use of atmospheric models to
augment monitoring data. The augmenta-
tion of data also is intended to help
provide more timely estimates of atmos-
pheric deposition and air quality for the
assessment of current and estimation of fu-
ture ecological effects. Information also is
30
-------
Figure 2a
Wet SO4 deposition data 1982-1986 (kg/ha/yr). Current conditions—the
observed 5-year (1982-1986) mean deposition values.
being exchanged regarding the use of at-
mospheric models to anticipate trends in
air and precipitation concentrations that
would be expected in the annual and sea-
sonal time series from the monitoring data.
Atmospheric models have played an
important role in assessment and applica-
tion studies in both countries. A major
assessment effort by Canada was com-
pleted in 1990; the results were published
in the "1990 Canadian Long-Range Trans-
port of Air Pollutants and Acid Deposition
Assessment" report. Canadian estimates of
current and future wet sulphate deposi-
tion, assuming full U.S. and Canadian
control programs, are shown in Figure 2.
The Canadian analysis, which was based
on the Ontario Ministry of the Environ-
ment's long-range transport model, shows
that, when the control programs in both
countries are fully implemented, wet sul-
phate deposition for the most part will be
less than 20 kg/ha/year in the acid-sensi-
tive regions of Eastern Canada. In the
United States, atmospheric models used in
the 1990 NAPAP Integrated Assessment
were described in a 1989 NAPAP publica-
tion with applications and performance
evaluation status, ("Models Planned for
Use in the NAPAP Integrated Assess-
ment"). U.S. estimates of current, future, and
relative (percentage change) wet sulphate
deposition, assuming full implementation of
U.S. and Canadian control programs, are
shown in Figure 3.
Efforts have begun under the Agree-
ment to identify and resolve differences in
the details of the estimates of current and
projected wet sulphate deposition from the
respective assessments. Additional efforts predictions of deposition under conditions of full implementation of
also have begun to study and extend the the S°2 C0ntr°l Pr°8mm in Eastern Canada and a 10 million ton (9 million
wet deposition estimates to total sulphate metnc tmms) reduction in 198° emissions in the United States.
Figure 2b
31
-------
Wei sulphate deposition for 1982-85 (kg/ha) from monitoring
sites (imlh smoothing-kriging).
RADM. wet sulphate deposition for 1982-85 (kg/ha) from
monitoring sites (with smoothing-kriging).
deposited. This coordinated review is ex-
pected to result in a consistent assessment
of the effect of the combined Canadian and
U.S. control programs on air quality and
deposition. Efforts also have begun to de-
velop a common approach to the best use
of the different atmospheric modeling
tools for assessment purposes.
Planning is under way between EPA and
Canadian federal and provincial agencies to
exchange atmospheric model estimates of
the transboundary effect of SOa emission
controls in both countries on sulphate
deposition reductions in Canada and the
United States, respectively.
In the near future, information will be
exchanged on atmospheric model esti-
mates of nitrogen deposition. This work
will augment continuing efforts related to
wet sulphate, dry sulphur dioxide deposi-
tion, and sulphate air concentrations.
Atmospheric Model Evaluation
The two countries have been cooperat-
ing in a multi-year, bi-national Eulerian
Model Evaluation Field Study (EMEFS)
since 1985. The Preliminary EMEFS Evalu-
ation of the advanced acidic deposition
models developed in the two countries,
the Regional Acid Deposition Model
(RADM) in the United States and the Acid
Deposition and Oxidant Model (ADOM)
in Canada, has been completed. Results for
RADM were presented in the NAPAP
State of Science and Technology Report
No. 5. Improvements to both ADOM and
RADM stemming from the findings of the
preliminary evaluation have been com-
pleted in 1991. The large under-prediction
32
-------
kg - SO4/ha
0-10
10-20
20-30
30-40
kg - SOWha
0-10
I I 10-20
20-30
>30
RADM wet sulphate deposition for 1982-85 (kg/ha).
RADM wet sulphate deposition for 2010 (kg/ha).
of sulphate deposition in the earlier ver-
sions' predictions has been virtually
eliminated for both models.
Phase 1 of the EMEFS program will be
completed in 1992. Two joint workshops
were held in 1991 to exchange and discuss
model evaluation results. Diagnostic prob-
ing of the ADOM and RADM models will
continue to be jointly coordinated through
the EMEFS process. This diagnostic analy-
sis is based on comparisons against special
Canadian and U.S. aircraft and surface
measurements collected under EMEFS.
Plans for the cooperative work of Phase
2 of the bi-national EMEFS evaluation
have been developed and priorities for
specific test periods established. Phase 2 is
expected to continue through 1993. The
emphasis of the RADM and ADOM evalu-
ation is expected to shift from sulphur to
nitrogen and ozone. Although several of
the key issues regarding sulphur have been
successfully dealt with in the improvements
stemming from the Preliminary and Phase 1
evaluation work, sulphur predictions will
continue to be examined because of the im-
portance of sulphur in the Air Quality
Agreement.
Cooperative work on the evaluation of
the atmospheric models will be expanded
under the Agreement to include the
evaluation of models used to estimate sea-
sonal and annual averages of sulphur
deposition and ambient sulphate concen-
trations for assessment purposes.
33
-------
Atmospheric Model Development
Longer range plans for model develop-
ment also are being coordinated with
bi-national participation. A North American
Consortium on Advanced Modeling of Re-
gional Air Quality (CAMRAQ) is a major
vehicle for this coordination and informa-
tion exchange. CAMRAQ includes several
industrial research organizations as well as
federal, provincial, and state agencies. The
model development efforts will set a high
priority on the extension of acid deposition
models to incorporate regional particu-
lates. Explicit inclusion of particulates will
produce atmospheric models that give a
more accurate assessment of visibility pro-
tection and air quality deterioration. This
development effort will directly support
visibility protection efforts called for in the
Agreement.
Wei deposition
monitoring site.
DEPOSITION AND AIR
CONCENTRATION MONITORING
NETWORKS AND RESULTS
In Annex 2 of the Air Quality Agree-
ment, Canada and the United States have
agreed to coordinate their air pollutant
monitoring activities for the purpose of de-
termining and reporting on air pollutant
concentrations and deposition. Since the
deposition of sulphur and nitrogen com-
pounds is linked to both acidic deposition
and acidifying emissions, it is the focus of
the discussion in this section. The simple
measure of acidity, pH, offers a limited ap-
preciation of the deposition phenomenon
and is therefore not used in this discussion.
Acid deposition is traditionally consid-
ered in terms of wet and dry components.
Wet deposition is the product of the con-
34
-------
centration of a species in precipitation and
the amount of precipitation. Trends in wet
deposition therefore reflect the trends in
both concentration and precipitation
amount. Sulphate and nitrate wet deposition
has been monitored intensively in Canada
and the United States throughout the 1980s
by federal, state, provincial, and industrial
monitoring networks, and results are re-
ported here.
Dry deposition is not amenable to such
monitoring methods. Moreover, studies are
hindered because cost-effective direct meas-
urement systems are not available. Dry
deposition is estimated in the United States
by the inferential approach for the 50-station
National Dry Deposition Network (NDDN)
and for the 9-station National Oceanic and
Atmospheric Administration (NOAA) re-
search network. In Canada, dry deposition is
determined at 11 sites using a similar ap-
proach. The inferential approach used to
calculate dry deposition in Canada and in
the United States determines deposition flux
as a product of measured concentration and
as a modeled deposition velocity based on
measurements of meteorological variables
and physical/biological surface conditions,
and provides relevant information at a rea-
sonable cost. Other approaches to measuring
dry deposition, such as eddy correlation,
throughfall, and gradient processes, are in the
exploratory phase of development. Al-
though the latter "direct" flux measure-
ments have not been used in routine moni-
toring programs, they are used at selected
sites in the United States for comparison to
inferential measurements.
Monitoring networks are important in the
context of the Air Quality Agreement. Spe-
cifically, data on the concentration and
deposition of acidic compounds and ozone
will be collected to:
• assess the effectiveness of emission re-
duction requirements;
m support aquatic and terrestrial effects
monitoring and research;
m determine regions of the continent at
risk;
m assess materials damage;
m perform model maintenance and
application;
m determine transboundary impacts; and
• support water quality determinations.
Environment Canada monitors wet and
dry deposition within the Canadian Air and
Precipitation Monitoring Network (CAP-
MoN). Most provincial Ministries of the
Environment in Canada also carry out wet
deposition monitoring. The combined fed-
eral and provincial wet deposition data are
archived centrally in the National Chemistry
Data Base (NATCHem).
As a result of the CAA, the United States
created the Clean Air Status and Trends Net-
work (CASTNET), which reflects a multi-
agency, multi-program approach to large-scale
monitoring and assessment. The participants in
CASTNET include federal and state agencies
and universities. The CASTNET program will
provide a means to coordinate with Canada
the monitoring of acid deposition and facili-
tate the exchange of information as agreed to
in the Air Quality Agreement.
In the United States, the existing Na-
tional Atmospheric Deposition Program/
National Trends Network (NADP/NTN)
Wet deposition data
from the largest and
most geographically
diverse of these
networks have been
combined to produce
maps showing the
spatial patterns of
wet deposition in
eastern North
America.
35
-------
Figure 4
1980 wet SO* deposition—sea salt corrected (kg/ha/y).
1984 wet SO* deposition—sea salt corrected (kg/ha/y).
'.988 wet SO* deposition—sea salt corrected (kg/ha/y).
will be relied upon to provide the basic
framework for the wet deposition moni-
toring data. The CASTNET program will
place additional wet and dry deposition
monitoring sites in areas of the United
States that are currently under repre-
sented. These areas include sensitive
ecosystems, such as high elevation sites
and coastal regions. The expanded NDDN
(CASTNET), NOAA network, and the
NADP/NTN will provide weekly total ni-
trogen and sulphur deposition, ozone, and
sulphur dioxide concentration data. These
data will be combined with data from the Ca-
nadian networks to estimate the spatial
patterns of total deposition across North
America.
In the United States, a number of sta-
tions offering detailed daily measures of
wet and dry deposition parameters will be
operated by NOAA under their new At-
mospheric Integrated Research Monitoring
Network (AIRMoN). This network is de-
signed to provide a timely indication of
the localized effects of emission controls
on the atmosphere and on deposition from
it, for a smaller number of sites selected to
reveal the consequences of controls in
some areas of special interest.
Wet deposition data from the largest and
most geographically diverse of these net-
works have been combined to produce
maps showing the spatial patterns of wet
deposition in eastern North America. Figure
4 shows the annual wet deposition distri-
butions of sulphate (corrected for sea salt
within 100 km of the ocean) across eastern
North America for the years 1980, 1984,
and 1988. Figure 5 shows the correspond-
36
-------
ing distributions of nitrate. The annual
patterns (separated by 4-year intervals)
provide a useful baseline for assessing
possible spatial and temporal changes
throughout the 1980s and future changes
in the patterns. It is worth noting that the
patterns represent regional-scale deposi-
tion and are based on measurements taken
away from large emission sources.
Deposition monitoring, like atmos-
pheric model development and the
production of emission inventories, is an
evolutionary process. Refinements in the
collection and analysis of data have led to
continuing improvements in the produc-
tion of deposition maps, and future work
will lead to even more improvements.
Air concentration and dry deposition of
sulphate and nitrate have not been moni-
tored in the United States and Canada to
the extent that wet deposition has been.
Figure 6 shows the existing air concentra-
tion and dry deposition monitoring sites
and displays median SO2 air concentration
values recorded in 1989 at these sites in the
United States and Canada. The map shows
that relatively higher levels (generally
above 10 |o.g/m ) of SO2 were found in a
roughly rectangular area bounded by
southern New York, northern Virginia,
central Illinois, and northern Illinois. Con-
centrations generally decline as one moves
away from this region. The concentration
data are used to calculate dry deposition
using the inferential approach.
The values in Figure 6 should be
viewed as snapshots; they represent data
only from 1989, and are the products of
two different sampling time periods. The
Canadian sites monitor on a daily basis,
Figure 5
1980 wet NO3 deposition (kg/ha/y).
1984 wet NO3 deposition (kg/ha/y).
1988 wet NOs deposition (kg/ha/y).
37
-------
Figure 6
• NDDN
• NOAA
A CAPMON
• NDDN and NOAA
T NDDN, NOAA
and CAPMON
Median 1989 SOz air concentrations (\igfnf) at CAPMoN and NDDN sites. At Penn State, the CAPMoN value appears
above the NDDN values.
while the U.S. sites operate on a weekly
schedule. These different sampling periods
could lead to systematic differences in the
data reported by the networks. However,
at Pennsylvania State University, Cana-
dian and U.S. sampling instruments
operate within about 15 km of each other.
The maps for 1989 indicate that, for the an-
nual medians at least, the networks' data
are comparable. Actual dry deposition
fluxes have not been calculated from the
air concentration data for the 1989 moni-
toring period. The patterns for dry
deposition could be substantially different
than those for the air concentrations.
Figures 7 and 8 are simple bar charts of
annual wet deposition of sulphate and ni-
trate, respectively, at seven sites across
North America. It is apparent from these
figures that annual wet deposition is
highly variable on a year-to-year and site-
to-site basis. This variability is related not
only to annual variations in emissions, but
also to variations in meteorology—espe-
cially wind and precipitation patterns. As
a result, it is entirely possible for emissions
to remain roughly constant over several
years while the deposition varies consider-
ably. This natural variability has major
implications on the length of time required
to detect long-term trends in deposition.
38
-------
Figure?
ELA
Kejimkujik
80 81 82 83 84 85 86 87
Annual wet deposition of sea salt corrected sulphate (kg h y ) at four CAPMoN sites in Canada
and three NADP/NTN sites in the United States.
Figure 8
ELA
Kejimkujik
80 81 82 83 84 85 86 87
Annual wet deposition of nitrate (kg h' y' ) at four CAPMoN sites in Canada and three
NADP/NTN sites in the United States.
39
-------
A strong correlation
supports the
hypothesis that
sulphate deposition
has Itad a direct effect
on the chemistry of
surface wafers in
many parts of North
America.
US. and Canadian scientists are currently
working on a common trends analysis ap-
proach for both countries.
In Canada, trends in concentration data
for sulphate and nitrate in precipitation
have been analyzed at five CAPMoN sites.
The trends were determined using CAP-
MoN data in a best-fit time series model
that accounted for inherent seasonal cy-
cles, long-term cycles, long-term trends,
and the relationship between precipitation
depth and concentration. The relationship
between the modeled and calculated
means is quite good.
Sulphate in precipitation at the Cana-
dian sites generally decreased from the
early to late 1980s (roughly 1986-1987), af-
ter which time it stayed approximately
constant to 1990. In contrast, nitrate con-
centrations showed no significant trend
upward or downward at three of the five
sites, increased dramatically from 1981
through 1990 at the fourth site, and cycled
through a decrease and an increase at the
fifth site. It remains for researchers to es-
tablish the linkage between these trends
and trends in emissions and meteorology.
The goal is to be able to describe total
sulphur deposition. Research is currently
ongoing so that wet and dry deposition
fluxes in kg/ha can be combined to give
total deposition.
In Annex 2 of the Air Quality Agree-
ment, Canada and the United States
agreed to cooperate and exchange infor-
mation with respect to (a) their monitoring
of the effects of changes in air pollutant
concentrations and deposition with re-
spect to changes in various effects catego-
ries, and (b) their determination of any
effects of atmospheric pollution on human
health and ecosystems. In the following
sections, the effects of acidic deposition on
aquatic systems, forests, human health,
and materials are discussed. Programs to
protect visibility were discussed in an ear-
lier section of this report.
It was the observations of aquatic ef-
fects in the 1970s that initiated the
widespread scientific and political interest
in acidic deposition. Because research be-
gan relatively early, understanding the
impact of acidic deposition on aquatic re-
sources is in many ways more developed
than for other ecosystem components.
Terrain Sensitivity and Regions of
Concern
Canada
Approximately 4 million km2 (43 per-
cent of Canada's land area) is considered
potentially sensitive to changes in chemis-
try and biology as a result of changes in
acidic deposition chemistry. These sensi-
tive areas correspond, to a major degree, to
the Canadian Shield. The coincidence of
sensitive terrain and elevated acidic depo-
sition defines the area of primary concern.
In Canada, it is restricted to the southeast-
ern portion of the country (Figure 9).
United States
Those areas where lakes and streams
would be expected to change in response to
changes in sulphur and nitrogen deposition
are New England, the Adirondacks, the
Mid-Atlantic Highlands, the Mid-Atlantic
Coastal Plain, the Southeastern Highlands,
-------
Florida, the upper Midwest, and portions
of the West (Figure 9).
Sulphate Deposition versus Surface
Water Concentrations
Sulphate concentrations in many dilute
surface waters are controlled by the magni-
tude of sulphur deposition. A plot of median
regional wet sulphate deposition versus me-
dian surface water sulphate concentration
yields a positive relationship (Figure 10). Ex-
ceptions are easily explained such as regions
receiving high dry deposition (e.g., Sud-
bury), or regions having sulphate-absorbing
soils (e.g., Southeastern Highlands). The
relatively small scatter of the remaining
points in Figure 10 reflects regional differ-
ences in the relative magnitude of wet and
dry deposition, climate geological sources of
sulphate, terrain physiography, and other
system variables.
The strong correlation evident in Figure
10 supports the hypothesis that sulphate
deposition has had a direct effect on the
chemistry of surface waters in many parts of
North America. Surface waters react to the
increased sulphate in one or more of the fol-
lowing ways: decreasing acid neutralizing
Figure 9
LAB
WEST
United States Regions
NE - New England
ADR - Adirondacks
UMW -UpperMidwest
MAH - Mid-Atlantic Highlands
MAC - Mid-Atlantic Coastal Plain
SEH - Southeastern Highlands
FLA - Florida
WEST -West
Canadian Regions
ONT - Ontario
QUE -Quebec
LAB - Labrador
NF - Newfoundland
NB - New Brunswick
NS - Nova Scotia
Location of Canadian and United States regions of concern. Markers indicate general location of
region rather than specific points. More regions are indicated than discussed specifically in the text.
Data for all regions listed are available for assessment of change.
41
-------
Can. Lakes
U.S. Lakes
U.S. Streams
Figure 10
i
Sj 200 —
§
2 150 —
O
O
o
O 100 —
O
CO
eW 50 —
"O
0)
2
(
High dry o
deposition ** -*
• "
• a
m •
• m
Jfm-^
•• p i m
•Tt ™ .^^^ J
• •" ^^^^ - B S04
^" r_^ r-* adsorbing
• ^"^^^CTi • — regions
1 1 1 1 1 1
3 5 10 15 20 25 30 3
Wet SO4 Deposition (kg/ha/yr)
5
Relationship between median sulphate concentrations in lakes and wet sulphate deposition.
capacity (ANC) and pH, increasing base
cations, and/or decreasing organic anions.
Surface waters with an ANC 5 0 n.eq/L
are defined as acidic, while those with ANC
£ 50 fieq/L are defined as extremely sensi-
tive to acidification. In addition to the
influence of sulphate deposition, the ANC
of surface waters can increase with in-
creasing base cations and/or decreasing
organic anions.
Current Chemical Conditions in
Regions of Concern
Canada
Lakes in the Atlantic provinces of Can-
ada and Quebec generally have lower base
cation and ANC concentrations than those
in Ontario primarily due to differing ter-
rain geology. Thus, lakes in the Atlantic
and Quebec regions are typically more
sensitive to acidic deposition than lakes in
either Ontario or the eastern United States.
The Sudbury region in Ontario also has
acidic lakes localized around a large emit-
ter of sulphur dioxide. There are in the
order of > 14,000 acidic lakes >1 ha in size
and > 31,000 acidic lakes > 0.18 ha in size in
southeastern Canada. Regional acidification
of eastern Canadian lakes is primarily due to
sulphate deposition, not organic acids.
United States
Within the regions shown on Figure 9,8
percent of the streams and 4 percent of the
42
-------
lakes were acidic and about 20 percent of
both lakes and streams had ANC below 50
H.eq/L. Florida had the highest proportion
of acidic surface waters among the Na-
tional Surface Water Survey (NSWS)
regions (39 percent of the streams and 23
percent of the lakes), followed by the Adi-
rondacks (14 percent of lakes) and the
Mid-Atlantic Coastal Plain (12 percent of
streams). The remaining regions have < 10
percent acidic surface waters and the west-
ern United States and the Southeastern
Highlands have < 1 percent. Organic acids
and sulphate from acid mine drainage sig-
nificantly contribute to the acidification of
waters in some areas, particularly Florida
(organics) and the mid-Appalachians (acid
mine drainage). However, atmospherically
deposited sulphate is the dominant anion
in 75 percent of the acidic lakes and almost
50 percent of the acidic streams. Overall,
there were 1,180 acidic (ANC<0) lakes
larger than 4 ha and 4,520 acidic streams in
the assessed regions, representing an acidic
lake area of 263 km2 and 7,900 km of acidic
stream length.
The above assessments reflect average
conditions. Acidic deposition contributes
to episodic depressions of ANC that occur
during high flow periods associated with
rainstorms and snowmelt. When these epi-
sodes are taken into account, the number
of acidic lakes and streams in many areas
will increase up to threefold (including areas
of the western United States).
Differences in the chemical variability of
U.S. and Canadian surface waters are
largely due to much greater geological di-
versity in the United States.
Current Conditions:
Biological Response
Acidification of aquatic ecosystems causes
adverse effects on many aquatic organisms.
A direct effect is the toxicity of hydrogen ion,
which can be accentuated if calcium concen-
trations are low. Toxic concentrations of
aluminum occur in many chronically or epi-
sodically acidified surface waters as well.
Indirect effects of acidification are usually
changes in organisms caused by interactions
43
-------
with other directly impacted organisms, e.g.,
starvation through disappearance of other
food organisms.
Damage to fish populations often be-
gins to occur when pH<6.0. Minnow
species and other smaller fishes are fre-
quently more sensitive than many sport
fishes. Successful reproduction can occur
in formerly non-reproducing populations
by reversing acidification.
Applications of fish response models
suggest that U.S. waters having acid-base
chemistry unsuitable for the survival of
acid-sensitive fish species range from < 5
percent in areas such as the Upper Mid-
west to near 60 percent for upper stream
reaches in the Mid-Atlantic Coastal Plain.
Brook trout is one of the species most widely
distributed in waters sensitive to acidic
deposition and is also an important sport
fish in these regions. An estimated 13 to 14
percent of the NSWS lakes in the Adiron-
dacks classified as potential brook trout
habitat currently have acid-base chemistry
unsuitable for brook trout survival.
Case Studies: Canada and the
United States
Ontario
The chemical condition of surface wa-
ters can improve under decreased sulphur
deposition. An illustrative case is the sur-
face waters near Sudbury, Ontario.
Sulphur dioxide emissions from the smelt-
ers at Sudbury, in central Ontario, declined
from about 2.2 x 106 tonnes in 1950 to 1972
to about 0.6 x 106 tonnes by 1979 to 1985.
Due to the replacement of short stacks by a
single tall stack (1972), local deposition has
decreased by as much as 75 percent. Sev-
eral lakes near Sudbury have shown
substantial decreases in lake water sul-
phate; increases in pH; and decreases in
Al, Cu, Ni, and Zn. Since 1986, the sul-
phate and pH trends in Sudbury area lakes
have stabilized. These changes in sulphate
and pH also were found in lakes outside
the immediate influence of the smelters.
The decrease in SOa emissions at Sudbury
has resulted in a rapid reversal of chemical
acidification. However, evidence for the
reversal of biological effects is less exten-
sive, e.g., trout populations in a few lakes
relatively remote from the smelters have
responded positively to an increase in pH.
The Algoma area of central Ontario lies
west of and outside the direct influence of the
Sudbury smelters. Lakes in Algoma respond
rapidly to changes in reduced sulphate
deposition with either increased pH and
ANC or decreased base cations. Two lakes
without fish in 1979 developed white
sucker populations by 1986 through inva-
sion from downstream populations when
lake pH approached 5.5.
Plastic Lake is a sensitive lake in south-
central Ontario. ANC decreased in Plastic
Lake between 1979 and 1985 by about 2
H-eq-L^yr'1. There was a contemporaneous
pH and base cation decline, but no signifi-
cant change in sulphate. Dissolved organic
carbon also decreased and water transpar-
ency increased as the lake became more
acidic. Major biological changes also oc-
curred in Plastic Lake, although the pH
decreased only from 5.8 to 5.6. It is likely
that 75 to 80 percent of the original ANC of
Plastic Lake may have been lost before
studies began in 1979. Since 1985, the pH
and ANC of Plastic Lake have remained
constant despite a sharp decrease in sul-
phate and H+ deposition in southern
Ontario in the past decade. This is ex-
44
-------
plained by continuing release of sulphate
and acidity previously stored in wetland
areas in the catchment.
Nova Scotia
One-third of the available Atlantic
salmon habitat in Nova Scotia has been
lost due to acidification since 1950. In Nova
Scotian rivers with pH>5.0, juvenile At-
lantic salmon are present at population
densities which are normal for the region
(20 to 30 fish/100 m). No juveniles are
found in rivers with pH < 5.0 except those
that have some tributaries with higher pH.
Liming of headwater lakes may be used in
some cases to achieve a short-term restora-
tion of acidified salmon habitat in Nova
Scotia. The limed lakes release ANC to the
downstream habitat. The major disadvan-
tage is that most Nova Scotian lakes have a
turnover time of less than one year, hence
annual reapplication of lime is required.
Adirondack Mountains
The chemistry of 16 lakes has been
monitored since 1982. Most lakes exhibit
decreasing sulphate concentrations consis-
tent with decreases in sulphur deposition
in the 1980s; however, increasing lake
water nitrate levels could not be attributed
to change in deposition. None of the Adi-
rondack lakes exhibit the increase in ANC
expected from a decrease in sulphate; in
fact, ANC declined in four lakes. Increases
in nitrate and uncertainty in the trends for
base cations and aluminum confound the
simple expectation that ANC will increase
as sulphate concentrations decrease in Adi-
rondack lakes.
Catskill Mountains
The Catskill Mountains are in a high
deposition region of southern New York
where streams are the primary aquatic re-
source; eight streams have been monitored
there since 1983. Other source water
streams for the New York City water sup-
ply have data records extending back to
1915. Catskill streams show large short-term
variability, long-term decreases in sulphate
and increases in nitrate, and little overall
trend in ANC or pH. Sulphate concentra-
tions have been decreasing since circa 1970,
consistent with the timing of maximal sul-
phur deposition in the northeastern United
States, while nitrate concentrations have
been increasing since circa 1970.
FORESTS
Large areas of forests in the United
States and Canada are routinely exposed
to acidic deposition, sulphur dioxide, ox-
ides of nitrogen, and other pollutants.
There is general agreement that the major-
ity of forests in North America are not
extensively affected by acidic deposition.
In the east, only certain tree species in ar-
eas receiving the highest load of pollutants
via fog or clouds are experiencing damage.
The North American
Maple Project
The North American Maple Project
(NAMP) was implemented under a Memo-
randum of Understanding between
Forestry Canada and the U.S. Department
of Agriculture (USDA), with significant
collaboration of agencies at the provincial
and state level.
The purpose of NAMP was to deter-
mine the rate of change in sugar maple
condition over time. A network of 166 five-
plot clusters was established in 84 active
sugarbushes (tapped stands) and in 82 un-
managed, natural stands in Canada and in
45
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Figure 11
A Non-sugarbush NAMP Stand
• Sugarbush NAMP Stand
Note: Locations approximate. Indicate distribution only.
Distribution of plot clusters for the North American Maple Project (1988/1989).
the United States from Wisconsin in the
west to Nova Scotia in the east (Figure 11).
In 1990, 93 percent of sugar maples were
found to be in a healthy condition. Only 7
percent of sugar maples evaluated had 20
percent or more crown dieback. There was
no significant difference between crown
condition in sugarbushes versus unmanaged
forest stands. There was no relationship be-
tween crown condition and wet sulphate
deposition. Natural causes such as drought
and abnormal winters appear to be the
most likely causes of sugar maple decline
although the role of acidic deposition and
ozone as predisposing factors cannot be
ruled out at this time.
Current State of Forests
Canada
The health of Canada's forests has been
monitored nationally since 1984 by the Acid
Rain National Early Warning System
(ARNEWS). A common set of measure-
ments is used at 103 permanent sample plots
located in all 10 provinces to detect early
signs of air pollution damage in Canada's
forests.
Data on tree mortality and crown condi-
tion for 16 conifers and 9 hardwoods indi-
cate that there is no evidence of a national
decline in Canadian forest health. With the
exception of white birch in southern New
46
-------
Brunswick, tree mortality was within "nor-
mal" ranges (1 to 3 percent) and was attrib-
uted to natural stresses. Balsam fir
mortality in Eastern Canada exceeded 3
percent due to the spruce budworm.
No sugar maple mortality was recorded
by ARNEWS in the Maritimes. Sugar maple
mortality was 1 percent annually in Quebec
and 3 percent annually in Ontario. In some
localized areas, mortality reached 25 percent
in certain years. The general crown condi-
tion of sugar maples declined in Ontario be-
tween 1986 and 1990. This was attributed to
severe drought conditions.
Mortality of white birch in southwest-
ern New Brunswick was 11 percent be-
tween 1982 and 1990. Air pollutants are
implicated as contributing factors predis-
posing white birch to decline.
United States
In 1990 the U.S. Forest Service, with
EPA and state forestry agencies, initiated a
National Forest Health Monitoring Pro-
gram. Currently, the program is opera-
tional in 10 eastern and 2 western states,
with data collected from over 1,000 perma-
nently established plots. Initial results for
the six New England states in 1990
showed the forests to be in generally
healthy condition, with no unknown
health problems. The National Forest
Health Monitoring Program is designed to
be fully compatible with the Canadian
ARNEWS.
There is no evidence of an overall or
pervasive decline in forests in the United
States, due to acidic deposition or any
other stress factor. Moreover, there is no
case of forest decline in which acidic depo-
sition is known to be a predominant cause.
Only in cases where forests are frequently
exposed to highly acidic fog or cloud
water is there evidence that acidic deposi-
tion is a significant contributing factor to
observed forest health problems. Research
continues to assess the interactive effects
involving air pollution and drought, pest
infestation, and other stress factors.
The USDA Forest Service has reported
widespread reductions in average tree
growth rates within diameter classes in
natural pine stands in the Southeast. Simi-
lar growth rate reductions have not been
observed in plantations. Occurrence of the
reported tree growth reductions in natural
pine stands is an expected consequence of
historical land use patterns, increases in
stand age and competition, and other
natural factors. However, data analyses
constructed to date have not determined
whether the tree growth reductions are
greater or less than would be expected in
the absence of acidic deposition and asso-
ciated pollutants.
Efforts to evaluate pine growth trends
at the stand level have identified unex-
plained variation but have been severely
47
-------
limited by the nature of the available data.
Whether acidic deposition or other air
quality factors are significantly affecting
the health and productivity of southern
pines remains to be determined. A survey
of visible symptoms of stress indicated
that the crowns of most southern pine
trees are healthy. However, ambient levels
of ozone have altered seedling growth and
physiology of some pine families in con-
trolled experiments.
Effects of acidity on above-ground pine
tissue in controlled experiments are gener-
ally non-significant. Available evidence
does not support the hypothesis that acidic
deposition has caused aluminum toxicity
or nutrient deficiencies in southern pines.
Ozone stress is the predominant factor
in a decline of ponderosa and Jeffrey pines
in the San Bernardino Mountains near Los
Angeles and in part of the Sierra Nevada
Mountains. Ozone also may be contribut-
ing to red spruce decline at high elevations
and is causing visible injury to foliage on
sensitive genotypes of eastern white pine,
black cherry, and many other species.
The extent to which ozone is affecting for-
est productivity and ecosystem diversity re-
mains to be determined. Experiments with
seedlings have shown that many species
across the United States have genotypes that
are adversely affected by ambient levels of
ozone. It is difficult to extrapolate confi-
dently the experimental results, because ma-
ture trees in forest stands may respond to
ozone differently than seedlings grown un-
der experimental conditions. In areas out-
side the Los Angeles Basin, effects of
ambient ozone on tree species have not
been shown to cause forest health prob-
lems other than visible injury and growth
loss in sensitive individual trees.
Ecosystems/Watersheds/Soils
The flux of SO4/NO3 from the atmos-
phere through the forest ecosystem to
aquatic ecosystems has been monitored and
studied intensively at a number of calibrated
watersheds. In northeastern North America,
six such watersheds have been operating for
different periods of time. Data have helped
demonstrate that controlling emissions to re-
duce SO4 deposition may reduce SO4
leaching from podzolic soils. This suggests
that the deposition of strong mineral acids is
contributing to the leaching of base cations
from some Canadian soils. Over the long
term, this may reduce the fertility of some
soils.
Long-term changes in the chemistry of
some sensitive soils is expected from acidic
deposition. It is uncertain whether this will
result in reduced forest health, how much
of the forest resource will be impacted, or
how long it will take to occur. Modeling
studies suggest that acidic deposition
could have measurable effects on the
chemistry of some southern U.S. soils
within 50 years. Whether such changes
will actually occur or affect forest growth
remains to be determined. Beneficial ef-
fects on soil fertility due to nitrogen
deposition may offset adverse effects due
to accelerated leaching of base cations in
the short term, followed by long-term de-
creases in nutrient status of the soils.
48
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Individual Forestry Case Studies
Coastal Fog and Tree Decline at
Low Elevations
Two tree species growing along coastal
regions of eastern North America have
been in decline since the early 1980s. His-
torical evidence indicates that there have
been increases in fog acidity (five- to ten-
fold) and NOs concentrations since 1939,
but no change in SO*. Compared with
mountain cloud chemistry in the North-
east, these coastal fogs are up to three
times higher in the ionic concentrations
and lower in pH.
Foliar decline symptoms have been ob-
served on red spruce trees growing at a mid-
coast site in Maine where acidic deposition
in fog is greatest. Foliar browning and leaf
fall early in the season have been observed
on white birches in coastal southwestern
New Brunswick since 1979. Insects and
pathogens have been discounted as causal
agents. The area has recently experienced
high fog frequencies during the summer.
Studies have demonstrated a relationship
between hydrogen and NOs concentrations
in fog and incidence of foliar browning.
The condition of white birch deterio-
rated markedly between 1982 and 1987
and then stabilized until 1990. In 1987, all
trees examined were exhibiting some de-
gree of decline. Twig and branch dieback
reached 50 percent by 1987. Mortality in-
creased to 11 percent in 1990 (Figure 12).
Red Spruce Decline at High
Elevations
There is experimental evidence that acidic
deposition and associated pollutants can alter
the resistance of red spruce to winter injury;
Figure 12
100 —
1982 1983 1984 1985 1986 1987 1988 1989 1990
Year
No Dieback Twig Dieback
Twig and Branch Dieback
Dead
Birch decline.
through this mechanism, acidic deposition
may have contributed to red spruce de-
cline at high elevations in the northern Ap-
palachians. Evidence of red spruce decline
and pollutant involvement in the southern
Appalachians is less substantial.
Red spruce that grows in the cloud-ex-
posed forests of the northeastern U.S.
mountains has been declining for 30 years.
Repeated, severe winter injury was the pri-
mary inciting factor. With wind stress, in-
sect pests, and fungal pathogens, it has
served to sustain the decline.
Exposure-response experiments have
provided support for the hypothesis that
air pollution (particularly acids in cloud
49
-------
water) has a role in the decline. Some re-
sults with seedlings and branches of
mature trees indicate that airborne chemi-
cals at current levels can reduce the cold
tolerance of this species, which was al-
ready marginal in its ability to survive low
temperatures and other stresses. Other re-
sults with seedlings show that ambient or
near-ambient levels of acidic mist and
ozone can, under some conditions, cause
direct injury to needles and unfavorable al-
terations in biochemical and physiological
processes. At present, it is not clear which,
if any, of these effects are occurring in the
field.
The current condition of red spruce in
the southern Appalachians is not agreed
upon by all investigators. Localized mor-
tality has been reported, while more
extensive surveys suggest that recent mor-
tality has been low relative to mortality in
the North. At present, areas of agreement
are: (1) there was a deterioration of crown
condition in the late 1980s, and (2) there is
a recent decrease in growth at the highest
elevations. Ongoing research has focused
on the ability of acidic deposition to exac-
erbate nutritional stress through above-
and, especially, below-ground effects. At
present, there is little available evidence
suggesting that the condition of red spruce
in the southern Appalachians has deterio-
rated because of acid deposition and/or
associated pollutants.
Agriculture
Agricultural crops are exposed regu-
larly to acid deposition, sulphur dioxide,
and ozone over large areas of North Amer-
ica. Acid deposition and sulphur dioxide
have been shown in laboratory or field ex-
posure studies to have the potential at
higher than ambient doses to affect mar-
ketability, growth, and yield of a number
of important species.
There is general agreement that acidic
precipitation at current levels has not been
responsible for crop yield reductions on a
regional basis in Canada or in the United
States. There is, however, the potential for
foliar injury in southern California. Cur-
rent levels of NOx and SOz also do not
appear to be affecting agricultural produc-
tivity on a regional basis.
The greatest concern is the impact of
ozone on agricultural production in the
United States and in Canada. Research re-
sults indicate that, depending on species,
location, and exposure, yield reductions in
crops have ranged from 0 to 56 percent at
ambient ozone concentrations.
MATERIALS AND CULTURAL
RESOURCES
The effect of acidic deposition on vari-
ous materials has been a concern in both
countries. It is difficult to make general-
ized statements about acidic deposition
and materials damage because materials
are subject to a variety of stresses.
NAPAP concluded that pollution is
causing degradation of materials beyond
that associated with natural weathering.
Documented sensitive materials include
carbonate stone and galvanized steel. Car-
bonate stone has been used in many
cultural materials, like statues, monu-
ments, significant public buildings, and
gravestones, while galvanized steel is used
in a multitude of end-uses. Research under
NAPAP and other programs confirmed
that rates of metals corrosion and carbon-
ate stone dissolution are accelerated by dry
-------
and wet deposition of acids. For carbonate
stone and certain metals, such as galva-
nized steel, reactions with sulphur
dioxide, wet deposited acids, and natural
acidity from dissolved carbon dioxide all
contribute to stone erosion and metal cor-
rosion. Results from laboratory and field
experiments indicate that pH 4 may be a
critical level of acid exposure for marbles,
limestones, and bronzes. In addition to
wet deposition induced corrosion/erosion,
dry deposition reacts with stone surfaces
to form black crusts which disfigure the
surfaces and cause disintegration and spal-
ling of the stone. Similarly, the green
patina on bronzes in urban environments
is largely composed of copper sulphate
compounds.
Research has provided the quantitative
data that help define the contributions of
wet and dry acidic deposition (including
rainfall acidity caused by atmospheric
carbon dioxide) to the corrosion of galva-
nized steel and the erosion of carbonate
stone test samples under the ambient envi-
ronmental conditions at field exposure
sites. The separate effects of these environ-
mental variables have been expressed in
the form of dose-response functions for the
corrosion of galvanized steel and the
chemical erosion of carbonate stone.
Weathering effects on complex shapes
(sculpture, cornices, bridges) are far more
severe than for flat surfaces (walls, roofs,
test specimens). Laboratory experiments
and measurements at buildings and
monuments indicate that available dose-
response functions represent minimum
corrosion rates and minimum contributions
from deposition to weathering/corrosion.
However, to date, these dose-response func-
tions have not been validated to the extent
that they can be used to predict accurately
the incremental change to structural com-
ponents of those materials resulting from a
change in one of the important environ-
mental variables.
The fact that the corrosion depends on
more than just the effects of sulphur dioxide
indicates that a specified decrease in the sul-
phur dioxide level will not lead to the same
decrease in the corrosion/weathering.
Other materials that have been studied
and discussed in the NAPAP documents
include wood and painted surfaces. One
concern important to consumers is the im-
pact of acidic deposition on automotive
finishes. Damage in the form of spotting
has been observed in some laboratory
simulations, but comprehensive studies of
the effects of weathering and acidic pollut-
ants on automotive paints have not been
published. NAPAP-supported research
corroborated the fact that aluminum-flake
maintenance paints may be susceptible to
degradation caused by acidic deposition.
The uptake of SO2 for these paints is in-
creased relative to that of inert substrates
and some other paint formulations. Some
leaching of the aluminum in these paints
was detected in runoff studies. Based on
these results, automotive formulations
containing aluminum flake would also be
expected to have similar reactivity to
acidic deposition.
In some cases, preservation methods are
available to prevent environmental dam-
age to cultural materials, notably the use
of protective coatings for metals, such as
lacquers or wax. However, once severe
corrosion has occurred, it is difficult to re-
store the original luster of bronze
sculptures. Theoretically, all outdoor
51
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bronzes could be protected from corrosion
by expenditures of $10 to $100 million per
year in the United States. In contrast to
metal corrosion control, there are no gener-
ally accepted methods to prevent stone
decay accelerated by either wet or dry
deposition. For many non-cultural materi-
als, economic costs from materials
degradation involves factors such as serv-
ice-life cycle, maintenance practices, and
behavioral variables.
In the United States, the areas having
the largest numbers of cultural materials
coincide with the regions of highest acidic
deposition. Most of the nation's historic
battlefields, especially those with many
commemorative monuments, are located
east of the Mississippi River. It is estimated
that some 15 to 50 percent of historic stone
buildings are sensitive to attack by atmos-
pheric acids; 20,000 to 50,000 outdoor
monuments are exposed nationwide; and
about one-third of the approximately 100
million grave markers are made from acid-
sensitive materials.
HUMAN HEALTH
Due to the complexity of atmospheric
transformation processes involved in the
development of acidic aerosols, a wide ar-
ray of pollutants are involved, including
sulphur oxides, nitrogen oxides, volatile
organic compounds, ozone (Oa), and or-
ganic acids. Only the effects of acidic
aerosols will be discussed here. Major re-
views of these other pollutants are readily
available.
Health Effects
Acidic aerosols are acidic particles sus-
pended in a gas having a net acidity. As
such, they are complex mixtures having sub-
stantial geographic and temporal variability.
Understanding the health risk of acidic aero-
sols requires integration of knowledge of
exposure, susceptible sub-populations, and
exposure-response relationships. The cur-
rent primary concerns for health risks center
on acidic sulphates and the potential for
acute effects on the pulmonary function of
asthmatics, effects on clearance of particles
from the respiratory tract, an increased inci-
dence of acute bronchitis in children, and
suggestions of premature mortality in sen-
sitive populations. The sparsity of
information on other acidic species pre-
cludes their discussion, but indicates that
further research may be warranted.
Animal toxicology and human clinical
studies have shown that the potency rank-
ing of sulphate aerosols is HzSCU >
NH4SO4 > (NH4>2SO4. Therefore, most of
these controlled studies have used H2SO4.
These data suggest that hydrogen ion (H*)
is the species of concern and that the spe-
cific compound also has an influence. This
also implies that measurement of ambient
H+ alone will not be fully predictive of ef-
fects on a population. Animal studies,
correlated to some human studies, have
led to a hypothesis that chronic exposure
to H2SO4 may contribute to the develop-
ment of chronic bronchitis. Supporting
evidence in animals includes findings of
slowed mucociliary clearance and struc-
52
-------
tural alterations of the lung, some of which
persist after chronic exposure ceases. Re-
search with laboratory animals also has
demonstrated that H2SO4 can synergisti-
cally interact with OB and other particles.
Thus, other co-occurring pollutants can en-
hance the effects of acidic aerosols.
Controlled human exposure studies of
the acute effects of HfeSCU on pulmonary
function have provided varying concentra-
tion-response relationships, with differences
between studies perhaps reflecting differ-
ences in aerosols, exposure regimes, exercise
levels, and human subjects studied. Gener-
ally, healthy volunteers are not affected at
H2SO4 concentrations high above ambient
levels. Several (but not all) studies indicate
that asthmatics can be susceptible to expo-
sures from 100 to 1,000 ng/m3
Preliminary results using 68 Hg/m3
suggest that adolescent asthmatics are
more sensitive. There is further evidence
that concomitant exposure to other pollut-
ants such as SO2 (0.5 ppm) or Cb (0.12
ppm) may enhance the irritative bronchial
response to acidic aerosols. Acute expo-
sure to HaSQi also slows clearance of test
particles from the airways of healthy and
asthmatic humans. For example, a 1-hour
exposure to 100 |ig/m3 H2SO4 substan-
tially depressed clearance. This effect is of
concern since it implies that inhaled parti-
cles and natural debris that are normally
cleared by the respiratory tract may build
up. Although the evidence from clinical
studies is highly suggestive of adverse ef-
fects of acute HaSO4 exposures, it is
important to recognize that much remains
to be confirmed.
A recent study in Canada observed
small decreases in children's lung function
that occurred during times of high air pol-
lution. Acid levels reached a maximum of
about 50 n-g/m3 (1 hour average), and
ozone levels were as high as 143 ppb.
One Canadian study compared the respi-
ratory health of 7- to 12-year-old children
from two communities, one experiencing
high, and one experiencing low levels of
long-range transported air pollution. Chil-
dren in the community with higher levels
of pollution had statistically significant
lower levels of forced vital capacity and
forced expiratory volume. While it was not
possible to attribute the effect to a specific
pollutant, it is noted that the two commu-
nities differed far more in their sulphate
exposures than they did in other measures
of pollutants. In a second Canadian study,
the health comparison was conducted in a
total of 10 communities, and it also demon-
strated a small but statistically significant
decrement in the same lung functions. Chil-
dren in the more polluted area also had a
higher incidence of upper respiratory in-
fections. It is believed that the observed
difference is likely due to the coexistence
of acidic aerosols and other pollutants, i.e.,
O3,PMio,SO2.
The Six-Cities Study in the United States
has examined the relationship between air
pollution and health for the past decade.
Although direct measurements of airborne
acidity were not performed during the
main study, subsequent measurements re-
vealed periods of high aerosol acidity in
several cities and at varying times. Using
these data and reanalyses of the original
symptoms prevalence data, it was observed
that acid concentrations were directly associ-
ated with an increased prevalence in
reported bronchitis in children.
53
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Along the eastern Canadian-US, trans-
boundary areas, aerosol acidity is dominated
by acidic sulphates (i.e., sulphuric acid
[HaSCU] and ammonium bisulphate
[NH4HSO4]). The level of acidic aerosols
during weather episodes also may have a
distinct diumal pattern, with peak acid
levels occurring in daylight hours, espe-
cially in the summer season. Current
measurement and population exposure
data for acidic aerosols are sparse. The
highest reported short-term (1- to 12-hour)
values ranged up to 30 to 50 M-g/m3 FfeSQi
(or equivalent HfcSOi). Such peaks are in-
frequent, but 24-hour values of 5 to 15
p.g/m may occur with regularity. The
highest peaks occur downwind of major
SOz emissions, from either large single
sources or urban source areas. However,
these data are insufficient to estimate with
much precision human exposure patterns
for acidic aerosols across the transbound-
ary area.
QUALITY ASSURANCE
Canada
In order to ensure credibility of data in
the Acid Rain Program, inter-laboratory
studies are routinely carried out. This ex-
ternal quality assurance program has ad-
dressed the laboratory measurement process
and audits the long-term performance of
laboratories. Three inter-laboratory perform-
ance evaluation studies (10 samples for about
22 constituents) have been presented annu-
ally, since 1982, in addition to one study on
vegetation annually (10 samples for about 25
constituents). The routine provision of these
studies is believed to have created an atmos-
phere conducive to improvements to the
measurement process.
r£
| 40 _
20 —
(•) Each value equals the percentage of
biased parameters plus percentage of
flagged results (Maximum score 200%).
I
.). |
Poor
Moderate
Satisfactory
\ \ \ I I I I
1983 1984 1985 1986 1987 1988 1989 1990 1991
LRTAP Studies No. 1 to 22 (1983 -1990)
Impact of external QA on the performance of
one laboratory.
Evidence from these studies during
1990 and 1991 indicates that improvements
in the measurement process continue to
take place. An example of how one labora-
tory's performance has improved due to
participation in a quality assurance pro-
gram is shown in Figure 13. The data base
management system that has archived
over 30 large inter-comparison studies is
viewed as a valuable resource for use by
data users. This information base in-
cludes inter-laboratory results from
over 100 Canadian and 25 American
laboratories.
United States
Quality assurance was an integral part
of the NAPAP process. Information on a
number of quality assurance activities can
be found in the NAPAP documents.
54
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In 1990 and 1991, EPA conducted per-
formance audits on 50 percent of the 3,700
air samplers being operated by 169 air pol-
lution control agencies in the United States
as part of the State and Local Air Monitor-
ing Network. In these audits, which began
in 1975, each agency received performance
evaluation samples that they introduced as
blind unknowns into their CO, NCh, SQz,
Oa, Pb, and PM-10 samplers. Similar audits
also were done on the large variety of sta-
tionary sources that emit toxic and acidic
pollutants. Other audits included special
studies measuring the deposition of toxic
compounds into the Great Lakes and on
several large-scale acid precipitation moni-
toring networks.
CONTROL TECHNOLOGIES
In Article VII of the Air Quality Agree-
ment, Canada and the United States have
agreed to "exchange, on a regular basis and
through the Air Quality Committee estab-
lished under Article VIE, information on.. .
technologies, measures and mechanisms for
controlling emissions." Annex 2 further
specifies that the two countries agree to co-
operate and exchange information regarding
their development and demonstration of
technologies and measures for controlling
emissions of air pollutants, in particular
acidic deposition precursors, subject to their
respective laws, regulations, and policies.
Canada
In general, control efforts in Canada
have been directed towards the non-fer-
rous smelters and fossil fuel burning
power plants which produced about 60
and 20 percent, respectively, of Canada's
SO2 emissions in 1985.
In conjunction with government, the
targeted smelters have researched, devel-
oped, and are implementing major techno-
logical improvements including increased
phyrrotite rejection, advanced milling and
beneficiation, zinc pressure leaching, and
advanced smelting processes. Sulphur
emissions are being effectively captured as
liquid SQz and acid; both are marketable
products. By 1994, these new facilities,
costing nearly $900 million, will enable the
smelters to meet their targets.
The federal and provincial govern-
ments, in cooperation with the electric
power utilities, continue to conduct re-
search and development on fuels, ad-
vanced combustion, and flue gas control
technologies. Areas of recent research and
development on SO2 control for power
plants include the following:
• Development of furnace sorbent in-
jection systems and tests in Ontario
and Saskatchewan.
« Trial burns of low sulphur fuels and
flue gas conditioning systems in
Ontario.
• Trial burns of Orimulsion (water-bi-
tumen blend) fuel in New Brunswick.
• Development and trials of a low
NOx/SOx (LNS) burner in Alberta.
• Development and testing of the
SONOx process in Ontario.
• Development and trials of the Un-
ion Carbide CANSOLVE process in
Alberta.
« Development and operation of an at-
mospheric fluidized bed combustion
demonstration unit to burn high sul-
The original
recommendation for
a multi-billion dollar
clean coal
demonstration
program came in
1986 from the U.S.
and Canadian
Special Envoys on
Acid Rain after
studying ways to
resolve concerns
between the two
nations over the
transboundary
problem of acid rain.
55
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phur coal, petroleum coke, oil shale,
wood waste, and other fuels at
Chatham, New Brunswick.
Government/industry research pro-
grams on SO2 and NOx emission control
are expected to continue in the coming
years. Canada's Green Plan contains a ma-
jor initiative on "Technology for Solutions"
to assist in these further research efforts.
United States
While the United States had a pollution
control technology program for many
years, the original recommendation for a
multi-billion dollar clean coal demonstra-
tion program came in 1986 from the U.S.
and Canadian Special Envoys on Acid
Rain after studying ways to resolve con-
cerns between the two nations over the
transboundary problem of acid rain. Con-
sensus was that demonstration of innova-
tive control technologies should lead to
some near-term reductions in sulphur di-
oxide and nitrogen oxides, and, sub-
sequently, in acid rain.
Begun by Congress in 1986 and ex-
panded by two Presidential administra-
tions, the Clean Coal Technology (CCT)
Program is expected to finance more than
$5 billion of projects when completed in
the 1990s. The resulting power generating
and pollution control technologies are
products of years of research and develop-
ment in numerous government and pri-
vate laboratories. Lead by the U.S.
Department of Energy, the CCT is a co-
funded effort by government and industry
to demonstrate the utility and merit of new
coal burning processes in a series of full-
scale commercial facilities. Canada was
represented on the Innovative Coal Tech-
nology Assessment Panel, set up to pro-
vide advice and recommendations on pro-
jects. The program will take the most
promising of the advanced coal-based
technologies and, over the next decade and
beyond, move them into the commercial
marketplace.
CCT represents a fundamental change
in coal-fired power plant technology. Pro-
jects in the CCT offer lower sulphur diox-
ide and/or nitrogen oxides emission levels
than does conventional pulverized coal
combustion. Some offer substantially
lower emissions than even scrubber-
equipped plants. In many cases, emission
reductions and cost improvements are
achieved concurrently as these technolo-
gies are expected to operate more effi-
ciently than conventional plants. Finally,
while conventional scrubbing produces
large amounts of solid waste which must
be disposed of, some clean coal technolo-
gies also are very low waste generators or
provide easily recycled waste.
The CCT is being implemented through
a total of five competitive solicitations,
four of which have been completed. Each
solicitation maintains a strong emphasis
on mitigation of the acid rain precursor
emissions of sulphur dioxide and nitrogen
oxides, consistent with the recommenda-
tions of the U.S. and Canadian Special En-
voys on Acid Rain. Objectives include
demonstrating the feasibility of future
commercial applications and significant re-
duction of sulphur dioxide and/or nitro-
gen oxides from existing facilities;
providing future energy needs in an envi-
ronmentally acceptable manner; and demon-
strating technologies capable of retrofitting,
repowering, or replacing existing facilities
while achieving all of the above. Projects
vary in design, in target percent emissions
56
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reduction, and in commercial application
and availability. Percent reduction, for ex-
ample, ranges from 70 to 99 percent for
sulphur dioxide and 50 to 95 percent for
nitrogen oxides.
There are currently 42 active projects in
the CCT Program. Three projects have
been completed. There are 19 projects in
the design phase or under construction
and 10 in operation. The remaining 10 pro-
jects are in negotiation. By the year 2000,
of the 33 projects selected under the first
three CCT solicitations, 30 will have com-
pleted operation and be commercially
available. Approximately six of the nine
projects selected should have completed
their operational phase and also be com-
mercially available. The schedules for
Round 4 projects are tentative and subject
to final negotiation. When the projects are
completed, the sponsors and participants
will be in a position to use the information
and experience gained during demonstra-
tions to promote and market the technolo-
gies in commercial applications.
Total project costs through the first four
solicitations under the program amount to
approximately $4.4 billion, which includes
a government share of $1.8 billion.
Canada and the United States hold an
annual meeting on control technologies
under a Memorandum of Understanding.
During this meeting, all CCT publications
(Program Update, Comprehensive Reports
to Congress, Topical reports, etc.) are
made available to the Canadian repre-
sentatives. Canadian agencies participat-
ing in the exchange include CANMET and
the Alberta Research Council.
MARKET-BASED MECHANISMS
In Annex 2 of the Air Quality Agreement,
Canada and the United States agreed to coop-
erate and exchange information regarding
their analysis of market-based mechanisms,
including emissions trading.
Each country is exploring the use of
market-based incentives for environ-
mental policy, because, in appropriate
applications, these tools offer the promise
of achieving environmental goals more ef-
fectively at less cost. In the United States,
market-based incentives are currently in
use in the acid rain control program (as
described above in this report) and in the
program to phase out chlorofluorocarbon
(CFC) production. Market incentives also
were used successfully to phase out
leaded gasoline.
Within the mandate of the Canadian
Council of Ministers of the Environment
(CCME) is the consideration of non-regu-
latory mechanisms for managing air
emissions in Canada such as the use of
emissions trading. To this end, two work-
ing groups were established under CCME,
one for NOx/VOC and one for SC>2. The
two groups developed in the fall of 1991 a
policy paper entitled "Emission Trading:
A Canadian Policy Framework." This pa-
per summarizes the concept of emission
trading and the results of a consultant's
study on some of the U.S. experience with
emission trading, but it mainly focuses on
policy, administrative, and program de-
sign issues. This preliminary work is being
followed up with a more detailed exami-
nation of the design of trading systems for
NOx/VOCs in the Lower Eraser Valley
57
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Region of British Columbia and for NOx in
the Ontario portion of the Windsor-Que-
bec corridor. Work is under way to
examine the feasibility and design of na-
tional or regional emission trading systems
as a means of managing the national SQz
emission cap. The work is expected to be
completed by the end of 1992.
Canada and the United States are hold-
ing a series of meetings to share analyses
of market-based incentives for environ-
mental protection. Following initial
consultations in Ottawa in December 1990,
EPA hosted a meeting on this topic in De-
cember 1991 in Washington, attended by
Environment Canada and representatives
of several agencies of each government.
The meeting discussed the experience
gained in the United States in implementa-
tion of the lead phase down and the acid
rain programs, as well as plans for emis-
sion trading in southern California to ad-
dress urban air quality. Canada indicated
its interest in using market incentives to
address regional acid rain and urban air
quality issues, the latter particularly in the
Vancouver and Windsor- Quebec areas.
The two countries will continue meeting
and sharing information on market-based
incentives on an ongoing basis. The Decem-
ber 1991 meeting identified as key areas for
future cooperation and information ex-
change acid rain, urban ozone, Great Lakes
water quality, and options for cost-effective
greenhouse gas emissions abatement. Since
each of these issues can involve emission
sources and/or pollution dispersion across a
shared border, the possibility of including
both U.S. and Canadian sources in a market-
based incentive program also will be
expanded.
58
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SECTION IV
Conclusion
This is the first progress report un-
der the United States-Canada Air
Quality Agreement. Since the sign-
ing of the Agreement in March
1991, the two countries have taken significant
steps towards fulfilling the letter and the
spirit of the Agreement. They have formed a
bilateral Air Quality Committee and two sub-
committees to assist in carrying out the terms
of the Agreement. They have initiated, contin-
ued, and expanded working relationships in a
variety of areas related to North American air
quality. Most importantly, there has been a
free exchange of people and information
across our borders. While such exchanges oc-
curred prior to the signing of the Air Quality
Agreement, the number of contacts and the
degree of cooperation and exchange of infor-
mation have increased significantly, to the
benefit of both countries.
Canada and the United States are making
considerable progress in implementing pro-
grams aimed at the reduction of sulphur
dioxide and nitrogen oxides. In Canada, the
Eastern Canada Acid Rain Control Program
is well on its way toward meeting its goals
in 1994. In the United States, there has been
considerable progress in promulgating the
regulations that will implement the acid rain
control provisions of the CAA. Both coun-
tries are sharing information with the other
on a variety of issues related to program im-
plementation, including the use of
market-based incentives to achieve more
cost-effective emission reductions.
Both countries are continuing a variety of
scientific and technical activities and are co-
ordinating/cooperating with one another in
a number of areas, including emission inven-
tories, atmospheric modeling, deposition
monitoring, effects research and monitoring,
human health, and control technologies.
The next progress report under the Air
Quality Agreement is due out in 1994. Over
the next two years, Canada and the United
States will continue to implement their re-
spective control programs and to share
information with one another on their re-
spective experiences as they approach
important emission reduction milestones.
Future research and monitoring efforts
related to acidic deposition include the
following:
m Providing up-to-date inventories of
total sulphur dioxide and nitrogen
oxides emissions.
• Measuring air quality and deposition
values and refining the predictive ca-
pabilities of atmospheric models.
m Recording the chemical and biological
improvements in surface waters and
responses to changing deposition.
• Determining the role of nitrogen
deposition in ecosystem processes
and the implications for control of
acidification of surface waters.
m Resolving the role of acidic deposi-
tion in the forest decline problem.
a Evaluating the human health effects of
acid aerosols and related pollutants.
Much of this work will be carried out
jointly or cooperatively by Canadian and
American scientists over the next several
years. Progress in these areas will be re-
ported in 1994.
59
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APPENDIX A
United States-Canada
Air Quality Committee
CANADIAN MEMBERS
Co-chair
Peter M. Higgins
Assistant Deputy Minister
Conservation and Protection
Environment Canada
H.A. (Tony) Clarke
Director General
Environmental Protection
Environment Canada
Phil Merilees
Director General
Atmospheric Research Directorate
Environment Canada
John Lowe
Director, International Trade
and U.S. Relations
Energy Policy Branch
Energy, Mines and Resources
David McLellan
Deputy Director
U.S. Transboundary Division
External Affairs and International Trade
Canada
Larry Lechner
Director, Air and Land Protection Branch
Saskatchewan Environment and
Public Safety
EdPiche
Director, Air Resources Branch
Ontario Ministry of the Environment
Laval Lapointe
Acid Rain Coordinator
Ministrere de 1'Environment
Gouvernement du Quebec
Creighton Brisco
Manager, Air Quality Branch
Nova Scotia Department of the
Environment
U.S. MEMBERS
Co-chair
Richard J. Smith
Principal Deputy Assistant Secretary
Bureau of Oceans and International
Environmental and Scientific Affairs
Department of State
Robert H. Pines
Deputy Assistant Secretary for
Canadian Affairs
Department of State
Eileen Claussen
Director, Office of Atmospheric and
Indoor Air Programs
Environmental Protection Agency
David Kee
Director, Air and Radiation Division
Region 5
Environmental Protection Agency
Howard Gruenspecht
Associate Deputy Undersecretary for
Program Analysis
Department of Energy
61
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Richard Williamson
Associate Deputy Assistant
Secretary for International Affairs
Department of Energy
Edward Cassidy
Deputy Chief of Staff and Deputy
Assistant Secretary for Policy
Department of Interior
Bruce Hicks
Director, Air Resources Laboratory
Department of Commerce/NOAA
Scott Farrow
Associate Director for Pollution Control
and Prevention
Council of Environmental Quality
SUBCOMMITTEE ON PROGRAM
MONITORING
AND REPORTING
Co-chairs:
Wayne Draper
Associate Director (Air)
Industrial Programs Branch
Environment Canada
Brian McLean
Director, Acid Rain Division
Office of Atmospheric and Indoor Air
Programs
Office of Air and Radiation
Environmental Protection Agency
SUBCOMMITTEE ON SCIENTIFIC
COOPERATION
Co-chairs:
Tom Brydges
Director, Environmental Integration
Services Branch
Atmospheric Environment Service
Environment Canada
Jack Puzak
Deputy Director, Office of Modeling,
Monitoring Systems, and Quality
Assurance
Office of Research and Development
Environmental Protection Agency
62
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TERMS OF REFERENCE
U.S.-Canada Air Quality Committee
1. Review progress made in the imple-
mentation of the Agreement, includ-
ing its general and specific objectives.
2. Prepare and submit to the Parties a
progress report within a year after
entry into force of the Agreement and
at least every two years thereafter.
3. Refer each progress report to the In-
ternational Joint Commission for ac-
tion in accordance with Article IX of
the Agreement.
4. Release each progress report to the
public after its submission to the Parties.
5. Establish reporting subcommittees
as required to fulfill the above
responsibilities.
6. Meet at least once a year and addi-
tionally at the request of either Party.
7. Not release, without the consent of the
owner, any information identified to it
as proprietary information under the
laws of the place where such informa-
tion has been acquired.
63
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TERMS OF REFERENCE
Subcommittee on Program
Monitoring and Reporting
1. Coordinate activities as outlined in
paragraph 2 of Annex 2 to the Agree-
ment for the purpose of determining
and reporting on air emission levels,
historical trends, and projections.
2. Cooperate and exchange information
on development and demonstration
of technologies and measures for con-
trolling emissions of air pollutants, in
particular, acidic deposition precur-
sors, subject to respective laws, regu-
lations, and policies, as set forth in
subparagraph 3(d) of Annex 2 to the
Agreement.
3. Cooperate and exchange information
on their analysis of market-based
mechanisms, including emission trad-
ing, as set forth in paragraph 3(e) of
Annex 2 to the Agreement.
4. Cooperate and exchange information
with respect to economic research that
the Parties may agree upon for pur-
poses of supporting the general and
specific objectives of the Agreement, as
set forth in paragraph 3(f) of Annex 2
to the Agreement.
5. Develop and revise, as necessary, rec-
ommendations to the Air Quality
Committee on operational guidelines
for implementation of Article V(2),
and cooperate and exchange informa-
tion regarding implementation of sec-
tions 3 and 4 of Annex 1 to the
Agreement.
6. Assist the Air Quality Committee in
reviewing progress made in the im-
plementation of the Agreement, in-
cluding its general and specific
objectives, as required under Article
VIII of the Agreement, with respect to
areas within its purview.
7. Prepare necessary input on issue areas
within its purview for the reports of
the Air Quality Committee required
under Article VIII of the Agreement.
8. Support the Air Quality Committee
in its preparation of the report re-
quired under Article VIII.
9. Establish ad hoc bilateral working
groups as may be required to fulfill
the above responsibilities.
-------
TERMS OF REFERENCE
Subcommittee on
Scientific Cooperation
1. Coordinate air pollutant monitoring
activities as set forth in paragraph 1
of Annex 2 to the Agreement for the
purpose of determining and report-
ing on air pollutant concentrations
and deposition.
2. Cooperate and exchange information
on their monitoring of the effects of
changes in air pollutant concentration
and deposition, with respect to
changes in various effects categories,
e.g., aquatic ecosystems, visibility, and
forests, as set forth in subparagraph
3(a) of Annex 2 to the Agreement.
3. Cooperate and exchange information
on their determination of any effects
of atmospheric pollution on human
health and ecosystems, as set forth in
subparagraph 3(b) of Annex 2 to the
Agreement.
4. Cooperate and exchange information
on the development and refinement
of atmospheric models for purposes
of determining source receptor rela-
tionships and transboundary trans-
port and deposition of air pollutants,
as set forth in subparagraph 3(c) of
Annex 2 to the Agreement.
5. Consult on approaches to, and share in-
formation and results of research on,
methods to mitigate the impacts of
acidic deposition, including the envi-
ronmental effects and economic aspects
of such methods, as set forth in para-
graph 4 of Annex 2 to the Agreement.
6. Cooperate and exchange information
with respect to any other scientific or
technical activities that the Parties ask it
to undertake to support the general and
specific objectives of the Agreement.
7. Prepare the necessary scientific input
for the reports of the Air Quality
Committee as required under Article
VIII of the Agreement.
8. Establish ad hoc bilateral working
groups as may be required to fulfill
the above responsibilities.
65
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AP P END IX B
Agreement between the
Government of the United
States of America and the
Government of Canada on
Air Quality
T
he Government of the United
States of America and the Gov-
ernment of Canada, hereinafter
referred to as "the Parties,"
Convinced that transboundary air pollu-
tion can cause significant harm to natural
resources of vital environmental, cultural
and economic importance, and to human
health in both countries;
Desiring that emissions of air pollutants
from sources within their countries not re-
sult in significant transboundary air
pollution;
Convinced that transboundary air pollu-
tion can effectively be reduced through
cooperative or coordinated action provid-
ing for controlling emissions of air
pollutants in both countries;
Recalling the efforts they have made to
control air pollution and the improved air
quality that has resulted from such efforts
in both countries;
Intending to address air-related issues
of a global nature, such as climate change
and stratospheric ozone depletion, in other
fora;
Reaffirming Principle 21 of the Stock-
holm Declaration, which provides that
"States have, in accordance with the Char-
ter of the United Nations and the
principles of international law, the sover-
eign right to exploit their own resources
pursuant to their own environmental poli-
cies, and the responsibility to ensure that
activities within their jurisdiction or con-
trol do not cause damage to the
environment of other States or of areas be-
yond the limits of national jurisdiction";
Noting their tradition of environmental
cooperation as reflected in the Boundary
Waters Treaty of 1909, the Trail Smelter
Arbitration of 1941, the Great Lakes Water
Quality Agreement of 1978, as amended,
the Memorandum of Intent Concerning
Transboundary Air Pollution of 1980, the
1986 Joint Report of the Special Envoys on
Acid Rain, as well as the ECE Convention
on Long-Range Transboundary Air Pollu-
tion of 1979;
Convinced that a healthy environment
is essential to assure the well-being of pres-
ent and future generations in the United
States and Canada, as well as of the
global community;
67
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Have agreed as follows:
ARTICLE I
Definitions
For the purposes of this Agreement:
1. "Air pollution" means the introduc-
tion by man, directly or indirectly, of
substances into the air resulting in
deleterious effects of such a nature as
to endanger human health, harm liv-
ing resources and ecosystems and
material property and impair or in-
terfere with amenities and other le-
gitimate uses of the environment, and
"air pollutants" shall be construed ac-
cordingly;
2. "Transboundary air pollution" means
air pollution whose physical origin is
situated wholly or in part within the
area under the jurisdiction of one
Party and which has adverse effects,
other than effects of a global nature,
in the area under the jurisdiction of
the other Party;
3. "Boundary Waters Treaty" means the
Treaty Relating to Boundary Waters
and Questions Arising along the
Boundary between the United States
and Canada, signed at Washington
on January 11,1909;
4. "International Joint Commission"
means the International Joint Com-
mission established by the Boundary
Waters Treaty.
ARTICLE II
Purpose
The purpose of the Parties is to estab-
lish, by this Agreement, a practical and
effective instrument to address shared con-
cerns regarding transboundary air pollution.
ARTICLE III
General Air Quality Objective
1. The general objective of the Parties is
to control transboundary air pollu-
tion between the two countries.
2. To this end, the Parties shall:
(a) in accordance with Article IV, estab-
lish specific objectives for emissions
limitations or reductions of air pol-
lutants and adopt the necessary
programs and other measures to
implement such specific objectives;
(b) in accordance with Article V, un-
dertake environmental impact assess-
ment, prior notification, and, as
appropriate, mitigation measures;
(c) carry out coordinated or coopera-
tive scientific and technical
activities, and economic research, in
accordance with Article VI, and ex-
change information, in accordance
with Article VII;
(d) establish institutional arrange-
ments, in accordance with Articles
VIII and IX; and
(e) review and assess progress, con-
sult, address issues of concern,
and settle disputes, in accordance
with Articles X, XI, XII, and XIII.
ARTICLE IV
Specific Air Quality Objectives
1. Each Party shall establish specific
objectives, which it undertakes to
achieve, for emissions limitations or
reductions of such air pollutants as
the Parties agree to address. Such
specific objectives will be set forth in
annexes to this Agreement.
68
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2. Each Party's specific objectives for
emissions limitations or reductions of
sulphur dioxide and nitrogen oxides,
which will reduce transboundary
flows of these acidic deposition pre-
cursors, are set forth in Annex 1. Spe-
cific objectives for such other air
pollutants as the Parties agree to ad-
dress should take into account, as ap-
propriate, the activities undertaken
pursuant to Article VI.
3. Each Party shall adopt the programs
and other measures necessary to im-
plement its specific objectives set
forth in any annexes.
4. If either Party has concerns about the
programs or other measures of the
other Party referred to in paragraph
3, it may request consultations in ac-
cordance with Article XI.
ARTICLE V
Assessment, Notification, and
Mitigation
1. Each Party shall, as appropriate and
as required by its laws, regulations
and policies, assess those proposed
actions, activities and projects within
the area under its jurisdiction that, if
carried out, would be likely to cause
significant transboundary air pollu-
tion, including consideration of ap-
propriate mitigation measures.
2. Each Party shall notify the other
Party concerning a proposed action,
activity or project subject to assess-
ment under paragraph 1 as early as
practicable in advance of a decision
concerning such action, activity or
project and shall consult with the
other Party at its request in accord-
ance with Article XI.
3. In addition, each Party shall, at the
request of the other Party, consult in
accordance with Article XI concern-
ing any continuing actions, activities
or projects that may be causing sig-
nificant transboundary air pollu-
tion, as well as concerning changes to
its laws, regulations or policies that,
if carried out, would be likely to
significantly affect transboundary air
pollution.
4. Consultation pursuant to paragraphs
2 and 3 concerning actions, activities
or projects that would be likely to
cause or may be causing significant
transboundary air pollution shall in-
clude consideration of appropriate
mitigation measures.
5. Each Party shall, as appropriate, take
measures to avoid or mitigate the po-
tential risk posed by actions, activi-
ties or projects that would be likely to
cause or may be causing significant
transboundary air pollution.
6. If either Party becomes aware of an
air pollution problem that is of joint
concern and requires an immediate
response, it shall notify and consult
the other Party forthwith.
ARTICLE VI
Scientific and Technical Activities
and Economic Research
1. The Parties shall carry out scientific
and technical activities, and economic
research, as set forth in Annex 2, in or-
der to improve their understanding of
transboundary air pollution concerns
69
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and to increase their capability to
control such pollution.
2. In implementing this Article, the Par-
ties may seek the advice of the Inter-
national Joint Commission regarding
the conduct of monitoring activities.
ARTICLE VII
Exchange of Information
1. The Parties agree to exchange, on a
regular basis and through the Air
Quality Committee established under
Article VIII, information on:
(a) monitoring;
(b) emissions;
(c) technologies, measures and mecha-
nisms for controlling emissions;
(d) atmospheric processes; and
(e) effects of air pollutants,
as provided in Annex 2.
2. Notwithstanding any other provi-
sions of this Agreement, the Air
Quality Committee and the Interna-
tional Joint Commission shall not re-
lease, without the consent of the
owner, any information identified to
them as proprietary information un-
der the laws of the place where such
information has been acquired.
ARTICLE VIII
The Air Quality Committee
1. The Parties agree to establish and
maintain a bilateral Air Quality Com-
mittee to assist in the implementation
of this Agreement. The Committee
shall be composed of an equal num-
ber of members representing each
Party. It may be supported by sub-
committees, as appropriate.
2. The Committee's responsibilities shall
include:
(a) reviewing progress made in the
implementation of this Agree-
ment, including its general and
specific objectives;
(b) preparing and submitting to the
Parties a progress report within a
year after entry into force of this
Agreement and at least every two
years thereafter;
(c) referring each progress report to
the International Joint Commis-
sion for action in accordance with
Article IX of this agreement; and
(d) releasing each progress report to
the public after its submission to
the Parties.
3. The Committee shall meet at least
once a year and additionally at the
request of either Party.
ARTICLE IX
Responsibilities of the International
Joint Commission
1. The International Joint Commission is
hereby given, by a Reference pursuant
to Article IX of the Boundary Waters
Treaty, the following responsibilities for
the sole purpose of assisting the Parties in
the implementation of this Agreement:
(a) to invite comments, including
through public hearings as appro-
priate, on each progress report
prepared by the Air Quality Com-
mittee pursuant to Article VIII;
(b) to submit to the Parties a synthesis
of the views presented pursuant to
sub-paragraph (a), as well as the re-
cord of such views if either Party so
requests; and
70
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(c) to release the synthesis of views
to the public after its submission
to the Parties.
2. In addition, the parties shall consider
such other joint references to the In-
ternational Joint Commission as may
be appropriate for the effective im-
plementation of this Agreement.
ARTICLE X
Review and Assessment
1. Following the receipt of each progress
report submitted to them by the Air
Quality Committee in accordance
with Article VIII and the views pre-
sented to the International Joint
Commission on that report in accord-
ance with Article IX, the Parties shall
consult on the contents of the pro-
gress report, including any recom-
mendations therein.
2. The Parties shall conduct a compre-
hensive review and assessment of
this Agreement, and its implementa-
tion, during the fifth year after its en-
try into force and every five years
thereafter, unless otherwise agreed.
3. Following the consultations referred
to in paragraph 1, as well as the re-
view and assessment referred to in
paragraph 2, the Parties shall con-
sider such action as may be appropri-
ate, including:
(a) the modification of this Agreement;
(b) the modification of existing poli-
cies, programs or measures.
ARTICLE XI
Consultations
The Parties shall consult, at the request
of either Party, on any matter within the
scope of this Agreement. Such consultations
shall commence as soon as practicable, but
in any event not later than 30 days from
the date of receipt of the request for con-
sultations, unless otherwise agreed by the
Parties.
ARTICLE XII
Referrals
With respect to cases other than those
subject to Article XIII, if, after consultations
in accordance with Article XI, an issue re-
mains concerning a proposed or continuing
action, activity, or project that is causing or
would be likely to cause significant trans-
boundary air pollution, the Parties shall
refer the matter to an appropriate third
party in accordance with agreed terms of
reference.
ARTICLE XIII
Settlement of Disputes
1. If, after consultations in accordance
with Article XI, a dispute remains be-
tween the Parties over the interpreta-
tion or the implementation of this
Agreement, they shall seek to resolve
such dispute by negotiations be-
tween them. Such negotiations shall
commence as soon as practicable, but
in any event not later than 90 days
from the date of receipt of the re-
quest for negotiation, unless other-
wise agreed by the Parties.
71
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2. If a dispute is not resolved through ne-
gotiation, the Parties shall consider
whether to submit that dispute to the
International Joint Commission in ac-
cordance with either Article IX or Arti-
cle X of the Boundary Waters Treaty. If,
after such consideration, the Parties do
not elect either of those options, they
shall, at the request of either Party, sub-
mit the dispute to another agreed form
of dispute resolution.
ARTICLE XIV
Implementation
1. The obligations undertaken under
this Agreement shall be subject to the
availability of appropriated funds in
accordance with the respective con-
stitutional procedures of the Parties.
2. The Parties shall seek:
(a) the appropriation of funds required
to implement this Agreement;
(b) the enactment of any additional
legislation that may be necessary
to implement this Agreement;
(c) the cooperation of State and Pro-
vincial Governments as necessary
to implement this Agreement.
3. In implementing this Agreement, the
Parties shall, as appropriate, consult
with State or Provincial Governments,
interested organizations, and the public.
ARTICLE XV
Existing Rights and Obligations
Nothing in this Agreement shall be
deemed to diminish the rights and obliga-
tions of the Parties in other international
agreements between them, including those
contained in the Boundary Waters Treaty
and the Great Lakes Water Quality Agree-
ment of 1978, as amended.
ARTICLE XVI
Entry into Force, Amendment,
Termination
1. This Agreement, including Annexes 1
and 2, shall enter into force upon sig-
nature by the Parties.
2. This Agreement may be amended at
any time by agreement of the Parties
in writing.
3. Either Party may terminate this
agreement upon one year's written
notice to the other Party, in which
case any annexes will also terminate.
4. Annexes constitute an integral part of
this Agreement, except that, if an an-
nex so provides, either Party may ter-
minate such annex in accordance
with the terms of that annex.
72
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IN WITNESS WHEREOF, the under-
signed have signed this Agreement.
DONE in duplicate, at Ottawa, this
13th day of March, 1991, in the English
and French languages, each version
being equally authentic.
v/
FOR THE GOVERNMENT OF THE
UNITED STATES OF AMERICA
POUR LE GOUVERNEMENT DBS
ESTAS-UNIS D'AMERIQUE
EN FOIDE QUOI, les soussignes ont
signe le present Accord.
FATT en deux exemplaires a OTTAWA,
ce 13e jour de mars, 1991, en langues
anglaise et francaise, les deux ver-
sions faisant egalement foi.
FOR THE GOVERNMENT OF
CANADA
POUR LE GOUVERNEMENT
DU CANADA
73
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ANNEX 1
Specific Objectives Concerning
Sulphur Dioxide and Nitrogen
Oxides
1. Sulphur Dioxide
A. For the United States:1
1. Reduction of annual sulphur dioxide
emissions by approximately 10 million
tons2 from 1980 levels in accordance
with Tifle IV of the dean Air Act3 i.e.,
reduction of annual sulphur dioxide
emissions to approximately 10 mil-
lion tons below 1980 levels by 2000
(with the exception of sources repow-
ering with qualifying clean coal tech-
nology in accordance with section 409
of the Clean Air Act, and sources re-
ceiving bonus allowances in accord-
ance with sections 405(a)(2) and (3) of
the Clean Air Act).
2. Achievement of a permanent national
emission cap of 8.95 million tons of
sulphur dioxide per year for electric
utilities by 2010, to the extent re-
quired by Title IV of the Clean Air
Act.
3. Promulgation of new or revised
standards or such other action under
the Clean Air Act as the Administrator
of the U.S. Environmental Protection
Agency (EPA) deems appropriate, to
the extent required by section 406 of
the Clean Air Act Amendments of
1990 (P. L. 101-549), aimed at limiting
sulphur dioxide emissions from in-
dustrial sources in the event that the
Administrator of EPA determines
that annual sulphur dioxide emis-
sions from industrial sources may
reasonably be expected to exceed 5.6
million tons.
B. For Canada:
1. Reduction of sulphur dioxide emis-
sions in the seven easternmost Prov-
inces to 23 million tonnes per year by
1994 and the achievement of a cap on
sulphur dioxide emissions in the seven
easternmost Provinces at 2.3 million
tonnes per year from 1995 through De-
cember 31,1999.
2. Achievement of a permanent na-
tional emissions cap of 3.2 million
tonnes per year by 2000.
2. Nitrogen Oxides
A. For the United States1:
With a view to a reduction of total
annual emissions of nitrogen oxides
by approximately 2 million tons from
1980 emission levels by 2000:
1. Stationary Sources
Implementation of the following ni-
trogen oxides control program for
electric utility boilers to the extent re-
quired by Title IV of the Clean Air Act:
(a) By January 1, 1995, tangentially
fired boilers must meet an allow-
able emission rate of 0.45 Ib/mmBtu,
and dry bottom wall-fired boilers
must meet an allowable emission
rate of 050 Ib/mmBtu (unless the
Administrator of EPA determines
that these rates cannot be achieved
using low NOx burner technology).
1 - Applies only to reductions in emissions in the 48 contiguous states and the District of Columbia.
2 - 1 ton = 0.91 tonnes (metric tons).
3 - All references to the Clean Air Act refer to the Act as amended November 15,1990.
74
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(b) By January 1,1997, EPA must set
allowable emission limitations for:
• wet bottom wall-fired boilers;
• cyclones;
• units applying cell burner tech-
nology; and
• all other types of utility boilers.
2. Mobile Sources
Implementation of the following mo-
bile source nitrogen oxides control
program to the extent required by Ti-
tle II of the Clean Air Act:
(a) Light Duty Trucks (LOT) (up to
6,000 Ibs gross vehicle weight rat-
ing (GVWR)) and Light Duty
Vehicles (LDV)—standards for
model years after 1993:
LDTs (0 to
3,750 Ibs
Loaded
Vehicle
Weight
(LVW)) and
LDVs
Diesel LDTs
(0 to 3,750
Ibs LVW)
and LDVs
(before 2004)
LDTs (3,751
to 5,750 Ibs
LVW)
5 yrs/50,000
miles (useful
life)
0.4 grams per
mile (gpm)
1.0 gpm
0.7 gpm4
10 yrs/100,000
miles
0.6 gpm
1.25 gpm
0.97 gpm
In model year 1994, 40 percent of each manufac-
turer's sales volume must meet the above
standards. In 1995, the percentage shall increase to
80 percent and, after 1995, to 100 percent.
(b) Light Duty Trucks more than
6,000 Ibs GVWR (after model year
1995):
LDTs (3,751
to 5,750 Ibs
Test Weight
(TW))
LDTs (over
5,750 Ibs TW)
Gasoline
5yrs/50,000
miles
0.7 gpm
1.1 gpm
Gasoline and
Diesel
llyrs/
120,000 miles
0.98 gpm
1.53 gpm
In model year 1996,50 percent of each manufac-
turer's sales volume must meet the above
standards. Thereafter, 100 percent of each
manufacturer's sales volume must meet the
standard,
(c) Heavy Duty Trucks (HDT) of
more than 8,500 Ibs GVWR (after
model year 1990):
HDT (effective
model year 1991s)
HDT (model year
1998 and later)
Gasoline and Diesel
Engines
5.0 grams per brake
horsepower-hour5
(gbhp-hr)
4.0 gbhp-hr
Useful life5:
Gasoline Engines
Diesel Engines
Light heavy-duty
Medium heavy-duty
Heavy heavy-duty
8 yrs/1 10,000 miles
8 yrs/ 11 0,000 miles
8 yrs/185,000 miles
8 yrs/290,000 miles
4 - This standard does not apply to diesd-fuded LDTs (3,751 to 5,750 Ibs LVW).
5 - As set forth in EPA regulations in effect as of the entry into force of this Agreement.
75
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B. For Canada:
1. Stationary Sources
(a) As an interim requirement, reduc-
tion, by 2000, of annual national
emissions of nitrogen oxides from
stationary sources by 100,000
tonnes below the year 2000 fore-
cast level of 970,000 tonnes.
(b) By January 1, 1995, development
of further annual national emis-
sion reduction requirements from
stationary sources to be achieved
by 2000 and/or 2005.
2. Mobile Sources
(a) Implementation of a more stringent
mobile source nitrogen oxides con-
trol program for gasoline-powered
vehicles with standards no less
stringent than the following:
Light Duty Vehicles (up to 6,000
Ibs GVWR) (By model year 1996
for passenger cars; by model year
1996 for light duty trucks6):
Cars and Light Duty
Trucks (0 to 3,750 Ibs
LVW)
Light Duty Trucks
(3,751 to 5,750 Ibs
LVW)
5 yrs/80,000
kilometers (useful
life)
0.4 gpm
0.7 gpm
Medium Duty Vehicles (6,001 to
8,500 Ibs GVWR) (By model year
19976):
0 to 3,750 Ibs LVW
3,751 to 5,750 Ibs
LVW
Over 5,750 Ibs LVW
5yrs/80,000
kilometers (useful
life)
0.4 gpm
0.7 gpm
1.1 gpm
Heavy Duty Vehicles (over 8,500
Ibs GVWR) (By model year 19986):
Over 8,500 Ibs
GVWR
8yrs/110,000
kilometers (useful
life)
4.0 gbhp-hr
(b) Implementation of a more stringent
mobile source nitrogen oxides con-
trol program for diesel-powered
vehicles and engines with stand-
ards, to the extent possible, no less
stringent than the standards for the
respective duty classes of gasoline-
powered vehicles and engines.
3. Compliance Monitoring
A. Utility Units
1. For the United States:
Requirement that, by January 1, 1995,
each new electric utility unit and each
electric utility unit greater than 25
MWe existing on the date of enactment
of the Clean Air Act amendments of
6 - The Government of Canada will propose this effective date; the final effective date is subject to the
procedures and outcome of the regulation development process.
76
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1990 (November 15, 1990) emitting
sulphur dioxide or nitrogen oxides
install and operate continuous emis-
sion monitoring systems or alterna-
tive systems approved by the
Administrator of EPA, to the extent re-
quired by section 412 of the dean Air
Act.
Z For Canada:
Requirement that, by January 1,1995,
Canada estimate sulphur dioxide and
nitrogen oxides emissions from each
new electric utility unit and each exist-
ing electric utility unit greater than 25
MWe using a method of comparable
effectiveness to continuous emission
monitoring, as well as investigate the
feasibility of using and implement,
where appropriate, continuous emis-
sion monitoring systems.
3. For Both Parties:
The Parties shall consult, as appropri-
ate, concerning the implementation of
the above.
B. Other Major Stationary Sources
Requirement that the Parties work to-
wards utilizing comparably effective
methods of emission estimation for
sulphur dioxide and nitrogen oxides
emissions from all major industrial
boilers and process sources, includ-
ing smelters.
4. Prevention of Air Quality
Deterioration and Visibility
Protection
Recognizing the importance of preventing
significant air quality deterioration and pro-
tecting visibility, particularly for international
parks, national, state, and provincial parks,
and designated wilderness areas:
A. For the United States:
Requirement that the United States
maintain means for preventing sig-
nificant air quality deterioration and
protecting visibility, to the extent re-
quired by Part C of Title I of the
Clean Air Act, with respect to sources
that could cause significant trans-
boundary air pollution.
B. For Canada:
Requirement that Canada, by January
1,1995, develop and implement means
affording levels of prevention of sig-
nificant air quality deterioration and
protection of visibility comparable to
those in paragraph A above, with re-
spect to sources that could cause sig-
nificant transboundary air pollution.
C For Both Parties:
The Parties shall consult, as appropri-
ate, concerning the implementation
of the above.
ANNEX 2
Scientific and Technical Activities
and Economic Research
For the purpose of determining and report-
ing on air pollutant concentrations and
deposition, the Parties agree to coordinate
their air pollutant monitoring activities through:
(a) coordination of existing networks;
(b) additions to monitoring tasks of
existing networks of those air pol-
lutants that the Parties agree
should be monitored for the pur-
poses of this Agreement;
77
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(c) addition of stations or networks
where no existing monitoring fa-
cility can perform a necessary
function for purposes of this
Agreement;
(d) the use of compatible data manage-
ment procedures, formats, and
methods; and
(e) the exchange of monitoring data.
2. For the purpose of determining and
reporting air emissions levels, histori-
cal trends, and projections with re-
spect to the achievement of the
general and specific objectives set
forth in this Agreement, the Parties
agree to coordinate their activities
through:
(a) identification of such air emis-
sions information that the Parties
agree should be exchanged for the
purposes of this Agreement;
(b) the use of measurement and esti-
mation procedures of comparable
effectiveness;
(c) the use of compatible data man-
agement procedures, formats, and
methods; and
(d) the exchange of air emission infor-
mation.
3. The Parties agree to cooperate and
exchange information with respect to:
(a) their monitoring of the effects of
changes in air pollutant concen-
trations and deposition with
respect to changes in various ef-
fects categories, e.g., aquatic
ecosystems, visibility, and forests;
(b) their determination of any effects
of atmospheric pollution on hu-
man health and ecosystems, e.g.,
research on health effects of acid
aerosols, research on the long-
term effects of low concentrations of
air pollutants on ecosystems, possi-
bly in a critical loads framework;
(c) their development and refine-
ment of atmospheric models for
purposes of determining source
receptor relationships and trans-
boundary transport and deposition
of air pollutants;
(d) their development and demon-
stration of technologies and
measures for controlling emis-
sions of air pollutants, in particular
acidic deposition precursors, subject
to their respective laws, regulations
and policies;
(e) their analysis of market-based
mechanisms, including emission
trading; and
(f) any other scientific and technical
activities or economic research
that the Parties may agree upon
for purposes of supporting the
general and specific objectives of
this Agreement.
4. The Parties further agree to consult on
approaches to, and share information
and results of research on, methods to
mitigate the impacts of acidic deposi-
tion, including the environmental ef-
fects and economic aspects of such
methods.
78
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Article IX of the United States-Canada Air Quality Agreement assigns the Interna-
tional Joint Commission the responsibility of soliciting comments on this Progress
Report. You may send written comments to either of the following:
IN THE UNITED STATES
Secretary, U.S. Section
International Joint Commission
1250 23rd Street, NW
Suite 100
Washington, DC 20440
IN CANADA
Secretary, Canadian Section
International Joint Commission
100 Metcalfe Street
18th Floor
Ottawa, Ontario K1P5M1
If you are interested in obtaining information on the scientific and technical issues
of acid deposition, contact:
IN THE UNITED STATES
National Acid Precipitation
Assessment Program
722 Jackson Place, NW
Washington, DC 20503
IN CANADA
Environmental Integration
Services Branch
Environment Canada
4905 Dufferin Street
Downsview, Ontario M3H5T4
If you are interested in obtaining information on the acid deposition control
programs, contact:
IN THE UNITED STATES
Acid Rain Division
U.S. Environmental Protection Agency
Mail Code: 6204J
401 M Street, SW
Washington, DC 20460
IN CANADA
Acid Rain Program
Industrial Programs Branch
Environment Canada
351 St. Joseph Boulevard
Place Vincent Massey - 13th Floor
Hull, Quebec K1AOH3~
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