United States - Canada
Air Quality Agreement
PROGRESS REPORT
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United States - Canada
Air Quality Agreement
1994 PROGRESS REPORT
A Report By The Air Quality Committee
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Your Comments on this Report
Would be Appreciated
Article IX of the Canada-United States Air
Quality Agreement assigns the International
Joint Commission the responsibility of inviting
comments on this report. The Commission
will prepare a synthesis of the comments
received for the Governments of the United
States and Canada and for public release.
You may send written comments to either
of the following addresses:
Secretary, Canadian Section
International Joint Commission
100 Metcalfe St.
Ottawa, Ontario K1P 5M1
Secretary, United States Section
International Joint Commission
1250 23rd Street, NW, Suite 100
Washington, DC 20440
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CONTENTS
EXECUTIVE SUMMARY 1
SECTION I
Introduction 5
History of the Agreement 5
Public Comment on the 1992 Progress Report 5
Air Quality Committee: Current Activities 6
SECTION II
Progress: Specific Programs and Objectives 7
Overview 7
Implementation of Control Programs 7
Prevention of Significant Deterioration
and Visibility Protection 14
New Issues Under the Control Programs 15
Progress Under Article V of the Air Quality Agreement 16
SECTION III
Progress: Scientific and Technical
Activities and Economic Research 19
Emission Inventories 19
Sulphur Dioxide, Nitrogen Oxides, and VOC Emissions
in Canada and the United States from 1980 to 2010 19
Atmospheric Modelling 23
Monitoring Activities 24
Effects Research and Monitoring 27
Quality Assurance 42
Control Technologies 43
Market-Based Mechanisms 45
Assessment of the Costs, Benefits,
and Effectiveness of Clean Air Controls 46
SECTION IV
Areas of Future Cooperation — Ground-Level Ozone 47
Ongoing Cooperation 47
Existing Ground-Level Ozone Programs 47
Conclusion and Next Steps 48
Appendix A
United States - Canada Air Quality Committee 51
Appendix B
Agreement Between the Government of the United States
of America and the Government of Canada 55
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LIST OF FIGURES
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Canada's S02 Compliance Strategies 9
U.S. SO2 Compliance Strategies Reported for Phase I 12
SO, Emission Estimates 21
NOx Emission Estimates 22
VOC Emission Estimates 22
Median 1991 SO2 Air Concentrations at CAPMoN
and NDDN Sites
.25
1988 Wet S04 Deposition—Sea Salt Corrected (kg/ha/yr) 28
1989 Wet SO4 Deposition—Sea Salt Corrected (kg/ha/yr) 28
1990 Wet S04 Deposition—Sea Salt Corrected (kg/ha/yr) 28
1991 Wet S04 Deposition—Sea Salt Corrected (kg/ha/yr) 28
1988 Wet N03 Deposition (kg/ha/yr) 29
1989 Wet NO3 Deposition (kg/ha/yr) 29
1990 Wet N03 Deposition (kg/ha/yr) 29
1991 Wet N03 Deposition (kg/ha/yr) 29
Precipitation Weighted Mean SO| Concentration,
Sea Salt Corrected (mg/l)
.30
Precipitation Weighted Mean NOi Concentration (mg/l) 31
Normalized Annual SO2 Emissions and Sulphate
Wet Deposition, Sea Salt Corrected, Over Eastern North America
Normalized Annual NOx Emissions and Nitrate
Wet Deposition Over Eastern North America
.32
.33
Modelled Improvement in Visibility for the Average Day,
1985-2010 (Improvement is expressed in terms of deciviews)
.40
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LIST OF TABLES
Table 1
Table 2
Table 3
Table 4
Table 5
Canada-United States SO, Emission Reduction Goals
Total SO2 Emissions By Provinces in Eastern Canada (kilotonnes) 8
New Canadian Source Performance Standards for NOx Emissions
from New Power Boilers
.10
Emission Estimates for Canada and the United States, 1992 20
Comparison of Canadian CAPMoN and U.S. NDDN
Filterpack Measurement of Acidifying Air Pollutants
.42
Table 6
Classification of U.S. Ozone Nonattainment Areas 48
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Executive Summary
The Canada-United States Air Quality Agreement,
now three years old, has successfully drawn
together work in Canada and the United States
on air quality issues.
This second Progress Report builds on the 1992
Canada-U.S. Progress Report. It reviews acid
rain control programs, monitoring, and other
scientific activities currently being undertaken
by each country individually and together.
The report also covers issues not specifically
addressed in the original agreement, including
ground-level ozone (smog).
Programs to Reduce
Acid Rain Emissions
Acid rain, the principal bilateral air quality
issue, is the primary focus of work under the
Air Quality Agreement. Both countries have
made substantial progress in implementing
their respective acid rain control programs.
In accordance with Annex 1 of the Air Quality
Agreement, both countries undertook to
reduce emissions of sulphur dioxide (SO2)
and to implement caps on those emissions.
Canada's SO2 reduction program is well
established, with reductions ahead of schedule.
Canada has achieved about a 40 percent
decrease in SO2 emissions in the seven
eastern provinces from 1980 emission levels,
a reduction from 3,800 kilotonnes in 1980 to
2,316 kilotonnes in 1992, substantially meeting
its emissions target for eastern Canada two
years ahead of schedule. All major sources
targeted by the program have or will soon
complete technological improvements or
programs to reduce SO2 emissions and to
ensure that the 2,300 kilotonne cap will be
respected for the 1994-2000 period. Canada
is also committed to permanently capping
its national SO2 emissions at 3,200 kilotonnes,
beginning in the year 2000. Canada is currently
meeting this cap, with estimated national emis-
sions for 1993 reported at 3,040 kilotonnes.
In the United States, Title IV of the 1990
Clean Air Act (CAA) Amendments established
a national Acid Rain Program with a primary
goal of reducing annual SO2 emissions by
10 million tons below 1980 levels — a 40 per-
cent decrease in national emissions. Emission
reductions begin in 1995, and most reductions
will occur by the year 2000. When the Acid Rain
Program is fully implemented, a nationwide cap
of 8.95 million tons on utility SO2 emissions will
be maintained. Nonutility industrial sources of
SO2 will also be subject to a national emissions
cap of 5.6 million tons.
Since the last Progress Report, the U.S.
government and industry have undertaken
a major effort to implement the Acid Rain
Program. For example, the United States has
issued all of its major regulations. The utility
industry has installed continuous emission
monitors, submitted permit applications
and the first electronic reports on emissions,
increased use of flue gas desulphurization
units, contracted to switch fuel supplies,
participated in the SO2 allowance trading
market, and implemented a variety of energy
efficiency and conservation programs.
During the past two years, over 1 million SO2
allowances have either been sold at U.S. gov-
ernment auctions or exchanged in private trans-
actions. Overall, the U.S. Acid Rain Program
is clearly on track to achieve the goals set forth
in the CAA Amendments in a timely way.
Both countries committed to reductions
of nitrogen oxides (NOx) in Annex 1 of the
Agreement. In both cases, the reduction
goals amount to about 10 percent of national
emissions for both countries: 100,000 tonnes
in Canada and 2 million tons in the United
States. While the NOx reduction programs in
both countries are currently driven more by a
concern about ground-level ozone (smog) than
acid rain, both countries share a concern about
the role of nitrogen compounds in acidification
processes. NOx reduction programs are being
implemented in both countries for both station-
ary and mobile sources, including electric utility
plants and passenger cars.
Programs to
Address New Air Issues
In 1993, Canada created a National Air Issues
Steering Committee made up of federal
and provincial/territorial deputy ministers
responsible for the environment and energy.
The Committee, which has been meeting
regularly since its inception, facilitates consul-
tation with industry and nongovernmental
organizations on air issues, including acid
rain, smog, stratospheric ozone, climate
change, and particulate matter/visibility.
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In the United States, a new National
Science and Technology Council (NSTC)
was created in 1994. The Council has a
Committee on the Environment and Natural
Resources and Subcommittee on Air Quality.
The Subcommittee on Air Quality's role
is to integrate federal research programs
and priorities related to various air quality
issues, including acid rain, tropospheric
ozone, particulate matter/visibility, and
indoor air. The NSTC held its first public
forum in March 1994. The forum included
industry, the academic community,
and other interested parties.
Article V Notification
Canada and the United States have also
made headway in other activities that concern
notification procedures on transboundary
air pollution under Article V of the Air Quality
Agreement. The two countries formed a work
group and held discussions to address assess-
ment, notification, and mitigation of proposed
actions, activities or projects that, if carried
out, would be likely to cause significant
transboundary air pollution. Based on the
discussions, the Air Quality Committee
decided that each country would implement
its own notification procedures consistent
with the intent of Article V. Both countries
are also considering the development of
an electronic bulletin board on notification
that would be accessible to the public.
Scientific and
Technical Cooperation
Since the last Progress Report, the two
governments have made new inroads
in scientific and technical cooperation
on topics such as atmospheric modelling,
deposition monitoring, emissions inventories,
effects research and monitoring, control
technologies, and market-based incentives.
Key atmospheric modelling and deposition
monitoring findings and developments
include:
• The highest levels of wet sulphate
deposition for 1988 through 1991 occurred
in Ohio, Pennsylvania, and West Virginia,
while, in Canada, the southern parts of
Ontario and Quebec received more than
the Canadian target load of 20 kilograms
(kg) per hectare per year. The 20 kg target
load is expected to be reached with full
implementation of the Canadian and U.S.
acid rain control programs.
• A joint study to evaluate the Acid
Deposition and Oxidants Model and
the Regional Acid Deposition Model was
completed. The study showed that the
models could reasonably estimate current
and future rates of sulphur and nitrogen
deposition. Canadian and U.S. deposition
monitoring networks were improved by
taking into account information from the
models. In addition, nitrogen deposition
was added to published quantitative
estimates of the relative contributions
of Canadian and U.S. source regions
to receptor deposition.
Significant findings on aquatic ecosystem
trends include:
• Trends observed in the chemical records
of lakes and streams in areas that receive
high sulphate deposition demonstrate the
complexity of the response to SO2 controls.
For example, over the past decade, about
one third of monitored lakes in Canada
showed evidence of recovery while about
half that many continued to acidify.
Surveys and other experiments provide
some evidence of chemical and biological
improvements at locations where deposi-
tion has noticeably decreased, but only
high-quality, long-term monitoring records
will reliably quantify regional responses
to SO2 control.
• Lake monitoring in both Canada and the
United States shows that as acidification
decreases and lake pH increases, biological
populations recover, or can be re-established,
relatively rapidly (in less than a decade).
• Studies on the effects of episodic
acidification during snowmelt and rain-
storms in Adirondack and Appalachian
plateau streams in the United States clearly
demonstrate that episodic acidification can
have serious long-term adverse effects on
fish populations even in streams with suit-
able chemistry during low-flow conditions.
• Lake survey data shows increasing nitrate
concentrations in a number of lakes and
streams in the Adirondack and Catskill
Mountains of New York, the Mid-Appalachian
region, Ontario, and Quebec. These loca-
tions also receive some of the highest
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levels of nitrogen deposition in North
America. Maintenance of existing levels
or increases of nitrogen deposition over
the long term may eventually undermine
the ecological benefits derived from S02
control programs.
Forest effects studies show that there is
no large scale decline in the health of North
American forests. For example, the Canada-
U.S. North American Maple Project showed
that over 90 percent of trees sampled were
healthy and mortality rates were normal.
However, there are several areas of concern.
Over large areas of Ontario and Quebec, sugar
maples with no visible symptoms of decline
have experienced reduced growth rates over
the past 30 years. Forest research has also
shown adverse effects from acidic deposition
in local instances on certain species of trees.
For example, acidic cloud water in high-
elevation portions of the eastern United
States caused enough winter damage to red
spruce foliage to reduce growth rates and
cause increased mortality to trees. Similarly,
in southeastern New Brunswick, acid fog was
found to have caused serious deterioration
and death of white birch.
In the area of visibility, a technique has
been developed in Canada to extract addi-
tional information from historical visibility
data. This technique will be used to develop
maps describing visibility across Canada by
season and by year. These maps will serve
as the baseline against which future visibility
changes will be determined. Efforts are cur-
rently under way to merge the visibility data
sets from both Canada and the United States.
In other visibility developments, new trans-
port and transformation models were used
to predict future changes in visibility. With
full implementation of control programs in
Canada and the United States, a noticeable
improvement in visibility should occur across
the eastern United States and eastern Canada.
Reports on materials effects research show
clearly that pollutants, especially SO2, accel-
erate the degradation of building materials
exposed to the atmosphere. There is no evi-
dence of any critical level of pollutant below
which corrosion damage does not occur.
In health effects research, a five-year study
of more than 10,000 children in 24 North
American cities indicates a strong statistical
association between decreased lung function
and long-term exposure to ambient acidic
aerosols. Significant differences in acute
bronchitis between high- and low-acid
communities was also evident in this study.
Human clinical studies have also suggested
that asthmatics might be more sensitive
to short-term high-acid aerosol exposures.
Joint activities carried out to ensure that
the data collected under both countries' pro-
grams are comparable and have credibility.
Activities have been expanded to include
all three major wet deposition monitoring
networks — the National Dry Deposition
Network (NDDN), the Canadian Air and
Precipitation Monitoring Network (CAPMoN),
and the National Atmospheric Deposition Pro-
gram/ National Trends Network (NADP/NTN).
Several activities are also under way in both
countries to develop, demonstrate, and deploy
energy technologies to reduce emissions of
both S02 and NOx. Among the clean coal tech-
nologies being explored by Canada, is the
Integrated Coal Gasification Combined Cycle.
In the United States, 45 projects are under way
in the Clean Coal Technology Program repre-
senting a total investment of almost $7 billion.
Both countries remain interested in the use
of market-based mechanisms to achieve air
pollution reduction at lower cost to society.
The U.S. allowance trading system under the
Acid Rain Program is estimated to significant-
ly reduce the costs of compliance by industry
in the range of 25 to 50 percent.
In sum, both countries have made significant
progress in implementing their respective
acid rain control programs. The two countries
are also engaged in a host of technical and
scientific activities, including technology
demonstrations and deployments, the devel-
opment of emission inventories, atmospheric
modelling, depositions and effects monitoring,
and effects research. All of these activities are
an integral part of air quality management.
Both countries are undertaking an analysis
of ongoing problems to assess the need for
further actions to address air quality problems.
In addition, the two countries have established
new mechanisms to address air quality research
and programs in a more comprehensive and
coordinated manner. These activities include
examinations of the need for revisions to cur-
rent air quality standards (e.g., ground-level
ozone) and regional loadings programs (e.g.,
acid rain).
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SECTION I
Introduction
HISTORY OF THE AGREEMENT
In 1991, the signing of the Canada-United
States Air Quality Agreement signalled the
beginning of a new era of environmental
cooperation between the two countries.
A bilateral Air Quality Committee (AQC)
was subsequently established to address
problems on the issue of transboundary
air pollution.
The Canada-United States Air Quality
Committee includes two working subcom-
mittees. The Subcommittee on Program
Monitoring and Reporting works on such
issue areas as assessing progress toward
meeting emission reduction targets and
establishing specific implementation proce-
dures, emission inventories, and market-
based mechanisms. The Subcommittee on
Scientific Cooperation promotes information
exchange and cooperation in such areas
as atmospheric modelling and research
and monitoring of atmospheric, environ-
mental, and human health effects. The AQC
meets at least once a year to provide overall
direction to the subcommittees and to review
progress made.
The AQC published its first Progress Report
in March 1992, one year after the Agreement
was signed. The report provided a point of
reference for the work of the AQC and for
future progress reports. It described the steps
that led to the Agreement and the basis for
the acid rain programs in each country. It also
described the scientific and technical under-
pinnings of the programs as well as the state
of economic research on the subject of trans-
boundary air pollution.
Under Article IX of the Agreement, the
International Joint Commission (IJC) is
assigned implementation responsibilities.
Specifically, the IJC must:
• Invite comments on each progress report
prepared by the Air Quality Committee.
• Submit a synthesis of the views received
as well as the record of such views if either
country so requests.
• Release the synthesis of views to the public
after its submission to both governments.
PUBLIC COMMENT
ON THE 1992 PROGRESS REPORT
The IJC sent out letters inviting comment on
the 1992 Progress Report. Overall, the general
public appeared to be confused about the
reporting relationship of the Air Quality
Committee. Some people thought that it
reports to the IJC. In fact, the AQC reports to
the "Parties to the Agreement" (the Parties),
represented by the United States Secretary
of State and the Canadian Minister for
Foreign Affairs and International Trade.
The IJC is not a "Party to the Agreement,"
nor is it represented on the AQC. The IJC
serves as a knowledgeable third party,
responsible for seeking comments on the
progress reports prepared by the Committee
and assisting the Parties in the implementa-
tion of the Agreement.
Several respondents were strongly support-
ive of the Air Quality Agreement. Several
commented, however, that the report failed
to mention delays and obstacles in both
countries to achieving the goals established
in the Agreement. For example, some respon-
dents believed that target reductions for acid
deposition are not stringent enough to protect
lakes and soils in eastern Canada, even if the
terms of the Agreement are fully implemented.
Respondents strongly supported expanding
the scope of issues covered under the Agree-
ment to include other air quality problems,
including toxic air emissions and ground-
level ozone. Governments were encouraged
to develop cooperative arrangements under
the Agreement to ensure that these priority
issues receive the attention they require.
Since some of the emissions that contribute
to acid deposition are related to other envi-
ronmental concerns, including ground-level
ozone and greenhouse gas buildup, respon-
dents believed that programs to address
these issues should be integrated. This
approach might allow cost-sharing among
the programs. It also might produce multiple
benefits from the same strategies. Moreover,
it was suggested that future reports should
attempt to quantify the relative contributions
of energy conservation, efficiency, and
control to emission reductions.
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Many of the comments also addressed
specific aspects of the emission reduction,
effects, and research monitoring programs.
The AQC has assessed each comment. This
Progress Report responds to as many com-
ments as possible. Some of them have long-
term implications related to the workplan of
the AQC. For example, expansion of the scope
of issues covered under the Agreement is
being actively considered, taking into account
the state of scientific understanding of air
issues and their transboundary implications,
and the maturity and compatibility of individ-
ual programs. Readers are invited to submit
written comments or proposals to the co-chairs
of either the Subcommittee on Program
Monitoring and Reporting or the Subcommittee
on Scientific Cooperation. A copy of the report,
Synthesis of Views on the March 1992
Progress Report of the Air Quality Committee
under the United States-Canada Air Quality
Agreement, is available from the IJC.
AIR QUALITY COMMITTEE:
CURRENT ACTIVITIES
Since the first Progress Report, the AQC
met in November 1992 in Hull, Quebec,
and in December 1993, in Washington, DC.
The AQC requires that the subcommittees
report on progress, particularly in meeting
the emission reduction requirements as set
forth in the Agreement and on the initiation
of scientific research of mutually high priori-
ty. The status of these issues is addressed
in sections II and III of this report.
At the November 1992 meeting of the AQC,
the two countries addressed a mandate to
develop procedures for implementing Article
V under the Air Quality Agreement. Article V
addresses assessment, notification, and miti-
gation of sources that have the potential to
cause significant transboundary air pollution.
The Subcommittee on Program Monitoring
and Reporting met in October 1992 and in
April 1993. The Subcommittee reviewed
progress of implementation of respective
acid rain control programs and discussed
Article V issues and the development of
prevention of significant deterioration and
visibility protection programs in Canada.
Discussions on Article V were directed at
developing steps for ensuring timely and
accurate sharing of information on new
sources of emissions and their potential
impact on each country. The April meeting
also initiated discussions on existing ozone
regulations and related activities in Canada
and the United States. These are summarized
in Section IV of this report, which deals with
areas of future cooperation.
The Subcommittee on Scientific Cooperation
also met in October 1992 and in April 1993.
It reviewed the status of Canadian and U.S.
research efforts. Topics included atmospheric
monitoring and modelling, effects on aquatic
systems, forest ecosystems, visibility, materi-
als, human health, and quality assurance/
quality control. These meetings also included
presentations on ground-level ozone research
in both countries.
At the December 1993 meeting of the
Canada-U.S. Air Quality Committee in
Washington, DC, agreement was reached
about implementing Article V. Each country
will implement its own notification proce-
dures and advise the other of its intentions
through the AQC (Section II of this report
deals with progress under Article V). Other
discussions at the meeting centred on
Canadian and U.S. progress in implementing
their respective acid rain control programs,
joint efforts on scientific cooperation and
information exchange, cooperation on other
air issues (including ground-level ozone,
toxics, and particulate matter), the status
of the UN Economic Commission on Europe
Long-Range Transboundary Air Pollution
S02 Protocol, as well as future efforts.
Notes: The text of the 1994 Progress
Report uses Canadian spelling throughout,
e.g., sulphur instead of sulfur. Future Progress
Reports will alternate the use of Canadian and
American spelling. Dollars are US$ unless
otherwise indicated.
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SECTION II
Progress: Specific
Programs and Objectives
OVERVIEW
In an effort to reduce the impact of acidic
deposition on sensitive lakes, streams,
forests, materials, visibility, and human
health in Canada and the United States,
both countries have set out to meet goals
to reduce the levels of sulphur dioxide (S02)
and nitrogen oxides (NOx) emissions in their
respective countries. The emission reductions
outlined in Annex 1 of the Air Quality
Agreement (see Table 1) identify obligations
that Canada and the United States have under-
taken in their efforts to reduce SO2 and NOx,
the primary precursors of acid rain. (Table 1
summarizes the SO2 Emission Reduction
Goals for the United States and Canada. In
this table, and throughout the remainder of
this document, Canadian SO2 and NOx emis-
sions are expressed as metric tonnes [tonnes].
U.S. SO2 and NOx emissions are expressed
as short tons [tons]. One short ton is equiva-
lent to 0.9 metric tonne. One metric tonne
is equal to 1.1 short tons.) This section
discusses each country's implementation
progress in meeting the obligations of
the Air Quality Agreement.
IMPLEMENTATION
OF CONTROL PROGRAMS
Canada
Program Goals
Canada's SO2 reduction program is well
established, with reductions ahead of
schedule. Canada has cut SO2 emissions in
the seven easternmost provinces, which are
the most acid-sensitive, from 3,800 kilotonnes
in 1980 to 2,316 kilotonnes in 1992. This is
about a 40 percent decrease and substantially
meets the emissions target for eastern
Canada two years ahead of schedule. New
annual SO2 limits in three eastern provinces,
in addition to technological improvements
and SO2 reduction programs, will ensure that
Canada meets the 2,300 kilotonne (2.3 million
tonne) level for the 1994-2000 period.
issions reductiopjfgv
ost provin
S02 emissions reduction of
810 million tonsi from 1980
levels by the "year 20002
^Permanent national cap of 8.95
for electric utilities
r 2010 '-
oftaf cap ol 5.6 million tons
industrial sour
Canada is also committed to permanently
capping its national S02 emissions at 3,200
kilotonnes, beginning in the year 2000. Canada
is currently meeting this cap, with estimated
national emissions for 1993 reported at 3,040
kilotonnes. Canada is developing a long-term
acid rain strategy to ensure that the national
cap continues to be met and to ensure that
regions within the country are managed
according to their environmental sensitivities.
Table 2 illustrates SO2 reductions achieved
by 1992 as well as 1994 emission limits (some
of which are still being amended through on-
going federal/provincial negotiations to reflect
the 2,300 kilotonne limit).
For NOx reductions, Canada is committed to
a 100,000 tonne reduction in NOx emissions
from stationary sources in the year 2000.
The Canadian Control Program
Canada's control program has focused
on reducing emissions at large nonferrous-
metal smelters and fossil-fuel-burning power
plants. Implementation of the program has
taken almost a decade and involved research,
development, and demonstration of technolo-
gies to control acid gas and other emissions.
In Canada, the implementation of programs
to control air pollutant emissions, such as
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1980
Actual
Emissions Limit
Manitoba
Primary Metals
Other
Total2
Ontario
Primary Metals
Power Generation
Other
Total2
695
,167
233
1095
730
195
241
1166
1096
396
272
1764
Quebec
Primary Metats
Other
Total2
New Brunswick
Primary Metals
Power Generation
Other
Total2
Nova Scotia
Power Generation
Other
Total2
Newfoundland
Power Generation
Other
Total2-6'7
Prince Edward Island
Total2'4
Eastern Canada Total
Primary Metats
Power Generation
Other
2215
662
941
3818
1849
644
617
3110
1639
653
570
2862
1425
500
567
2492
1291
467
558
2316
1457
455
535
2447
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NOx and S02, and to address broader issues,
such as regional air quality problems like
smog, is a shared responsibility between
the federal and provincial governments.
In general, the federal government's role is
to deal with transboundary issues or circum-
stances where federal resources are implicat-
ed. The federal government also provides
leadership for the development of national
emission standards for new emission
sources. The provinces have a primary role
in overseeing the protection and manage-
ment of resources within their boundaries,
as well as developing and enforcing regula-
tions. Figure 1 shows Canada's compliance
strategy for 1980 to 1994.
Coordination among the provinces and
the federal government is done through
the Canadian Council of Ministers of the
Environment (CCME) and the Council
of Energy Ministers.
Canada's national power plant emissions
guidelines were revised and published in
1993 under the authority of the Canadian
Environmental Protection Act. These call
for stricter control of NOx at new and
existing modified plants and for continuous
emissions monitoring for both NOx and S02.
SO? Programs
New SO2 reductions have come largely
from the smelting sector (64 percent of all
reductions) followed by retiring old plants,
fuel substitution, and changes in industrial
processes (24 percent).
Highlights of S02 programs undertaken in
the provinces over the past two years are
as follows:
• Canadian electric utilities commissioned
three new coal-burning power plants
designed to meet national power plant S02
emission standards. The first, at Shand in
Saskatchewan, is equipped with limestone
injection into furnaces and activation of
unreacted calcium (LIFAC) S02 control
system, a North American first, to remove
65 percent of S02. The second, at Belledune
in New Brunswick, has a conventional
90 percent efficient wet limestone scrubber.
The third new power plant, at Point Aconi in
Nova Scotia, has the world's largest operating
Figure 1 Canada's S02 Compliance Strategies
Scrubbing at
power plants
Fuel switching
at power plants
Retirements, fuel
switching & process
changes in industry
Smelter
upgrades
Estimated reductions in SO2 emissions from 1980 to 1904
(1.6 million tonnes)
circulating fluidized-bed unit with limestone
injection to capture about 90 percent of S02
emissions.
• In the fall of 1993, Inco Ltd. completed a
C$600 million modernization of its Sudbury,
Ontario, Copper Cliff complex. This program
alone will cut emissions of S02 from 865
kilotonnes in 1980 to below 265 kilotonnes
in 1994.
• Hudson Bay Mining and Smelting is mod-
ernizing its Flin Flon, Manitoba, complex.
A new hydrometallurgical pressure leach
process will replace the old zinc smelter and
a Noranda Continuous Reactor will be used
to smelt copper. These programs will ensure
that emissions will not exceed the plant's
220 kilotonne limit and will allow for future
additional S02 capture as a by-product.
• The Noranda Metals Home smelter at
Rouyn-Noranda, Quebec, completed its
first round of major S02 reductions in late
1989 and is continuing to improve the rate
of emissions capture. Its program has cut
emissions from 550 kilotonnes in 1980 to
below the regulatory limit of 272 kilotonnes.
• Existing power plants in New Brunswick
and Ontario, with about 1,300 megawatts
of existing capacity, are being equipped with
wet limestone scrubbers. The first Ontario
scrubber began operation in June 1994.
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NOx Reductions
New programs for NOx reduction are
being implemented:
• New federal guidelines for stationary
combustion turbines were published in
December 1992 that are extensively used
in new power generation systems. The
guidelines are based on overall plant
energy efficiency and could result in a
50 to 80 percent reduction in uncontrolled
NOx emissions from engines approved for
installation after November 1994.
• NOx/volatile organic compounds (VOCs)
control initiatives include adopting new
NOx emission standards for motor vehicles
and appliances; revising building code
requirements for enhanced home insulation;
using demand-side management plans for
power generation; and conducting public
education on energy conservation, trans-
portation alternatives, vehicle maintenance,
and driving habits.
• The first selective catalytic reduction unit
in a Canadian power plant was approved
for installation on the gas-fired Burrard
power plant in British Columbia.
• Published revised federal guidelines for
fossil-fuelled power plants in May 1993
(see Table 3).
British Columbia has already started imple-
menting other reduction programs with the
commissioning of inspection and mainte-
nance stations to reduce light-duty vehicle
emissions in the Vancouver area. In Ontario,
Ontario Hydro published a plan to reduce NOx
emissions from power plants by 30 percent
by the year 2000. Quebec amended its Air
Quality Regulation to include the national
prevention elements of the ground-level
ozone reduction program. New Brunswick
imposed new national standards on one new
power plant and one is undergoing a major
modification. It is still too early to quantify
the actual reductions based on inventories.
A preliminary outlook forecast that includes
the effects of the expected emission reduc-
tions, however, shows that Canada will
meet its commitment to reduce its stationary
NOx emissions by 100 kilotonnes by 1999.
Additional initiatives are or will be developed
to retrofit existing stationary sources such
as power boilers, commercial/industrial
boilers, existing turbines, and process
heaters in refineries, petrochemical plants,
steel foundries, and other industries. New
source performance standards are in effect
now and implementation is required to
be completed in 2000 for these retrofits.
Efforts to reduce NOx emissions in Canada
are also aimed at reducing ground-level
ozone. NOx emissions from stationary, area,
and mobile sources are being inventoried.
Control strategies and measures identified
by the Canadian Council of Ministers of the
Environment NOx/VOC Management Plan
are being developed. In addition, VOC emis-
sions, another cause of ground-level ozone,
are being addressed. Control initiatives,
studies, and scientific knowledge are being
developed in an effort to meet Canada's
ambient air quality objective of 82 parts
per billion (ppb) of ozone by the year 2005.
Progress has been made in programs to
monitor industry's compliance in reducing
emissions. Compliance monitoring involves
measuring or estimating emissions, verifying
that the values are accurate, and reporting
the results to regulators on a regular basis.
In Canada, emissions may be estimated
based on process variables such as tonnes
of ore processed or sulphur recovered per
unit of time, or they can be directly measured
on a continuous basis. Continuous emission
monitoring (CEM) is the measurement, on
a continuous basis, of pollutants emitted
into the atmosphere in exhaust gases from
combustion processes or as the by-product
of industrial processes. The relative cost
and site-specific technical factors determine
which approach is used.
For Canada's new fossil-fuelled power plants,
national guidelines revised in 1993 call for
installation of CEM systems and the monitor-
ing of NOx and SO2. This is to be done in
10
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accordance with Protocols and Performance
Specifications for Continuous Monitoring
of Gaseous Emissions from Thermal Power
Generation, also published by Environment
Canada in 1993. These CEM specifications
draw upon experience gained from develop-
ment of the U.S. Environmental Protection
Agency's (EPA) CEM standards as well as
the International Standards Organization
standards. The specifications were devel-
oped in consultation with the provinces
and the electric power industry and are
expected to be widely used by these groups
as the basis for CEM system installation
and operation.
To promote the implementation of CEM
at Canadian coal-burning power plants and
in other industries. Environment Canada is
sponsoring technical seminars that are being
well attended by industry and government
personnel. Canadian electric utilities and
provincial regulators are developing and/or
implementing CEM-based compliance moni-
toring programs at most major coal-burning
power plants. For plants that are operated
infrequently, alternative methods for reliable
emissions estimating are being investigated
by government and industry.
In addition to electric power utility plants,
alternative emissions monitoring methods
are being investigated for other Canadian
stationary emissions sources such as metals
smelters, natural gas processing plants,
combustion turbines and small boilers. As
CEM systems become more common, eco-
nomical, and reliable, their use is expected
to grow, particularly when they can also
provide opportunities for better industrial
process control.
Environment Canada will be publishing
the results of its investigations and recom-
mended approaches later in 1994. For small
sources, such as boilers, Environment Canada
is working with the provinces and industry
to develop alternatives to direct monitoring
in order to quantify emissions. One alternative
being considered is an improved inventory
of engines, boilers, and other stationary
emissions sources, including fuel use and
other parameters.
United States
Program Goals
The goal of the Acid Rain Program in the
United States is to achieve significant envi-
ronmental benefits through reductions in
emissions of S02 and NOx. Title IV of the
Clean Air Act (CAA) Amendments sets as
its primary goal the reduction of annual
SO2 emissions by 10 million tons below
1980 levels, with utility emissions subject
to a national cap of 8.95 million tons per
year and a national cap on nonutility emis-
sions of 5.6 million tons. This goal is to be
accomplished in two phases, with Phase I
beginning in January 1995. The Act also
calls for a 2 million ton reduction in NOx
emissions by the year 2000.
Four key features of the Acid Rain Program
are: (1) an innovative, market-based banking
and trading system of emission allowances;
(2) flexibility for electric utilities to choose
the most efficient and cost-effective tech-
nologies; (3) a national cap on emissions;
and (4) accountability through continuous
emission monitoring. EPA is responsible
for implementing the Acid Rain Program.
Under the program, S02 emissions allowances
are allocated to affected utility units based on
their historic fuel consumption and a specific
emission rate. Each allowance permits a unit
to emit one ton of SO2 during or after a speci-
fied year. Affected units must hold a sufficient
number of allowances at the end of the year
to cover their annual emissions. Once allocat-
ed, allowances are fully marketable. In making
their compliance decisions, utilities can buy,
sell, or bank allowances for future use (Figure 2).
Utilities are penalized for noncompliance.
To ensure compliance with the Acid Rain
Program, affected electric utilities must file
permit applications and measure and report
all emissions. Individual units determine
their own compliance strategy from among
several or a combination of options, such as
allowance trading, repowering units, using
a cleaner-burning fuel, or reassigning energy
production from dirtier units to cleaner ones.
Sources can also install scrubber equipment
or adopt energy-efficient measures.
11
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Figure 2
U.S. SO, Compliance Strategies
Reported for Phase I
11.2%
11.2%
85.6
11.2%
0.7%
ling I
| Trading _i Scrubbing | Fuel Switching
I Reduced Utilization U No Action Needed
Phase I begins in January 1995 and affects
110 mostly coal-burning electric utility plants
(263 units) located in 21 eastern and mid-
western states. Phase II, which begins in the
year 2000, tightens the annual allowance allo-
cations for these large plants and also sets
allocations for approximately 700 additional
plants (approximately 2,100 units). These
Phase II plants are generally cleaner than the
Phase I plants, and are fired by coal, oil, and
gas. The program affects all existing utility
boilers and turbines serving generators
with an output capacity of greater than
25 megawatts as well as all new utility units.
In 2010, when the Acid Rain Program is fully
implemented, a nationwide cap of 8.95 million
S02 allowances per year on utility units will
be maintained.
SO, Program Implementation
The U.S. Acid Rain Program has an integrated
set of rules and guidance. The major rules
were published in January 1993. Phase I of
the S02 emissions reduction program begins
in January 1995 and its implementation is
well underway. All 110 Phase I utility sources
submitted permit applications. Seventy-two
Phase II sources also are considering entering
the Phase I program ahead of schedule. All
draft permits were issued by August 1993,
with final permits issued by August 1994.
EPA reviewed Phase I permit applications
from utility plants and concluded that approx-
imately 200,000 excess allowances could be
generated under the existing acid rain rules.
In November 1993, EPA proposed revisions
to the rules for substitution and reduced uti-
lization to correct this problem. A settlement
agreement was reached in May 1994 with
petitioners who had challenged the January
1993 rules. A revised final rule reflecting
the settlement and ensuring that no excess
allowances are created is expected to be
issued in the fall of 1994.
Allowance Trading
In other implementation initiatives, the
allowance trading system is receiving early
support from industry. Anticipating the first
year of compliance in 1995, utilities have
already begun trading emissions allowances.
Over 20 two-party and brokered trades have
been reported, involving the sale of over
1 million allowances valued at over $200
million. Announced prices ranged from $200
to $300 per ton. Two annual public auctions
of allowances have been held. On March 29,
1993, over 150,000 allowances were sold
with prices ranging from $122 to $450 per
allowance. On March 22, 1994, over 176,000
allowances were sold, with prices ranging
from $140 to $400. The Chicago Board of
Trade has been authorized by EPA to run
these allowance auctions. The official
recording of allowances by EPA's Allowance
Tracking System, which opened March 14,
1994, is expected to facilitate more trading
in private allowances because it provides
validation for the issuance, holding, and
transfer of allowances.
Several companies also are providing broker-
age services and electronic posting of private
bids and offers. Private auctions are expected
to occur now that EPA's Allowance Tracking
System is in place.
Other program initiatives include EPA awards
of the first allowances from the Conservation
and Renewable Energy Reserve to utilities
that reduced emissions through the use
of energy efficiency and renewable projects
ahead of the CAA Amendments emissions
reduction deadlines. Utilities awarded bonus
allowances can sell them, bank them for
future use, or use them to comply with EPA's
acid rain rules. Unlike some other compliance
strategies, energy efficiency and renewable
12
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energy efforts reduce other air pollutants
(carbon dioxide, NOx, toxics, particulates),
water contaminants, and solid waste,
in addition to SO2.
NOx Program Implementation
The CAA Amendments also require additional
reductions of NOx emissions in the United
States. The amendments call for a 2 million
ton reduction in NOx emissions by the year
2000. The NOx reductions will be achieved
through a combination of measures for mobile
and stationary sources. The CAA Amendments
mark the first time that federal laws have
required NOx reductions from existing
stationary sources of air pollution. Previous
requirements addressed NOx reduction only
through controls on motor vehicles and new
utility and industrial sources.
NOx reductions under the U.S. Acid Rain
Program will be achieved in two phases.
Under regulations established in March 1994,
Group 1 boilers (defined as coal burning, dry
bottom wall-fired and tangentially fired boil-
ers) covered under Phase I must meet specific
performance standards by January 1, 1995.
About one quarter of all Group 1 boilers are
covered in Phase I. In 1997, EPA may set NOx
performance standards for all other coal-fired
utility boilers (Group 2) as well as more strin-
gent standards for dry bottom wall-fired and
tangentially fired boilers if effective low-NOx
burner technology is available.
EPA limits annual emissions of NOx to
0.050 pounds per million Btu for dry bottom
wall-fired boilers, and 0.45 pounds NOx per
million Btu for tangentially fired boilers. These
limits for Group 1 boilers are achievable with
commercially available technologies. The NOx
rule also establishes procedures allowing utili-
ties to average emissions among certain
affected units.
Each affected unit can choose from among
several NOx emission reduction technologies
to comply with the applicable proposed emis-
sion limitation. These include low-NOx burner
technology, alternative control technologies,
fuel switching, and changes to boiler operat-
ing parameters. Utilities can select the most
cost-effective NOx emission control strategy.
This flexible approach also promotes technol-
ogy development and encourages market
competition among vendors.
On November 25, 1992, EPA provided guid-
ance to states on implementing stationary
source NOx control requirements for reducing
ground-level ozone (smog) in parts of the
United States that have exceeded the health
standards for ozone in urban nonattainment
areas and the Northeast. EPA guidance to
states is generally consistent with a National
Academy of Sciences study required by the
CAA Amendments and issued in December
1991. The study concluded that NOx reduction
is necessary for effective reduction of ozone
in many areas of the United States. Both Title
II of the CAA Amendments and Annex 1 of the
Air Quality Agreement focus on NOx emission
reductions from mobile sources, emphasizing
new vehicle emission limits.
EPA issued regulations with an emphasis on
implementing the mobile source provisions in
June 1991. The new NOx limits for light-duty
vehicles (passenger cars and some light-duty
trucks) are being phased-in. In model year
1994, 40 percent of each manufacturer's sales
volume of passenger cars and light-duty
trucks under 6,000 pounds must meet a stan-
dard of 0.4 grams per mile (gpm). In 1995,
the percentage increases to 80 percent. In
model year 1996,100 percent of these light-
duty vehicles must meet the standard. In addi-
tion, in model year 1966, 50 percent of each
manufacturer's sales volume of light-duty
trucks over 6,000 pounds must meet a stan-
dard of 0.7 gpm; in 1997, 100 percent of light-
duty trucks in this category must meet the
standard. For heavy-duty trucks, phase-in
of NOx limits began in 1991, with full imple-
mentation by 1998. Other regulations limiting
NOx emissions for nonroad diesel engines
(e.g., railroad engines) and farming and con-
struction equipment were issued in May 1994.
Monitoring of U.S. Emissions
Continuous emission monitoring is
critical to the Acid Rain Program. It instills
confidence in allowance transactions by
certifying the existence and quantity of
the commodity being traded. Monitoring
also ensures, through accurate accounting,
that the emissions reduction goals of the
1990 CAA Amendments are met. All Phase I
utilities completed certification testing and
began submitting quarterly reports to EPA
in January 1994. Phase II utilities will complete
13
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Worker tests
continuous
emission
monitoring
equipment on
an American
electric utility
plant.
the certification tests for all coal-fired utilities
by the end of 1994 and begin submitting
quarterly emissions reports by April 1995.
Unlike traditional regulatory programs,
which measure specific emission rates, the
Acid Rain Program focuses attention on total
emissions. The Acid Rain Program requires
an accounting of each ton of S02 emissions
from each regulated unit. Each regulated unit
must install a CEM system, which includes
an S02 pollutant concentration monitor, a
NOx pollutant concentration monitor, a volu-
metric flow monitor, an opacity monitor,
a diluent gas (oxygen or C02) monitor, and
a data acquisition and handling system for
recordkeeping and performing calculations
with the data. C02 emissions data also are
collected for the purposes of gathering infor-
mation on climate change. All CEM systems
must be in continuous operation and must
be able to sample, analyze, and record data
at least every 15 minutes. All emissions and
flow data will be reduced to one-hour aver-
ages. Regulated units are required to provide
electronic quarterly reports to EPA on their
emissions. Each new electric utility unit and
each existing electric utility unit greater than
25 megawatts must employ such a CEM sys-
tem; there are alternative monitoring require-
ments for some natural gas and oil-fired units.
PREVENTION OF
SIGNIFICANT DETERIORATION
AND VISIBILITY PROTECTION
Information Exchange
Meetings Between Canada
and the United States
In 1993, several meetings and conference
calls took place between EPA, the National
Park Service (NPS), the U.S. Fish and Wildlife
Service (FWS), Environment Canada, and
Heritage Canada. Canada and the United
States also met in New Brunswick to
exchange information on activities regarding
air monitoring, acid precipitation monitoring,
visibility monitoring, and biological effects
research programs in national parks and
wildlife refuges. Planning and management
issues discussed at the meeting included air
quality management, park planning and inter-
governmental activities, and both Canadian
and U.S. park systems' involvement in the
Air Quality Agreement.
Status of Development
of Prevention of Significant
Deterioration and Visibility
Programs in Canada
Canada has established a federal-provincial
National Prevention of Significant Deterioration
(PSDWisibility Working Group. The mandate
of the group is to define Canada's response
to meeting the PSD/visibility commitment for
Canada under Annex 1, paragraph 4, of the
Canada-U.S. Air Quality Agreement. Under
the mandate, by January 1, 1995, Canada must
develop and implement strategies to prevent
significant air quality deterioration and protect
visibility comparable to the U.S. PSD/visibility
program for sources that could cause signifi-
cant transboundary air pollution.
In Canada, environmental assessment
legislation exists at provincial and federal
levels, with differences in detail. The federal-
provincial Working Group investigated the
levels of protection offered by Canadian
environmental assessment procedures. The
Working Group will determine if existing
environmental assessment legislation pro-
vides a level of protection comparable with
the U.S. PSD/visibility program.
14
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Progress of Existing
PSD and Visibility Programs
in the United States
Since the 1992 Progress Report, several mod-
elling techniques have been made available
to assess the impacts of air pollution sources
on Class I areas (national parks and wilder-
ness areas). EPA's PLUVUE II model is aimed
at assessing the impact to Class I areas from
a single source. In addition, EPA, federal land
managers (the U.S. Park Service and U.S.
Forest Service), and the FWS have formed
the Interagency Workgroup on Air Quality
Modelling (IWAQM). This work group has
recently completed its Phase I report, which
provides information on appropriate "off-the-
shelf" methods for estimating long-range
transport impacts of air pollutants on federal
Class I areas and on regional visibility. These
techniques for assessing visibility in Class I
areas are continuing to undergo review and
further development. Refinements and new
developments may be expected in the future.
In monitoring activities since the last Canada-
U.S. Progress Report, an analysis of 1988-1991
monitoring data for Class I areas from the
Interagency Monitoring of Protected Visual
Environments (IMPROVE) network was issued
in February 1993. IMPROVE monitoring was
established in the mid-1980s by EPA, federal
land managers, and certain states.
In other activities, the Grand Canyon Visibility
Transport Commission, established under the
authority of the 1990 CAA Amendments, has
laid the initial groundwork for establishing
a database on visibility problems caused by
interstate transportation of air pollution in
national parks and wilderness areas on the
Colorado Plateau in the southwestern United
States. The Commission, made up of gover-
nors in states in the Air Transport Region and
ex-officio members from EPA and agencies
managing affected federal lands, has been
evaluating regional visibility problems and
is working to develop visibility management
policy options by November 1995. The
Commission has adopted use of the deciview
as a measure of haze to gauge the effects of
various strategies. The deciview is patterned
after the decibel, used to measure sound.
In other programs, EPA, in consultation with
representatives from industry, state and local
agencies, public interest organizations, and
the federal land managers, is in the process
of developing a strategy to implement New
Source Review Reform to streamline the
present process.
In addition, EPA released a Report to
Congress in October 1993 on the impact
of the CAA Amendments on visibility in
Class I areas. The study reaffirms that the
bulk of anthropogenic visibility impairment in
the eastern United States is due to sulphates,
the majority of which are emitted by power
plants. In relatively clean areas of the West,
where no single source category dominates
visibility impairment, small increases in pol-
lutant levels can markedly degrade visibility.
Visibility in Class I areas in the West, there-
fore, is particularly sensitive to increased
levels of pollution.
Implementation of the CAA Amendments
is expected to produce increases in annual
average visual ranges from 5 to 15 percent
in Florida, New England, and just east of the
Mississippi River to 25 to 35 percent in the
mid-Appalachians and the Ohio Valley. The
study also looked at numerous Class I areas
in the West. Consistent with relatively slight
changes in projected emissions of S02, NOx,
and particulates between the years 1988 and
2005, annual average visibility is expected to
remain stable in the western United States.
NEW ISSUES UNDER THE
CONTROL PROGRAMS
Canadian Air Issues
Committee
All jurisdictions within Canada have a long-
term objective of resolving, to the extent prac-
ticable and economically feasible, acidification
and other adverse effects of SO2 emissions.
The key issue for the long-term management
of S02 emissions in Canada is the nature and
timing of jurisdictional commitments for
achieving the 3.2 million tonne cap.
A number of important factors will be
considered over the next few years:
• Determining the need to further reduce sul-
phate deposition in eastern Canada beyond
levels that will be achieved with current
domestic and U.S. programs, establishing
target loads, and setting a schedule for
compliance.
15
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• Identifying driving forces, other than acidi-
fication, to protect the Canadian environ-
ment from the impacts of S02 emissions.
Such driving forces may be, for example,
the protection of human health or the
deterioration of visibility.
• Determining whether the role of nitrogen
in acidification is sufficiently important
to warrant further controls to minimize
acidification.
• Analyzing the benefits of an S02 man-
agement system designed to achieve
the national cap to determine if it also
can be designed to:
- contain strong cause-and-effect linkages;
- maximize cost effectiveness;
- promote pollution prevention;
- support harmonization commitments
in international agreements.
This work is being undertaken by Canada's
National Air Issues Steering Committee,
which has been meeting regularly since
it was established in 1993. Its membership
consists of federal and provincial/territorial
deputy ministers of environment and energy.
In the future, the Committee will deal with
emerging air quality issues, including
hazardous air pollutants.
U.S. National Science
and Technology Council
In the United States, a new National Science
and Technology Council (NSTC) was created
in 1994. The Council has a Committee on
the Environment and Natural Resources
and a Subcommittee on Air Quality. The
Subcommittee on Air Quality oversees inte-
grated research programs and priorities relat-
ed to various air quality issues, including acid
rain, tropospheric ozone, particulate matter/
visibility, and indoor air. The NSTC held its
first public forum in March 1994.
Acid Deposition
Standards Study
Under Title IV of the 1990 CAA Amendments,
EPA is preparing a Report to Congress on
the feasibility and effectiveness of setting
and implementing acid deposition standards
to protect sensitive water and land resources.
The purpose of this study is to assess the
residual risk to ecosystems following imple-
mentation of the CAA Amendments. An acid
deposition standard is a numerical limitation
on the amount of acidic compounds above
which adverse impacts are believed to occur
to a given ecological resource. The study
will integrate state-of-the-art ecological
effects research, emissions and source-
receptor modelling work and also consider
implementation and cost issues. The study
is expected to be completed in late summer
1994, and then made available for a 30 day
public comment period. EPA anticipates
delivery of the Report to Congress by
January 1995.
PROGRESS UNDER ARTICLE V
OF THE AIR QUALITY AGREEMENT
Article V addresses the assessment, notifi-
cation, and mitigation of proposed actions,
activities, or projects that, if carried out,
would be likely to cause significant trans-
boundary air pollution. The Agreement does
not contain specific procedures for imple-
menting Article V. Thus, at the November
1992 Air Quality Committee meeting a work-
ing group was formed under the auspices
of the Subcommittee on Program Monitoring
and Reporting to develop the specific proce-
dures for implementing Article V. At the
Committee's request, the Subcommittee
was to have a final draft of the procedures
for Committee review and approval by the
fall of 1993.
During 1993, discussions were held to identi-
fy issues associated with implementation of
Article V. From the outset, the discussions
were marked by a fundamental disagreement
on the interpretation of paragraph 1 of Article
V, which relates to assessment of sources,
as deferring to existing laws, regulations,
and policies in the respective countries.
Efforts turned to developing a joint notifi-
cation procedure. The ensuing discussions
were fruitful, and some progress was made
in this area. For example, both countries
agreed that major sources of S02, nitrogen
dioxide (NO2), VOCs, particulates, carbon
monoxide (CO), and toxic substances should
be subject to notification. Both parties agreed
on criteria for determining notification: (1) size
cutoff, tons (tonnes) per year of pollutant
emitted; and (2) distance from the border. In
addition, both parties agreed that information
-------
on sources subject to notification should be
available to the public. Canadian and U.S.
representatives could not reach agreement
on a joint notification process prior to
the Air Quality Committee meeting on
December 14, 1993.
The Committee concluded that it was proba-
bly not practical in the short term to imple-
ment joint notification procedures, given
the complexities of the legal differences in
each country. The Committee decided that
each country should develop its own notifi-
cation procedures and advise the other of its
intentions through the Air Quality Committee.
Meanwhile, each country will notify the other
of proposed actions, activities, or projects,
that, if carried out, would be likely to cause
significant transboundary air pollution.
Serious consideration is also being given
to setting up an electronic bulletin board
that would be accessible to the public.
17
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SECTION III
Progress: Scientific and Technical
Activities and Economic Research
In accordance with Annex 2 of the Air Quality
Agreement, Canadian and American scien-
tists have been coordinating and cooperating
on acid deposition modelling, monitoring,
and effects research for a number of years.
Recently, the two countries expanded their
cooperative efforts to include ground-level
ozone and visibility impairment.
In this section (as elsewhere in the report), the
terms acid rain and acid deposition are used
interchangeably. "Acid rain" is a shorthand
descriptor that has been used for many years
and has gained widespread public recogni-
tion. The problem of acidification is more
complex than the term acid rain would imply.
"Acid deposition," therefore, in addition to
encompassing wet deposition of acidic
species, also includes dry deposition of acidic
materials and atmospheric transformation
and transport contributing to the impact
these materials have on the environment.
EMISSION INVENTORIES
Emission inventories provide the foundation
for air quality management programs. They
are used to identify the major sources of air
pollution, provide data for input into air quality
models, and enable the tracking of control
strategies. The importance of emission inven-
tories and the accuracy of their estimates has
always been a priority in Canada and the
United States. Both countries have been
updating and improving their estimates for
the 1990 inventory using the latest informa-
tion obtained from states/provinces, source
measurements, and special study findings.
Numerous tools also have been developed
to analyze trends and forecasts of emissions.
Biannual meetings are continuing, emphasiz-
ing the need to pursue and increase the level
of collaboration between the two countries.
SULPHUR DIOXIDE, NITROGEN
OXIDES, AND VOC EMISSIONS IN
CANADA AND THE UNITED STATES
FROM 1980 TO 2010
Sulphur dioxide (S02) and nitrogen oxides
(NOx) emissions are the dominant precursors
of acid rain. NOx along with volatile organic
compounds (VOCs) are important contribu-
tors to the formation of ground-level ozone,
which also contributes to the formation
of acidic compounds in the atmosphere.
19
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The totals for all three pollutants covered in
this report were derived using methodology
that has been extensively revised from the
methodology used to develop previous
estimates. Using the revised methodology,
previous estimates have been recalculated.
Regarding U.S. mobile sources, the emission
estimates were revised using an updated
version of the mobile source emission
factor model (MOBILE 5). Enhancements
include emission factors that were adjusted
to account for currently used fuels, the use
of nine vehicle speeds (instead of three)
to obtain a more accurate model of real-
life highway conditions, and the addition
of late-model light-duty vehicles.
In addition, EPA's Office of Mobile Sources
conducted an extensive off-highway emis-
sions VOCs data survey in 1990 that produced
more accurate estimates over last year's
totals. Various source categories, including
solvent, fossil-fuel, steam-utility, and other
point sources, were re-estimated using
U.S. Department of Commerce Bureau of
Economic Analysis growth factor indicators
as well as the application of new control
efficiencies, rule effectiveness factors,
and updated emission factors.
The emission estimates for the years 1980,
1985,1990, and 1992 and the projected emis-
sion estimates for the years 2000 and 2010
are described for each pollutant in the sections
which follow. These estimates and projections
of the pollutant emission levels may vary from
year to year because of modelling develop-
ments. In addition, the 1990 and 1992 data
reported for both Canada and the United
States are preliminary. The 1980 data are
included because 1980 is the base year for
measuring emission reductions under the
acid rain control programs in both countries.
Table 4 summarizes the 1992 emission
estimates for Canada and the United States.
The estimates are divided into four major
categories, with the data presented both in
metric tonnes and short tons. Figures 3,
4, and 5 summarize the S02, NOx, and VOC
emission estimates for 1980,1985, 1990, 1992,
2000, 2005, and 2010. The data presented
in these figures and Table 4 were obtained
from EPA National Air Pollution Emission
Estimates, 1900-1992, October 1993, (EPA-
454/R-93-032) and from Environment Canada
(Pollution Data Analysis Division).
(million
tonnes1)
(mUhorv
tonnes)
(milfion-
•tons)-
(mipon
tonnes)
United States
Electric Utilities
Electric Utilities
U.S./Canadian Total
* One tern Is equal to O&liWUM^Jjiijt
2 Total is not the raw data total of i
r '
11. J ,* . : f f^-S , # , *l*Cy* , * 4?*1 * jtfKXSf ^"^.
-------
Sulphur Dioxide
The principal anthropogenic sources of S02
are coal and oil combustion, smelting, and a
few industrial processes. As shown in Table 4,
electric utilities were responsible for 70 per-
cent of the 1992 S02 emissions in the United
States and 23 percent in Canada, while indus-
trial sources were responsible for 23 percent
of S02 emissions in the United States and
61 percent of total S02 emissions in Canada.
Canadian S02 emissions were approximately
13 percent of the total emissions of Canada
and the United States combined in 1992;
U.S. emissions were approximately
87 percent of the combined total.
S02 emissions are declining. Overall trends in
emission levels from 1980 to 2010 for Canada
and the United States are presented in Figure
3. In 1980, total estimated emissions of S02
in the two countries were 28.5 million tonnes.
In 1985, total estimated emissions of S02 in
Canada and the United States were 25.1 million
tonnes. From 1980 to 1992, emissions of S02
in North America were estimated to decline
by 4.7 million tonnes, or 16.5 percent. S02
emissions in the United States in 2000 and
2010 are projected to be 18.3 million tons
and 16.3 million tons, respectively. The totals
include emissions from banked or unused
allowance credits. SO2 emissions in Canada
in 2000 and 2010 are projected to be 3.0 million
and 3.1 million tonnes, respectively. Uncertainty
bands on the national annual emissions esti-
mates of SO2 range from 5 to 10 percent; the
uncertainty bands are larger for regional
annual emissions estimates.
Figure 3 S02 Emission Estimates
30
o
1
01
33
M
a
+*
22 §
M
O
n 8
E
0
1980 1985 1990 1995 2000 2005 2010
Total • United States A Canada
— estimated emissions - - - projected emissions I
While 8.95 million S02 allowances are
expected to be allocated by 2010, the United
States' S02 emissions are expected to exceed
the national utility cap of 8.95 million tons
because utilities in Phase II are projected to
use banked allowances (or credits) gained
from greater emission reductions in Phase I.
Nitrogen Oxides
The principal anthropogenic source of emis-
sions of NOx is fuel combustion, which occurs
in internal combustion engines, residential
and commercial furnaces, industrial boilers,
electric utility boilers and engines, and other
miscellaneous equipment. As shown in Table
4, in 1992 45 percent of NOx emissions in the
United States and 60 percent of emissions in
Canada were produced by mobile sources.
Electric utilities were responsible for 32 per-
cent of the 1992 emissions in the United
States and 14 percent in Canada. Industrial
sources were responsible for 19 percent of
NOx emissions in the United States and
23 percent of total NOx emissions in Canada.
Canadian NOx emissions were approximately
9 percent of total emissions in the United
States and Canada combined in 1992; U.S.
emissions were approximately 91 percent
of the combined total.
21
-------
Figure 4 NOx Emission Estimates
million tonnes)
IS» W
o o
(A
o
8 10
E
UJ
o-l
19
kH" — * — .~* "••-.• ..---•'
"• — "*"*"•--. " . - - - -'
*"
80 1985 1990 1995 2000 2005 20
• Total • United States A Canada
estimated emissions - - - projected emissions
33
c
i 5
•22 g
E
o
11 (A
UJ
0
10
Note: For NOx emissions, these projections incorporate mandatory CAA measures for stationary
and mobile sources. The projections do not include measures that will be taken by individual
states to meet the National Ambient Air Quality Standard for ground-level ozone. These
additional measures will act to lower future emissions.
Figure 5 VOC Emission Estimates
30-,
"3>
1 '
o
§ 20
1
(A
O
8 10
E
UJ
o-l
19
Note: For
stationary
individual
These adc
Xtr^
*^* .
J*
80 1985 1990 1995
""• .. .......i
• '
" * A
2000 2005 20
• Total • United
States A Canada
- - projected emissions
33
"3T
o
22 §
i =
. I
o
11 <"
n
-------
to decline even further after 1992. Estimated
emissions for the United States in 2000 are
17.7 million tons and in 2010 are 17.5 million
tons. Emissions of VOCs in Canada in 2000
and 2010 are projected to reach 2.1 million
tonnes and 2.4 million tonnes, respectively.
Uncertainty bands on anthropogenic and
natural emissions of VOCs are large.
Ammonia
Natural and anthropogenic emissions of
ammonia are important in the study of
acidic deposition for a number of reasons: (1)
ammonia is a nitrogen-containing compound
and the deposition of ammonia contributes
to the total loading of nitrogen in the envi-
ronment; and (2) in the atmosphere, ammo-
nia can neutralize acidic substances. This
Progress Report, however, does not consider
the sources, emission trends, or projected
emission levels for ammonia.
Nonetheless, research on ammonia emission
factors has been conducted by EPA (and cer-
tain international groups) and the Agency is
currently conducting a literature search so that
the latest information can be assessed. Using
this information, EPA will develop a brief
research plan that identifies source categories
in need of more study. Additional categories
of research will be based on several factors,
including: (1) the limited test data available
for studying large-scale national and global
ammonia emissions; (2) significant industrial
process changes; and (3) controversy due to
the current emissions factor or activity data.
Conclusion
An overall trend of decreasing emissions
can be seen from this analysis, despite the
increases in the estimated emissions for cer-
tain individual sources. For example, 1992
saw increased consumption of bituminous
coal by electric utilities and industrial boilers
and the decreased use of other fuels (e.g.,
sub-bituminous coal, oil, and gas) in the
United States. The result was an estimated
net decrease in SO2 emissions. Total VOC
emission estimates in the United States
decreased from 1980 to 1992, due largely
to changes in automotive fleets. While
vehicle miles travelled rose approximately
2 percent each year, the continued replace-
ment of older, less-efficient automobiles
with newer, more-efficient ones yielded a net
decrease in the emission estimates of about
10 percent. The same comparison regarding
transportation sources can be made for the
U.S. NOx emission estimates. An analysis
of the overall trend in the Canadian emission
estimates shows a decrease or flattening
between 1980 to 1992. Canada has also
been developing industrial and transportation
pollution controls equivalent to those in the
United States. The two countries have been
working together to ensure emission inventory
data consistency and coordination in
emission trends analysis.
ATMOSPHERIC MODELLING
In Annex 2 of the Air Quality Agreement,
Canada and the United States agreed to
exchange information on the development
and application of atmospheric models
determining source-receptor relationships
and transboundary transport and describing
the deposition of air pollutants. This section
summarizes results from linear (Lagrangian)
and nonlinear (Eulerian) models and describes
progress in the evaluation of Eulerian models.
These models are used for a number of pur-
poses, including analyses of different emis-
sion scenarios and the resulting change
in air quality and deposition.
Model Application
Previous studies reported the impact of
S02 emissions from a given source region
on deposition in a receptor region (source-
receptor relationship). Since the last Progress
Report, similar studies have been conducted
for nitrogen using a long-range transport
sulphur/nitrogen model and 1980 base-year
data. For example, the Canadian contribution
to nitrogen concentrations and deposition
was found to be greatest at Gander in
Newfoundland (60 to 70 percent) and least
at Algoma at the eastern end of Lake Superior
(7 to 11 percent). Despite the model deficien-
cies and uncertainties, these matrices provide
the first published quantitative estimates of
the relative contributions of Canadian and
U.S. source regions to nitrogen concentra-
tions and deposition at several receptors
in the two countries.
23
-------
Scientists in Canada and the United States
are exchanging information on how to use
atmospheric models to anticipate future
deposition patterns and how to use the
predictions to improve the ability of deposi-
tion monitoring networks to detect pattern
changes. Canadian and U.S. models have
been used to project sulphate deposition
patterns following the implementation of
various phases of both countries' acid rain
control programs (i.e., using the Canadian
Lagrangian Long Range Transport Sulphur
Model and the U.S. Eulerian Regional Acid
Deposition Model [RADM]). The predicted
patterns have been used to test the appro-
priateness of the existing networks and to
recommend changes in network design. As
sulphur emission control programs are being
implemented, deposition monitoring networks
are continuing to fulfil the principal goals of
detecting and quantifying temporal and spa-
tial changes in deposition. The networks are
being modified in accordance with the rec-
ommendations of the modelling studies.
Model Evaluation
The two countries have been cooperating
in model evaluation using information from
the Eulerian Model Evaluation Field Study
(EMEFS). Since the last Progress Report,
Phase 1 of the evaluation of the two advanced
acidic deposition models — ADOM (Acid
Deposition and Oxidants Model) and RADM
— has been completed. This phase is primarily
based on 1988 EMEFS data. Phase 2 will
be based on 1990 EMEFS data as well as
critical data from the 1988 period; it is to be
completed in 1994. Additional cooperative
efforts in the further evaluation and applica-
tion of the advanced models will continue
under the Air Quality Agreement.
A peer review panel has confirmed the ability
of the models to represent (1) total sulphur
loading of the atmosphere; (2) annual sulphur
deposition (although there is some seasonal
bias, with deposition being underestimated in
summer and overestimated in winter); and (3)
total nitrogen loading of the atmosphere. The
reviewers concluded that the models could be
used for developing current estimates as well
as projections of annual deposition of sulphur
and nitrogen.
The reviewers also concluded that, while
both models were adequate for the study of
large-scale and long-distance source-receptor
relationships, their complexity will pose a
limitation. A valuable application would be
for the complex models to serve as a check
on the source-receptor matrices produced by
simpler but much faster Lagrangian methods.
The reviewers agreed that the differences
between the simple and complex models'
estimates of deposition may be on the
order 10 to 15 percent.
MONITORING ACTIVITIES
Coordination of
Monitoring Activities
Regional Dry Deposition Estimates
Dry deposition is an important process by
which acidic air pollutants are deposited to
the Earth's surface. In contrast to wet deposi-
tion, dry deposition is very difficult and costly
to measure and consequently there have •
been fewer direct measurements. Thus, rates
of dry deposition fluxes in Canada and the
United States are usually determined by cal-
culating dry deposition as the product of a
measured air concentration and a modelled
deposition velocity. Deposition velocity is
modelled as a function of surface characteris-
tics and measured meteorological variables
or climatological data.
Air concentration measurements appropriate
for estimating dry deposition are taken at
multiple locations in both countries. In
Canada, the Canadian Air and Precipitation
Monitoring Network (CAPMoN) has been
providing daily concentration data of SO2,
particulate-SO4, nitric acid (HNO3), and partic-
ulate-NOg at 11 sites for up to 14 years. In the
United States, the National Dry Deposition
Network (NDDN) was established in 1987 and
currently reports weekly averaged concentra-
tion data for SO2, particulate-sulphate (SO4),
nitric acid (HN03), particulate-nitrate (N03),
and ammonia (NH3) for 50 sites. A map of air
concentrations of SO2 for 1991 at Canadian
and U.S. sites is shown in Figure 6. Both
networks have observed a gradient in air
concentrations with high values occurring
closest to areas of greatest S02 emissions.
There is very little difference between these
observations and those reported in the previous
Progress Report. These air concentration data,
combined with land/vegetation information
24
-------
Figure 6 Median 1991 S02 Air Concentrations at CAPMoN and NDDN Sites
17.01 -12.47^ F-763
-?•/-<*
• NDDN
• NOAA
A CAPMON
• NDDN and NOAA
-------
and hourly meteorological or climate data,
give an estimate of dry deposition through
an inferential model approach. Although
Canadian and U.S. approaches to estimating
dry deposition are similar, the differences
preclude publishing a composite description
of dry deposition over eastern North America
at this time. To further minimize the differ-
ences, Canadian and U.S. measurement and
modelling techniques are being compared.
To determine if there could be systematic
differences (biases) arising from the use of
different methods of sample collection and
analysis, collocated NDDN and CAPMoN
measurements of air concentrations of various
gases have been carried out. Such differences
could lead to air concentration and deposition
discontinuities across the Canada-U.S. border.
With the exception of S02, where a difference
of 14 percent was noted, measured differences
were found to be small.
In Canada, current investigations are focusing
on the advantages and disadvantages of the
various models that are available to deter-
mine an appropriate and comparable model-
ling framework. In the United States, recent
advances in model design are being applied
to the NDDN measurements. The overall goal
of the work in both countries is to improve
model estimates of dry deposition of all acidi-
fying species by increasing the understanding
of the processes involved in delivering gases
and particles to the Earth's surface.
Estimating Total
Sulphur Deposition
Total deposition is the sum of wet, dry,
and droplet deposition. Work is under way
to develop an effective way to combine esti-
mates of dry deposition with wet deposition
measurements that will provide comprehen-
sive information on regional variations. Also,
efforts are being made to achieve greater cer-
tainty in the characterization of spatial wet
deposition fields of sulphate and nitrate in
Canada and the United States. The current
method employs interpolation between the
sparse measurement sites, using precipitation
depth measurements taken only from the acid
deposition networks rather than the fuller set
of observations provided by national weather
services. It is expected that uncertainties in
the spatial distributions will be decreased by
combining interpolated precipitation chemistry
fields with more detailed observed precipita-
tion amount fields, thereby producing more-
highly resolved wet deposition fields.
Significant contributions to total deposition
can come from fog and cloud water droplet
deposition in certain geographical locations.
For example, mountain peaks in eastern North
America are subject to cloud deposition that
may be equivalent to or greater than deposi-
tion from precipitation. The United States
collected cloud water and calculated cloud
water deposition as part of the National Acid
Precipitation Assessment Program (NAPAP)
from 1986 through 1989. Canada also mea-
sured cloud water during this time period
as part of the federal/provincial Acid Rain
Research and Monitoring Program. In the
United States, the Clean Air Status and
Trends Network (CASTNET) is reinitiating
sampling at some of the previous sites and
installing new sites. In Canada, fog chemistry
and sulphate deposition are currently being
measured in coastal areas in the Atlantic
Provinces in order to more accurately
describe total sulphate deposition. The
work indicates that on average the sulphate
deposition from fog is almost equal to that
from rain and snow in the New Brunswick
Fundy Coast region.
Findings of Air Pollutant
Monitoring Activities
Deposition Networks
The National Atmospheric Deposition
Program/National Trends Network
(NADP/NTN) is the largest wet deposition
network in the United States, operating
on a weekly measurement protocol with
approximately 200 sites, some with data
records dating from the early 1980s.
CASTNET operates wet deposition sites to
supplement the NADP/NTN in areas that do
not have monitoring sites, such as mountain
and coastal regions. The National Oceanic
and Atmospheric Administration (NOAA)
recently established a daily wet deposition
network, the Atmospheric Integrated Research
Monitoring Network (AIRMoN). The daily
sampling schedule will provide data for
addressing the localized effects of emission
controls to be used in source/receptor model-
ling. Wet deposition data from NADP/NTN,
CASTNET, and the Canadian CAPMoN and
26
-------
provincial networks have been combined.
The spatial distributions of wet sulphate and
nitrate deposition in 1988,1989,1990, and
1991 are shown in Figures 7 to 14. Comparing
1988 data with data from 1991 shows in both
years an almost total lack of areas receiving
more than 30 kg wet sulphate/ha/yr. In con-
trast, the intervening years (1989 and 1990)
show considerable larger areas as having
received more than 30 kg/ha/yr, as was the
case for the years prior to 1988. A direct
comparison of 1988 with 1991 would not
have given a realistic assessment of what
had actually occurred since the last Progress
Report. In all four years, the highest deposition
was seen in the states of Ohio, Pennsylvania,
and West Virginia (Figures 11 to 14). The high-
est nitrate deposition was seen in southern
Canada in 1988 and in the following years
in areas adjacent to the Great Lakes.
Deposition Trends
Figures 15 and 16 show the variability from
1980 to 1991 in the precipitation weighted
mean concentration of sulphate and nitrate
in Canada and the United States. Deposition
is a reflection of both the amount of sulphate
in the rainfall (concentration) and the amount
of rain in any given area. Because of the
greater variability in rain from year to year,
trends can be more easily detected in the
concentration of sulphate rather than in
deposition. A significant downward trend
was seen in sulphate concentration in rain at
26 to 33 U.S. NADP/NTN sites over the 1980-
1991 period. A Canadian study showed that
sulphate concentrations from both Canadian
and U.S. sites showed significant long-term
trends over the same period with reductions
in concentrations being seen early in the
decade and with a tendency to level off later
in the decade. In contrast, while significant
trends were seen for changes in the nitrate
concentrations in precipitation, there was
no dominant trend in terms of increase
or decline.
Between 1980 and 1985, the total S02 emis-
sions in eastern North America decreased by
about 15 percent, after which they remained
approximately constant. NOx emissions, on
the other hand, showed no strong downward
trend and exhibited only slight annual varia-
tions (i.e., of less than 5 percent) around the
mean from 1980 through 1991. In general,
changes in S02 emissions are reflected in
changes in sulphate concentrations in precipi-
tation. Nevertheless, the ecological response
is often a reflection of both the amount and
the concentration (deposition) and trends
in deposition needed to be investigated. For
the period studied, changes in deposition are
seen to reflect the changing emission patterns.
A statistically significant relationship exists
between the SO2 emissions over eastern
Canada and United States and the sulphate
concentration trends averaged over all sites
in the same area. When sulphate wet deposi-
tion is integrated across all of eastern North
America and compared with the integrated
SO2 emissions over the same area, a close
correlation exists between sulphate deposition
and emissions initially showing both emissions
and deposition declining (Figure 17 on page
32). However, due to the uncertainty in the
data, trends in the latter half of the decade
are not obvious. The normalized integrated
nitrate deposition showed no upward or
downward trend over the decade consis-
tent with the normalized NOx emissions.
Continued monitoring and analysis is needed
to quantify the link between reduced S02
emissions and subsequent reduced wet
sulphate deposition.
EFFECTS RESEARCH
AND MONITORING
Aquatic Ecosystems Trends
Reduction in North American SO2 emissions
is expected to reduce acidic deposition and
result in beneficial changes in the chemistry
and biology of lakes and streams that have
been adversely impacted by acidic deposi-
tion. Some emission reductions have
occurred since the 1980s. Assessment of
chemical trends observed in surface waters
during this period provides a qualitative
indication of the response complexity,
a verification of whether ecosystems do
in fact respond positively, and a baseline
for evaluating future changes.
Canada
The 1983-1991 chemical records from 111
lakes or streams in southeastern Canada
were evaluated to identify increasing or
decreasing trends that were statistically
significant at a 95 percent confidence level.
27
-------
Figure 7 1988 Wet SO Deposition
Sea Salt Corrected (kg/ha/yr)
SON
115W
110W
10SW
100W
60N
55N
SON
45N
40N
35N
SON
25N
95W 90W 85W ' SOW
Figure 8 1989 Wet SO Deposition
Sea Salt Corrected (kg/ha/yr)
60N
115W
HOW
25N
Figure 9 1990 Wet S04 Deposition
Sea Salt Corrected (kg/ha/yr)
60N
115W
110W
105W
100W
25N
95W 90W 85W SOW 75W 70W
28
-------
Figure 11 1988 Wet N03 Deposition
(kg/ha/yr)
Figure 12 1989 Wet NO Deposition
(kg/ha/yr)
60N
60N
1t5W
110W
105W
100W
-*>
55N
SON
45N
40N
35N
30N
25N
86W SOW 85W SOW 75W 70W 6SW 60W
Figure 13 1990 Wet NO Deposition
(kg/ha/yr)
r^w
Figure 14 1991 Wet NO Deposition
(kg/ha/yr)
60N
115W
now
100W
60N
5SN
SON
45N
40N
3SN
30N
25N
95W 90W 85W SOW 75W 70W 65W SOW
29
-------
Figure 15 Precipitation Weighted Mean SO; Concentration, Sea Salt Corrected (mg/l)
81 828384858687888990 31
Considering all 111 sites together, 31 percent
(mostly in Nova Scotia and Newfoundland, a
few in Ontario) are recovering. These sites
show an increasing pH and/or acid neutraliz-
ing capacity (ANC) trends (regardless of the
sulphate trend). Lakes within the Sudbury
region of Ontario have also been recovering
throughout the 1980s in response to emis-
sion reductions from local sources. If these
lakes had been included in the statistical
analysis, a greater proportion of Ontario's
waters would have been classified in the
recovering group. Forty-one percent of the
sites showed no trend in pH or ANC and no
change in sulphate concentration (i.e., from
1983 to 1991, their acidification status was
stable). Thirteen percent (mostly in Nova
Scotia and Newfoundland) exhibited stable
pH and/or ANC but significantly increasing
sulphate. If sulphate continues to increase
at these sites and the present compensatory
mechanisms fail, these waters might eventu-
ally acidify. Fifteen percent of the waters
(mostly in Ontario and Quebec) are continuing
to acidify (declining pH and/or ANC) despite
having stable or declining sulphate levels.
Some of the water chemistry trends recog-
nized by this analysis differ from those identi-
fied by earlier studies that used a different
timeframe. In southwestern New Brunswick,
18 percent of 40 headwater lakes sampled in
1993 had negative ANC compared with 3 per-
cent with negative ANC for the same lakes in
1986. This is to be expected, given the short
monitoring period for which records are
presently available for evaluation (i.e., short
relative to the response times of many catch-
ment processes). Moreover, the results show
30
-------
Figure 16 Precipitation Weighted Mean N03 Concentration (mg/l)
that the regional responses of waters to
reductions in SO2 emissions are not straight-
forward. Only high-quality, long-term moni-
toring records will reliably quantify the chem-
ical and biological responses to SO2 control.
United States
About 80 low-ANC lakes and streams have
been monitored in the northeastern and upper
midwestern United States since the early
1980s as part of EPA's Long-Term Monitoring
Program. Trends in surface water chemistry
were calculated for each site through 1989.
Surface waters monitored during the 1980s
are generally representative of low ANC
systems in these regions, but they were
not selected as a statistically representative
sample of lakes and streams. Regional trends
monitoring began in 1991 in the Northeast
and in 1993 in the Mid-Appalachians to evalu-
ate changes in regional surface water chem-
istry in response to the emission reductions
mandated by the 1990 CAA Amendments.
Data from current regional monitoring
studies will be available for future reports.
Sulphate concentrations declined in 50 of 53
waters monitored in the northeastern United
States. Thirty-four sites (64 percent) had a sta-
tistically significant decrease in sulphate (at a
90 percent level of confidence), whereas none
had a significant increase in sulphate. Given
that sulphate deposition declined in the late
1970s and early 1980s, but has remained rela-
tively constant since then, these results sug-
gest a time lag between decreased deposition
and decreases in surface water sulphate. Soils
-------
Figure 17
that have historically become saturated with
sulphate, due to high sulphate deposition,
are now gradually losing sulphate.
In contrast, nitrate concentrations, increased
during the period of record in all 24 of the
lakes and streams monitored in two Northeast
subregions: the Adirondack and Catskill
Mountains of New York. Fourteen of these
waters (58 percent) had a statistically signifi-
cant increase in nitrate, while none had a sig-
nificant decrease. Similar increases in nitrate
did not occur in lakes in Vermont and Maine.
Increases in nitrate in Adirondack and Catskill
waters occurred even though no pattern is evi-
dent in trends in nitrate deposition (Figure 18).
Current theories suggest that watersheds in
the Adirondacks and Catskills may be moving
toward nitrogen saturation. This is due
to historically high nitrate deposition and
a natural predisposition to nitrogen satura-
tion (because of high soil nitrogen content
and the presence of mature forests).
Normalized Annual S02 Emissions
and Sulphate Wet Deposition, Sea Salt
Corrected, Over Eastern North America
1.05-
1.00-
0.95
0.90
0.85
0.80
0.75
0.70-
•
A
O
A
0
o
0 A
A 00
IB 0 0
O
0 A
A
A A
A
9 80 81 82 83 84 85 86 87 88 89 90 91 92
a SO2 Emissions
A SO4 Wet Deposition,
Sea Salt Corrected
Time series showing the annual emissions and annual
deposition over eastern North America from 1980 to
1991. All values are normalized to 1980 as unity.
Trends in ANC, pH, and base cations in
Northeast surface waters were not nearly as
consistent as those for sulphate and nitrate;
both increases and decreases occurred with
no strong regional pattern. In the Adirondacks,
13 of 16 lakes (81 percent) had decreased ANC,
but only 5 (31 percent) had a statistically sig-
nificant decrease in ANC. In contrast, in New
York's Catskills and in Maine and Vermont,
28 of 37 waters (76 percent) increased in
ANC; nine sites (24 percent) had a significant
increase in ANC. ANC, pH, and base cations
are probably affected by several interacting
factors, including decreased sulphate deposi-
tion and increased nitrate leaching in some
areas (which may offset the benefits of declin-
ing sulphate), as well as shifts in base cation
deposition, aluminum, and organic chemistry.
Long-term monitoring data are also available
for 28 lakes in the Upper Midwest. There is
some indication of a regional decrease in
surface water sulphate during the period
of record (16 lakes have decreased, 12 have
increased, but all 8 of the statistically signifi-
cant trends were decreases). Lakes had no
measurable changes in nitrate, and there
was no consistent pattern in pH, ANC, or base
cation trends. Many of the lakes monitored
in the Upper Midwest are seepage lakes
(with no tributary streams), which receive
water directly from precipitation and ground
water. Such lakes tend to have long water-
turnover times, and thus longer response
times. In addition, drought conditions in much
of the Upper Midwest during the 1980s com-
plicated interpretation of lake responses
to changes in sulphate deposition and
aluminum and organic chemistry.
Biological Responses
Many studies have demonstrated that acidifi-
cation can and has adversely affected aquatic
biota. For example, entire lakes were experi-
mentally acidified — two in the Experimental
Lakes Area of Ontario and one in northern
Wisconsin —to increase understanding of
both the direct and indirect effects of acidifica-
tion on aquatic communities. Changes in lake
biology occurred at each pH level over a
pH range of 6.1 to 4.7. Acid-sensitive species
disappeared and were replaced by fewer acid-
tolerant species, resulting in reduced species
richness and simplification of the lake's food
web. One of the most visible acidification
32
-------
effects was the growth of thick mats of
filamentous benthic algae, which covered the
shallow, littoral zone beginning when the pH
dropped to 5.6. Acidification also caused fish
reproductive failures and population declines,
primarily as a result of increased mortality
of young fish. Analyses of monitoring and
survey data have confirmed fish population
losses due to acidification from some surface
waters in many parts of northeastern North
America. For example, in the Adirondack
region of New York, 16 to 19 percent of the
lakes with adequate historical data appear
to have lost one or more fish species as a
result of acidification. The estimated number
of lakes in Ontario that have either lost their
sport fish populations or have residual nonre-
producing populations is 228: lake trout, 119;
brook trout, 43; smallmouth bass, 52; and
walleye, 14. One third of the available Atlantic
salmon habitat in Nova Scotia has been lost
since 1950 because of acidification. This is
a loss to the salmon fisheries of about 9,000
to 14,000 fish per year and is almost equal
to the current annual catch.
Information on the recovery of biological
communities following improvements in
water quality has also become available in
recent years. After experimental acidification,
the pH in one lake was allowed to gradually
increase from 5.0 in 1983 to 5.8 in 1988.
Several biotic components recovered rapidly.
The extensive mats of filamentous algae,
which first appeared at pH 5.6 during acidifi-
cation, disappeared at pH 5.8. Fish resumed
reproduction at pHs similar to those at which
reproduction ceased during acidification. Many
species of insects and crustaceans that had
disappeared during acidification returned.
Trends data for lakes around Sudbury,
Ontario, also provide evidence of biological
recovery. Reductions in emissions of SO2
and trace metals from the Sudbury smelters
during the 1970s and early 1980s have resulted
in substantial improvements in water quality in
many surrounding lakes. As lake pH increased
and concentrations of toxic metals declined,
zooplankton and phytoplankton species
richness increased and some acid-sensitive
species of insects and crustaceans, such as
Epischura lacustris, reappeared. Organisms
with low dispersal activity, however, such as
the amphipod Hyalella azteca, have not yet
recolonized these lakes even though pH levels
have met or exceeded those required for natural
populations for several years. Likewise, natural
recolonization by fish is likely to be limited
and slow, except where lakes are connected
directly to unaffected lakes or other areas of
refuge. Stocking, however, re-established a
naturally reproducing population of brook
trout in Joe Lake; brook trout had disappeared
from Joe Lake in the late 1950s to early 1960s.
Whitepine and Nelson lakes near Sudbury
supported remnant populations of large, old
lake trout, which resumed reproduction when
pH increased to 5.6. Thus, results from these
studies suggest that many biological popula-
tions will recover or can be re-established
relatively rapidly (in less than a decade) when
acidification is reversed.
Historical Lake Acidification
in North America
Evaluation of the fossil remains of aquatic
organisms buried in lake sediments can pro-
vide indirect evidence of past lake chemistry
Figure 18 Normalized Annual NOx Emissions
and Nitrate Wet Deposition Over
Eastern North America
1,10
1.05
i.oo
0.95
0.90
0.85
0.80
0.75
A
D
79 80 81 82 83 84 85 86 87 88 89 90 91 92
i«' • -r r-'nj "»v" •• ^^' ' -•*••-• j LEjpii ~— .!!•
i • • m,;,wie series showing the annual emissions and annual
| a NOx Emissions Eptftfen'over eastern North America from T980 to
N 03 Wet Deposition gtsxfa, tffi values are normalized to 1980 as unity.
-------
since certain species tolerate only a limited
range of conditions. Recent studies show that
lakes with low base cations and ANC are the
most likely to have experienced acidification
due to acidic deposition, whereas lakes with
historically higher pH levels have exhibited
little change or even become more alkaline.
For example, in a comprehensive study of
this type conducted in 1991, 80 percent of
a target population of Adirondack lakes with
present-day pH < 5.2 have undergone large
declines in pH and ANC and concomitant
increases in aluminum, but only 30 to 45
percent of lakes with current pH between 5.2
and 6.0 were so affected. Similarly, all lakes
in the Sudbury area of central Ontario that
presently have pH < 6.0 show evidence of
extensive past acidification, whereas those
with current pH between 6.0 and 7.0 have
changed little from their historical pH levels.
Quebec Lake Survey
Between 1986 and 1990, the chemistry of
1,253 Quebec lakes within the 10 to 2,000
hectare(ha) size class and south of 51°N
was measured. At the same time, fish
surveys were completed on 253 lakes from
the 20 to 200 ha size class. The lakes chosen
for the chemical sampling were statistically
representative of the lake population within
the size class, with the lakes covered by the
fish survey being a subset.
Results of the chemical survey show that
19 percent of the lakes (or 6,150 of the total
population of 31,800 lakes in the size class)
have pH < 5.5, and 52 percent (16,500 lakes)
have pH < 6.0. These low pH lakes are located
mostly south and east of Noranda, north
of Quebec City, and in northeastern Quebec.
Sulphuric acid (H2S04) introduced through
the atmosphere is mainly responsible for
the acidity of lakes in southwestern Quebec,
while the acidity of northeastern lakes is
due mainly to natural organic acids. Hence,
chemical recovery of acidic lakes following
emission reductions will occur primarily
in southwestern Quebec.
Fish surveys conducted in the southwestern
regions where H2SO4 is of greatest impor-
tance showed that the number of species
present decreases with decreasing pH: from
100 percent of all 32 identified species at
pH = 6.0, to 72 percent at pH = 5.5, to 28 per-
cent at pH = 5.0, and to 0 percent at pH = 4.5.
At pH < 5.0, fish reproduction is limited
and younger age classes are often absent.
Implementation of control measures at the
Noranda smelter in 1989 has resulted in
a decrease of more than 60 percent in S02
emissions compared with 1980. Compared
with 1982 levels, 1991 sulphate concentrations
in lakes near the smelter have decreased by
>50 percent, and lakes >200 km away have
decreased 0 to 20 percent. There was no
change in ANC during this time period,
however. Although the decrease in sulphate
is encouraging, findings indicated that repeti-
tion of the lake survey in the mid-1990s will
be needed to verify an attendant improve-
ment in the acidity status of these lakes.
Episodic Response Project
Aquatic ecosystems can be adversely affect-
ed not only by chronic acidification, but also
by short-term (episodic) decreases in pH that
occur during snowmelt and rainstorms. EPA
conducted an Episodic Response Project (ERP)
in 1993 that studied the effects of episodic
acidification on fish in 13 streams in the
Adirondack and Catskill Mountains in New
York and the Northern Appalachian Plateau
in Pennsylvania.
ERP results clearly demonstrate that episodic
acidification can have long-term adverse
effects on fish populations. Streams with
suitable chemistry during low flow, but low
pH and high aluminum levels during high
flow, had substantially lower numbers and
biomass (weight) of brook trout than were
found in non-acidic streams. Streams having
acidic episodes showed significant mortality
of fish. Some free-living brook trout avoided
exposure to stressful chemical conditions
during episodes by moving downstream
or into areas with higher pH and lower alu-
minum. This movement offish only partially
mitigated the adverse effects of episodic acidi-
fication, however, and was not sufficient to
sustain fish biomass at levels that would be
expected in the absence of acidic episodes.
These findings indicate that stream assess-
ments based solely on chemical measure-
ments during low flow conditions will not
accurately predict the status of fish com-
munities in small streams.
Atmospheric deposition of sulphate and
nitrate contributed significantly to the
34
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occurrence of acidic episodes, with low
pH and high aluminum levels, in the ERP
streams. In addition, naturally occurring
organic acid from decomposing vegetation
also commonly contributed to episodic pH
depressions. Sulphate and nitrate pulses,
however, augment these natural processes to
create episodes with lower pH and higher alu-
minum concentrations than would occur from
natural processes alone. Yet even in streams
with high enough background or base flow
concentrations of sulphate and nitrate to cause
natural pH depression, episodic atmospheric
deposition still causes a significant additional
depression of the pH. This effect is noted
even though the apparent stream concentra-
tions of sulphate and nitrate remain relatively
constant during the episode.
Nitrogen Deposition
and Water Acidification
While S02 emissions have declined through-
out North America, NOx emissions have
remained fairly constant. Existing levels
(or increases) of nitrogen deposition over
the long term could eventually undermine
the ecological benefits derived from the
S02 control programs.
The most important technical question
concerning nitrogen-based ecosystem acidifi-
cation is the mobility of nitrogen. When nitro-
gen contributes to acidification, the nitrogen
deposition in excess of that immobilized for
the nutrition of terrestrial and aquatic biomass
is leached into ground and surface waters as
nitrate. This situation implies a change in the
"normal" functioning of the nitrogen cycle
from a virtually closed internal cycle to an
essentially open cycle where excess nitrogen
is leached — a state commonly referred to
as nitrogen saturation. The development of
nitrogen saturation involves a complex inter-
action of processes in a watershed's nitrogen
cycle, not just an increase in atmospheric
input. Increasing or chronically high nitrate
concentrations in runoff waters or alteration
of characteristic seasonal patterns indicate
that a watershed may be at or progressing
toward nitrogen saturation and nitrogen-based
surface water acidification. In addition to con-
cerns about acidification, there are concerns
that high nitrate concentrations may possibly
contribute to eutrophication (increase in input
of nutrients leading to a growth in algae) in
estuarine areas and near coastal waters. High
nitrate concentrations alone are believed
unlikely to cause freshwater eutrophication.
Lake survey data from eastern Canada and
data from long-term monitoring projects
in the 1980s and 1990s in the United States
confirm that there are watersheds in both
countries that are likely retaining less nitro-
gen than they did in the past. Nitrate can be
a major contributor to episodic acidification,
particularly during spring snowmelt when
biological uptake of nitrogen is minimal.
Increasing trends in nitrate have been
observed in some lakes and streams in the
Adirondack and Catskill Mountains of New
York, the Mid-Appalachian region, Ontario,
and Quebec. These locations also receive
some of the highest levels of nitrogen depo-
sition. Although the link between saturation
and deposition must still be considered
circumstantial, preliminary model analyses
suggest that high levels of nitrogen deposi-
tion can reduce the time required for water-
sheds to reach nitrogen saturation. Future
aquatic research and monitoring would be
necessary to better quantify which ecosys-
tems are becoming saturated and why, and
to determine deposition levels at which
nitrogen saturation occurs.
Forest/Soils Studies
Research has shown that acidic deposition
directly affects tree foliage and soil chemistry
and that it has contributed to the decline of
high-elevation spruce forests in the eastern
35
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United States. Acidic deposition is suspected
as a contributing factor in the increased
dieback and decline in birch forests in eastern
Canada. Monitoring of forests, research on
ameliorating symptoms, and studies on forest
productivity continue in both countries.
Forest health in both countries has been
assessed by comparing the crown condition,
mortality, and growth rates using various
monitoring systems. Methods and results
varied. All systems showed that changes
in crown condition and mortality reflected
the combined effects of insects, diseases, and
air pollution. Growth rates in one monitoring
system studied were found to correlate with
levels of pollutant deposition on soils where
nutrients were limited.
A number of Canadian and U.S. networks
have been established to monitor forest health
by assessing damage to forests caused by
acid deposition. Results to date indicate that
there is no large scale decline in the health of
Canadian and U.S. forests that can be directly
attributed to acidic deposition.
Joint Studies —
North American Maple Project
This monitoring program was established
in 1988 by Canada and the United States in
response to reports of widespread decline
in sugar maples. The program measures the
condition of tree crowns in managed (sugar
bush) and unmanaged (non-sugar bush)
stands. Results from 1988 to 1992 show that
over 90 percent of the trees sampled were
healthy, and mortality rates were normal.
The condition of sugar maples in sugar bush-
es was not significantly different from that
of sugar maples in unmanaged stands, nor
was tree condition affected by different zones
of deposition. Changes in tree condition were
caused by natural factors, specifically drought
and insects. The monitoring system tracked
these events and the data show that trees
recovered from these stresses after two to
three years. Other Canadian and U.S. net-
works designed to monitor forest health
have looked for damage to forests caused
by acid deposition.
Canada — National Networks
In 1984, Forestry Canada's Acid Rain National
Early Warning System (ARNEWS) was estab-
lished to monitor forest health. ARNEWS is
designed to detect forest damage by assess-
ing a common set of measurements from
permanent sample plots, supplemented
by additional surveys.
U.S. State Networks —
Forest Health Monitoring
The U.S. Forest Health Monitoring (FHM)
Program is a cooperative effort between
federal and state resource agencies to collect,
analyze, and report on the health of all forested
lands in the United States. The program has
three objectives: (1) detection monitoring; (2)
evaluation monitoring; and (3) intensive site
ecosystem monitoring. Over 1,000 plots in 14
states have been studied and results through
1992 do not show any extensive unexplained
forest or tree decline. The system is sensitive
enough to have detected the effects of known
pests, such as American beech bark disease
and hemlock looper.
36
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U.S.-State Networks —
Hardwood Tree Health Survey
The State of Vermont first conducted a
statewide survey of hardwood tree health in
1986, reporting that 22 percent of the upper
canopy hardwood trees had >10 percent
crown dieback, and 2.9 percent of the standing
hardwood trees were dead. By 1991, the per-
cent of upper canopy hardwood trees with
>10 percent dieback had declined to 14 per-
cent. Nearly 25 percent of the trees that had
>10 percent dieback in 1986 were dead by
1991 (5.5 percent of the standing hardwood
trees). The study concluded that the health
of surviving trees had improved from 1986
to 1991 because of decreased insect popula-
tions and increased precipitation since 1986.
Responses to
Air Pollution Studies
Canada — White Birch Decline
Severe foliage browning and premature
leaf-fall in southeastern New Brunswick in the
mid-1980s have resulted in serious deteriora-
tion and mortality of white birch. The damage
was not caused by insects or diseases, but
occurred in areas with a high frequency of
summer fog that has been measured below
pH 3.0. The sensitivity of birch was confirmed
by clonal transplant tests. Since 1989, there
has been a reduction in foliage browning and
a regreening of surviving trees. The improve-
ment in the condition of surviving trees since
1989 is correlated with a reduction in the
frequency of fog, indicating a cause-and-effect
relationship between damage and acid fog.
A similar condition may be developing
in the Wawa area of Ontario.
Canada — Ontario Maple
Observations of maple decline have been
monitored by health surveys focusing on
visual symptoms. In addition, the Ontario
Ministry of the Environment and Energy has
also examined the growth rates of maples
throughout the province. Dendrochronological
(tree ring growth) data have showed that sus-
tained reduction in growth has occurred
concurrently with increasing pollution levels.
Growth reductions were in proportion to the
wet sulphate and nitrate deposition being
received by each study site. Reductions of
forest health were greater on soils with poor
buffering capacity. Tree growth, however,
was also affected by climatic stresses and
outbreaks of defoliating pests.
United States —
Red Spruce Decline
Unexplained increases in mortality of high-
elevation red spruce in the eastern United
States were reported in the early 1980s. At
the time, examination of the climate, pest
history, and stand dynamics did not explain
the change in spruce condition. Research
begun in the later part of the 1980s has, to
date, indicated that winter injury to spruce
foliage is clearly associated with growth dam-
age and mortality to trees. Both laboratory and
field evidence indicated that increased levels
of acidic deposition associated with cloud
water increased the susceptibility of red
spruce foliage to winter injury. Aluminum
interference with plant nutrient uptake and
increased levels of cation leaching from nutri-
ent-poor ecosystems were documented in
some ecosystems. The level of acidic deposi-
tion in these ecosystems is consistent with
the level required to cause damage.
Canada — Critical
Loads for Forest Soils
Canada is developing critical loads for forests
using a dynamic model to predict chemical
and physical biomass (weight) changes in
upland forests as a result of acid sulphate/
nitrate loading. The term critical load refers
to a quantitative estimate of the maximum
exposure to a pollutant that a soil can sustain
without significant damage. The model fore-
casts long-term reductions in site productivity
at current levels of pollution. The model will
be used to estimate critical loadings for
Canadian forests. Numerical estimates are
expected to be available for public discussion
by the end of 1995.
Canada — Remediation Studies
One hypothesis concerning the reason for
forest decline is that tree nutrition is impaired
by acid deposition, which leaches base cations,
principally potassium, calcium, and magne-
sium. Consequently, during the period 1988 to
1991, fertilization treatments for restoration of
37
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soil cation levels were applied to several sites
in Ontario and Quebec with declining forests.
Generally, declining trees showed a greater
response than healthy trees, but the response
to the fertilizer treatments varied among sites
and among declining and healthy trees. This
indicates that the causes of decline and the
response to fertilizers were specific to indi-
vidual sites. Thus, there would appear to be
little benefit in fertilizing extensive areas to
avoid damage from air pollutants.
Canada-United States —
Effects of Nitrogen Deposition
Continued deposition of nitrogen will increase
the amount of nitrogen in forest ecosystems
and, depending on the nature of the soil, will
increase the capacity for nitrification and the
movement of nitrogen to surface water.
Vegetation growth can be expected to increase
where nitrogen is limiting and where deposi-
tion does not interfere with nutrient uptake
and/or introduce additional stresses. Continued
nitrogen deposition will affect mycorrhizae
(fungi), insects, pathogens, and wildlife.
Research on nutrient cycling is continuing in
both countries to assess long-term impacts
of increased nitrogen deposition on soils
and vegetation.
Visibility
Annex 1, Section 4 of the Canada-United
States Agreement on Air Quality recognizes
that the prevention of significant air quality
deterioration and the protection of visibility
are important to both countries. This annex
requires the United States to apply Part C
of Title 1 of the U.S. Clean Air Act to sources
that would cause significant transboundary
air pollution. The annex requires Canada,
by January 1995, to develop and implement
means of preventing significant air quality
deterioration and protecting visibility compa-
rable to those called for in the U.S. legisla-
tion. Since the last Progress Report, several
areas of research have been initiated in
Canada to meet this obligation.
Canadian Airport Visibility Data
A technique has been developed in Canada
to extend the range for capturing airport visi-
bility data. The new approach enables the
development of visibility estimates at dis-
tances greater than 24 km (15 miles). Maps of
the visibility across Canada by season and by
year give a historical record of median visi-
bility in Canada since 1951. This will serve as
the baseline against which visibility changes
in the future will be determined. Efforts are
under way to merge the historical visibility
data sets in Canada and the United States.
Visibility Reduction Testing
Environment Canada has been testing tech-
niques by which visibility reduction can be
linked to the aerosol types that scatter and
absorb light. During the 1992 Egbert Aerosol
Study, measurements were made of particle
size. These in situ measurements were made
at the same time and place as light scattering
measurements. The results are being used
to determine the amount of particle growth
attributable to humidity, aerosol scattering
and absorption properties, and a radiation
balance for the scattering process.
38
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Monitoring Aerosols
In addition to the above studies, routine
sampling of visibility-reducing aerosols
was initiated in Glacier/Waterton Lakes
International Park by Canada and the United
States. One sampling site is now operating
on the Canadian side at Waterton, Alberta,
and one on the United States side in Glacier
National Park.
In British Columbia, a significant effort to
understand visibility reduction in the lower
Fraser Valley (near Vancouver, B.C.) is under
way. The Pacific '93 field experiment was
expanded to include aerosol movement
in this region. In addition, the Province of
British Columbia, in cooperation with the
regional offices of Environment Canada and
the University of British Columbia, are ana-
lyzing data from 10 Interagency Monitoring
of Protected Visual Environments (IMPROVE)
sampling stations located in the lower Fraser
Valley. While the intensive phase of this mea-
surement program lasted only for the summer
of 1993, an ongoing program of monitoring
in the valley involving in situ and optical
sampling will be carried on in the future.
Modelling Visibility Changes
In the past, simple sulphate dispersion and
transformation models were used to estimate
ambient sulphate concentrations that influ-
ence visibility. Water vapour, however, also
has been found to contribute significantly
to light extinction. Thus, computations of
visibility degradation need to consider the
availability of water vapour simultaneously
with the amount of sulphate. More complex
models have been developed to produce
new estimates of visibility degradation
attributable to sulphate aerosols in Canada
and the eastern United States. These new
models combine relative humidity predic-
tions from meteorological models with data
from the chemistry and transport models to
more accurately predict the amount of light
extinction (a measure of visibility reduction).
U.S. estimates of the current visibility degrada-
tion in the East (using a perceptible measure
of degradation, termed deciview) and future
visibility degradation, assuming full implemen-
tation of Canadian and U.S. control programs,
have been calculated. This assessment indicat-
ed that a noticeable improvement in visibility
should occur across the eastern United States
(Figure 19) for the 1985 base year, with most
of the change occurring in the warm seasons.
Materials
While joint effects research is not currently
being conducted concerning the degradation
of materials due to acid rain, both countries
participate in a United Nations-ECE
Cooperative Programme entitled "Effects
on Materials Including Historic and Cultural
Monuments." The following presents an
overview of the main findings after four years
of an exposure program that started in 1987.
As expected, for all materials exposed, great
differences in the corrosion rates have been
measured, and the observed degradation is
more severe at polluted sites than at rural
sites with background pollution. For some
materials, like carbon, steel, or nickel, the
effects of pollutants are obvious after the first
year; for other materials like copper or paints,
the effects appear only after four years. For
most materials, SO2 has the strongest corro-
sive effect. Wet deposition expressed as rain
acidity or conductivity has a corrosive effect
on certain materials, which, in general, is less
severe than the effect of dry deposition.
The dominant effect of S02 is evident for
zinc, which is commonly used to coat steel to
reduce corrosion. Sheltered and unsheltered
copper (e.g., shed roofs, decorative items)
also have a high corrosion rate during the
first year at rural sites. At polluted sites,
corrosion increases after the first year due
to the formation of a rough and porous layer
that accelerates the corrosion. Sheltered and
unsheltered cast bronze (commonly used
for statues) are less sensitive to humidity
than copper.
The analysis performed so far has shown
that S02 significantly contributes to the
degradation of unsheltered sandstone and
limestone materials, commonly used in build-
ings and monuments. The damaging effects
of acid rain on wood panels with alkyd paint
and those panels with primer and acrylate
paint are not yet well understood.
Materials (e.g., nickel, copper, and tin) react
differently to S02. SO2 appears to corrode
nickel extensively. While the evaluation of
copper and tin is not yet completed, it appears
-------
Figure 19 MODELLED IMPROVEMENT IN VISIBILITY FOR THE AVERAGE DAY,
1985-2010 (Improvement is expressed in terms of deciviews)
that S02 does not have the same strong cor-
rosive effect on tin as it does on many other
materials. The amount of copper corrosion
seems to be related to the conductivity (e.g.,
higher S02 concentration) of rain.
These results, obtained for plain flat samples,
show clearly that pollutants, particularly SO2,
enhance the degradation of building materi-
als exposed to the atmosphere. In northern
climates, materials already incur heavy
degradation due to, for instance, extreme
temperatures, many freeze-thaw cycles in
winter, and considerable humidity in sum-
mer. The further degradation causes evident
damage in cities like Montreal, where even
newer bronze statues have evidence of the
typical stages of degradation (e.g., streaked
brown, black, blue-green surfaces resulting
from the combined action of acid deposition,
de-icing salts, corrosive dust). Older lime-
stone buildings are either washed by acid
rain and lose their details or they retain
most of the deposited pollutants in protected
areas and then form a crust of gypsum that
forms scales and then flakes off the surfaces
Some recently constructed metallic structure
embedded in cement have corroded to the
point of splitting the concrete.
As confirmed by the results of the ECE
Cooperative Programme, even at low deposi
tion loads all materials are subject to degrada-
tion due to the pollutants. Materials in Canada
might be more susceptible to pollutant degra-
dation because the complex interaction of
40
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pollutants with harsh climactic elements
causes faster degradation than in locations
with more favourable climates but identical
pollution levels.
Human Health
The major new finding since the issuance
of the 1992 Progress Report is that long-term
ambient exposures to acid aerosols have
been linked to a decrease in lung function
in children. In addition, significant progress
has been made on methods to measure
acid aerosols and on elucidating possible
mechanisms involved in health effects. New
research initiatives on the effects of ozone-
acid mixtures have uncovered complex rela-
tionships suggestive of a possible synergism.
Preliminary results of a five-year study of 24
North American cities, designed specifically
to determine the health risk posed by long-
term exposure to ambient acidic aerosols,
have recently been published. The study
included administering a questionnaire and
lung function tests to more than 10,000 chil-
dren between the ages of 8 and 12. In each
community, acid aerosol monitoring was
performed for one year. The results of the
study indicate a strong statistical association
between decreased lung function and long-
term exposure to ambient acidic aerosols.
The annual mean strong acidity in cities
ranged from 0.5 to 52 nanomoles/m3.
Previous studies have suggested possible
adverse health effects due to long-term expo-
sures of airborne acidity, but they had not
measured ambient acidity directly. The inde-
pendent effects of ozone were also assessed,
and they were found to be small. These data
provide further evidence that airborne particu-
late matter, specifically acidic particles, have
a detrimental effect on normal lung function,
growth, and development.
Human clinical studies have examined the
short-term effects of acidic aerosol exposures
and have generally focused on asthmatics
as a sensitive population. These studies sug-
gest that asthmatics may be more sensitive
to short-term high-acid aerosol exposures.
Further work is in progress to determine
the extent of this association.
Although the effects of H2SO4 on clearance
of particulates from the lung has been recog-
nized, new studies in animals have expanded
the knowledge base by showing that H2S04
inhibits the ability of lung defence cells to kill
bacteria; a significant problem in people with
chronic bronchitis is lung infection. Earlier
animal studies gave rise to a hypothesis that
acidic aerosols may cause chronic bronchitis
if exposures are sufficiently high for extended
durations. Data from the 24-city study indicate
significant differences in acute bronchitis
between high- and low-acid communities. Also
H2SO4 alters the biochemistry of mucus. This
constellation of effects is poorly understood
at present, but represents an area of concern.
New research has illustrated the importance
of acid aerosol composition and the number
of particles, in addition to the mass of hydro-
gen ion. Acid sulphate aerosols in the ambient
air are a mixture of H2S04 and ammonium
bisulphate (NH4(H)S04). Several studies in
humans and animals have shown that H2SO4
is more potent, but the reasons are only now
becoming understood. Even at equivalent
hydrogen ion (H*) concentrations, H2SO4 was
more potent than NH4(H)S04. Other studies
using guinea pigs showed that responses
were dependent on both number concen-
tration and mass concentration of H2SO4.
These interdependences may be responsible
for some of the anomalies within the acidic
aerosol database; they indicate that monitor-
ing to predict effects needs to encompass
more than mass of H+. Knowledge of exact
causative factors associated with the aerosol
could be important to the development of
effective control strategies.
Interactions of ozone and H2SO4 were
studied in 1993 as part of the development
of a revised U.S. Ozone Criteria Pollutant
Support Document. The results show that the
interaction is dependent on the exact nature
of the exposure and the endpoint. Even when
one endpoint is examined, both antagonism
and synergism have been observed, depend-
ing on the concentrations of ozone and H2SO4.
In addition, ultra-fine H2S04 caused more
effects than fine H2SO4 in mixtures with ozone.
Acidic aerosols are a subfraction of ambient
total suspended paniculate matter. Recent
ambient air monitoring data from a number of
studies have demonstrated that acidic aerosols
are concentrated in the fine (<2.5 Mm) and
ultra-fine (<0.1um) fractions (um=micrometre).
Because of their size, these aerosols are more
likely to enter the respiratory system and bypass
many of the body's natural defence mechanisms.
41
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Significant progress has been made in charac-
terizing personal exposures to participate mat-
ter, including acidic aerosols. This information
will be important in developing exposure
estimates and assessing risks resulting
from ambient acidic aerosol concentrations.
In summary, many of the new findings raise
important questions concerning the potential
health risk posed by ambient airborne acidity.
The data confirm the potential for ambient
acidic aerosols to affect lung health in chil-
dren and for important interactions between
acidic aerosols and other ambient pollutants
to adversely impact on human health. The
impact of and regulatory issues related to
acidic aerosols will be considered under
the technical/peer reviews for ambient parti-
culate matter in standard/guideline setting
by the respective agencies in both countries.
QUALITY ASSURANCE
A variety of activities are being carried out
to ensure that the data collected under both
countries' programs are comparable and have
credibility. For example, routine laboratory
comparison studies are being conducted to
ensure that the data produced for terrestrial,
atmospheric, and aquatic programs are com-
parable. For the terrestrial program, six stud-
ies have been completed, and they show
continual improvement in the laboratory
measurement process. The most recent
study included 23 laboratories analyzing
plant tissues for metals and nutrients.
Similarly, three comparisons are being carried
out annually to support the atmospheric and
aquatic programs. Laboratories are requested
to analyze about 25 different constituents in
10 different water samples. These test samples
include natural rainwaters and soft surface
waters collected from Canadian and U.S. acid
rain watersheds. Thirty-three studies have
been completed since December 1982, with
over 130 Canadian and U.S. laboratories
participating in the studies. The results of
these studies are maintained on a database
and are available for further analysis.
In other activities, sampling equipment has
been co-located to compare Canadian and
U.S. measurement techniques. At Egbert,
Ontario, almost two years of CAPMoN and
NDDN measurements are available. Median
values associated with all measurements
collected from the fourth quarter of 1990 to
the third quarter of 1992 are listed in Table 5.
The NDDN and CAPMoN differences are very
small (less than or equal to the precision
determined for collocated sites within NDDN)
for sulphate, ammonium, and total nitrate.
Larger differences are noted for SO2.
An expansion of this activity is now under
way. Wet deposition sampling equipment
was installed at Scotia Range, Pennsylvania,
during the first quarter of 1993. This site was
selected because it will permit comparison
of all three major wet deposition networks
in North America. Precipitation samples are
collected according to network-specific sched-
ules (NADPN/NTN and NDDN are weekly and
CAPMoN is daily) and analyzed by the network
laboratories. There is no sample splitting
among laboratories. This effort represents
the best chance for assessing overall network
comparability, since it covers both field and
laboratory operations.
Table 5 Comparison of Canadian CAPMoN and U.S. NDDN Filterpack
Measurement of Acidifying Air Pollutants (micrograms per cubic metre)
.
Egbert, Ontario
Mean NDDN1
Mean CAPMoN2
Median AD
Median APD
Sulfate
(ug/m3)
3.93
3.92
0.14
3.94
#
*
Nitrate
(M9/m3)
2.39
2.31
0.26
14.77
Ammonium ,
(M9/m3)
1.73-
1.7S .,
0.08 -
6.05
-- __..._. — »....
Nitric
Add
(pg/m3)
1.34
1.39
0.13
12.75
Sulphur
Dioxide
(pgAn3)
5.90
6.60
0.73
14.74
Total
Nitrate
(pg/m3)
3.78
3.70
0.24 ;
5,62 ;
42
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CONTROL TECHNOLOGIES
Canada
Work in Canada is ongoing to develop,
demonstrate, and deploy technologies to
reduce emissions of SO2 and NOx. This work
involves many government agencies at both
the federal and provincial levels and major
industrial partners such as metals companies
and electric utilities. For example, at several
Canadian smelters, intensive industrial
research has led the way to major modern-
ization programs that feature advanced tech-
niques for milling, beneficiation, smelting,
and capturing SO2 as a useful by-product.
At power plants, new technologies — such
as fluidized-bed combustion (FBC) and lime-
stone injection into furnaces, and activation
of unreacted calcium (LIFAC) — result in
large volumes of solid wastes; Environment
Canada has conducted extensive studies to
characterize and assess pollution control
requirements for these wastes. In order
to mitigate or eliminate the adverse environ-
mental effects associated with such residues,
Environment Canada has published a report
called Interim Recommended Practices for
the Management of Solid Residues from
Circulating Fluidized Bed Combustion (CFBC).
Environment Canada also published
Environmental Codes of Practice for
Steam Electric Power Generation-Operations
Phase and Environmental Codes of Practice
for Steam Electric Power Generation-
Decommissioning Phase. These are the
fourth and fifth in a series of five documents
developed for steam electric power plants.
These documents are intended to show that
adverse environmental impacts associated
with the operation of electric generating
stations can be mitigated.
Additionally, Environment Canada has
collaborated with the Canadian Electrical
Association, utilities, and industries on varied
projects including combining technology to
reduce NOx emissions with flue gas desul-
phurization wet scrubber technology to
reduce S02 emissions, identifying additives
that enhance the formation of larger gypsum
crystals in S02 scrubbers, and investigating
NOx formation in power plant plumes.
Similarly, the Canadian Coal Gasification
R&D Committee is studying integrated coal
gasification combined cycle {ICGCQ as a
clean coal technology option for Canada.
Environment Canada is also working with
Nova Scotia Power on pilot scale testing
of conventional selective catalytic reduction
(SCR) of NOx in a high-sulphur content
Canadian coal.
Government-industry sponsored research
programs on a range of S02 and NOx emission
control technologies applicable to Canadian
sources are continuing. In many cases, these
programs draw directly on developments or
industry experience in the United States and
other countries.
United States
Considerable progress has been made in
the development of control technologies. In
the United States, the Clean Coal Technology
(CCT) Program will fund almost $7 billion
in projects over the course of the decade.
The power-generating and pollution-control
technologies developed in this government-
business research and development program
are initiatives aimed at emission reductions
and cost and operation efficiencies. The
initiative, lead by the U.S. Department of
Energy, is intended to demonstrate the utility
and merit of new coal-burning processes in
a series of full-scale commercial facilities.
The CCT Program continues to place empha-
sis on mitigation of acid rain precursor emis-
sions. This focus is consistent with the U.S.
and Canadian Special Envoys Report on Acid
Rain, the source of the original 1986 recom-
mendation for a multi-billion dollar clean-
coal demonstration program.
All five competitive solicitations under the
CCT Program have been completed. There
are currently 45 active projects in the CCT
Program. Three projects have been completed,
21 are in operation, and 16 projects are in
the design phase or under construction. The
remaining five projects are in negotiation. Of
the 45 projects selected under the first three
CCT solicitations, almost all will have had
sufficient operating time by the year 2000
to be offered commercially. Once the projects
are completed, both sponsors and participants
will use information and experience gained
to promote and market the technologies in
commercial applications. Total project costs
through the five solicitations under the
-------
program amount to approximately $6.9 billion,
with the average industry cost share being
66 percent.
Achievements to date (by market category)
under the Clean Coal Technology Program
are summarized below:
• Advanced power generation systems.
Development of a commercial replication
of the atmospheric circulating fluidized-bed
combustion (ACFB) technology at 100
megawatt (MW) scale was a direct result
of demonstrating the technology under
the program at the Colorado-Ute Electric
Association Nucla Station between 1988
and 1991. At the time of demonstration
it was the largest ACFB plant at 110 MW.
While ACFB was finding its way into the
marketplace, operations began under
the program on the first U.S. application
of pressurized fluidized-bubbling-bed
combustion (PFBC) at utility scale (70 MW).
Approximately three years of pioneering
work led to the establishment of a sound
database. As work on the PFBC unit nears
completion, construction of a circulating bed
version is set to get under way so that this
alternate approach also can be evaluated.
Seven different approaches to integrated
gasification combined cycle, an inherently
efficient and clean technology, are in various
stages leading to full-scale system integra-
tion and analysis. The projects in place cover
a broad spectrum of gasifier types, coals,
sorbents, diluents, oxygenates, and operating
conditions. To further expand the technology
options being explored, selections under
round 5 include an indirect coal-fired cycle,
a second generation PFBC, a coal-fired
diesel, and an integrated gasification fuel cell.
• Environmental control systems. Two
advanced flue gas desulphurization tech-
nologies in operation have been routinely
achieving over 95 percent S02 capture and
producing wallboard-grade gypsum. Several
combined S02/NOx control systems are in
operation and exceeding design goals. One
of these systems is achieving 96-percent SO2
reduction and 94 percent NOx reduction
while producing 93 percent pure sulphuric
acid and no solid waste. Six NOx control
options covering the full range of boiler
types are in the later stages of scale up.
Three of these systems have been adopted
for commercial use by the host utility. At
least one commercial sale to an operation
other than the host utility has been realized
for one of the technologies. As emissions
reductions are realized over the next 15
years, opportunities to use other technolo-
gies as they become available will increase.
• Coal process for clean fuels. These tech-
nologies are characterized by production
of high-energy density solid, stable compli-
ance fuels and production of coal-derived
liquids that can be used as chemical or trans-
portation fuel feedstocks. Both the Rosebud
Syncoal coal upgrading project and the
ENCOAL mild gasification project are
producing products at the target capacity
of 1,000 tons per day. Testing of the solid
and liquid products by potential users
is in progress.
• Industrial applications. This category
encompasses the steel industry, cement
industry, and industrial boiler applications.
Dealing with coke oven emissions is the
key concern of the steel industry. An early
effort under the program to control coke
oven gas emissions was slowed by an
unrelated shutdown of the coke ovens.
Another effort to substitute coal for at
least 40 percent of the coke has proceeded
to construction. A third project aimed at
eliminating the need for coke is in negotia-
tion. Complete success was realized for a
coal-fired cement kiln application that may
have broader application in the paper pro-
duction and municipal waste incineration
areas. Cement kiln waste was used to
achieve 90 percent SO2 reduction, produce
fertilizer, convert the kiln waste to cement
feedstocks, and eliminate all waste streams.
Cement, municipal waste, and paper pro-
duction plants in the United States and
abroad are actively considering adoption
of this technology.
Finally, Canada and the United States continue
to hold an annual meeting on control tech-
nologies under a bilateral Memorandum
of Understanding. Status reports on their
respective CCT programs are given at the
annual meeting.
44
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MARKET-BASED MECHANISMS
Canada
Canada's acid rain program has substantially
achieved the SO2 emissions reductions
required under the Canada-U.S. Air Quality
Agreement. However, discussions are under
way between the federal government and
several provinces on the feasibility of apply-
ing economic instruments as a cost-effective
way of achieving emissions reductions.
United States
The Acid Rain Program under the 1990 Clean
Air Act (CAA) Amendments represents the
largest use of market-based mechanisms
to achieve environmental protection in the
world. Innovative market-based approaches,
some in combination with traditional com-
mand-and-control approaches, are believed
to reduce the overall costs of compliance
and stimulate innovation in pollution reduc-
tion methods. The market-based emissions
allowance system under the Acid Rain
Program has been estimated to reduce
costs of compliance. The reductions are
considered significant given that costs of
compliance with Phase I of the Acid Rain
Program have been projected to increase
from $1 billion in 1997 and $1.3 billion in
2000 to $2.1 billion in 2005. In 2010 costs
are expected to reach $2.2 billion for SO2
compliance. The potential cost savings from
a market-based system range from 25 to 50
percent. Over 326,000 emission allowances
were sold during public auctions in March
of 1993 and 1994; also, more than a dozen
two-party and brokered trades have been
reported involving the sale of over 1 million
allowances valued at about $200 million.
Further trading and additional private auc-
tions are expected to occur now that EPA's
Allowance Tracking System is in place.
There are numerous other examples beyond
the U.S. Acid Rain Program of innovative
market incentive programs aimed at achiev-
ing pollution reductions under the CAA
Amendments. One example is EPA's Cash
for Clunkers Program, which by encouraging
fleet turnover promotes the removal from
service of older vehicles that tend to be more
polluting. Vehicles can be sold to program
sponsors, which can include participating state
and local governments or industries such as
power companies, petroleum refineries, and
steel mills. Vehicle owners are encouraged
to participate in the program by the opportu-
nity to avoid high maintenance bills that
older vehicles tend to incur. Since newer
models meet more stringent emission limits,
drivers can put their profits toward purchases
of new cars and still net important emissions
reductions.
By retiring older "dirty" vehicles, sponsors
earn emissions credits to offset their own
emissions requirements or to sell to other
companies. EPA guidelines establish meth-
ods to calculate credits and to ensure that
the program removes dirty in-use vehicles
from the nation's roads, rather than from
the nation's junk yards.
Some states, including Massachusetts and
California, have established initiatives in
the area of market incentives for air pollution
reductions. In each case, the goal is to ensure
pollution reduction while providing for flexi-
bility and financial incentives to stimulate
innovation and technological advancement.
Massachusetts recently unveiled a statewide
emissions banking and trading program
allowing companies that reduce air pollution
below regulatory requirements to trade or
sell the additional reductions to companies
that need those credits to build or expand
their own operations in the state. Under the
CAA Amendments, any new source of air pol-
lution, such as a factory, must find offsetting
pollution reductions amounting to 120
percent of what is expected to be emitted.
Finally, California's South Coast Air Quality
Management District (AQMD) has developed
an emissions trading program called the
Regional Clean Air Initiatives Market
(RECLAIM) for the Los Angeles area. The
program would set annual emissions limits
for over 450 major NOx emitting sources and
approximately 40 major S02 emitting sources
in Los Angeles, Orange, Riverside, and San
Bernardino counties, the air basin suffering
the worst air pollution in the United States.
The limits on NOx and S02 would decrease
each year to curb the area companies' emis-
sions by 80 percent and 65 percent respec-
tively by 2003. Companies would choose
their own cost-effective compliance plans,
and those companies reducing emissions
beyond their annual limits could sell
45
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pollution credits to others. AQMD expects
that the costs of meeting the goal would
be about half that of regular smog control.
Approximately 400 businesses would
save an estimated $93 million a year.
ASSESSMENT OF THE COSTS,
BENEFITS, AND EFFECTIVENESS
OF CLEAN AIR CONTROLS
Canada
Canada has achieved its required SO2 emis-
sions reductions by relying on a mix of regu-
lations, voluntary approaches, and public
education, with each province determining
its own cost-effective mix depending on the
nature of the S02 sources in its jurisdiction.
This approach has resulted in about a
40 percent reduction in S02 emissions
from 1980 levels.
However, scientists are predicting that parts
of Canada will still be acidified after the year
2000. As a result, Canada is now developing
a new National Strategy on Acid Rain for
the post 2000 period to protect acid-sensitive
areas. An economic analysis of the various
measures to reduce S02 emissions will be
central to the development of the new strategy.
United States
Numerous efforts are under way to evaluate
the costs, benefits, and effectiveness of the
Acid Rain Program in the United States.
Research efforts in the 1980s created baselines
in various areas, particularly acid rain impact
areas, with which to track and compare data
following implementation of the CAA Amend-
ments. The Acid Rain Program, in particular,
benefits from years of research that can be
used to compare current and future data.
Furthermore, because the Acid Rain Program
is one of the first attempts at environmental
protection using a market-based approach,
it lends itself to analysis of the effectiveness
of market-based approaches compared with
traditional command-and-control approaches.
Under the directive of several different sections
of the CAA Amendments, assessment and
evaluation of the Acid Rain Program are
planned and are currently under way. Section
812 of the Amendments requires EPA to assess
the costs and benefits of the entire CAA. The
assessment requirement is both retrospective
(1970-1990) and prospective (in terms of projec-
tions regarding expected costs, benefits, and
other effects of compliance pursuant to the
act). Since acid rain legislation was new to the
act upon passage of the 1990 Amendments, the
Section 812 analysis is particularly relevant to
the Acid Rain Program, and numerous efforts
to assess and forecast the costs and benefits
of the Acid Rain Program have been initiated.
Evaluation of the Acid Rain Program also will
be addressed under Section 901 of the CAA
Amendments. Under this requirement, the
National Acid Precipitation Assessment
Program (NAPAP) will issue a report to the
Congress in 1996 and every four years there-
after on costs, benefits, and effectiveness of
Title IV. The Acid Deposition Standard Study,
under Appendix B, Section 404, of the CAA
Amendments, will also provide insight to
the environmental effectiveness and costs
of the Acid Rain Program.
Furthermore, efforts to effectively track and
evaluate the environmental impact of the Acid
Rain Program (e.g., deposition of acidic com-
pounds and surface water chemistry) are on-
going. Finally, regarding Title II (mobile sources)
of the CAA Amendments, EPA is required to
make a determination by the end of 1999 on
the need to further reduce NOx emissions from
vehicles with more stringent emission standards.
46
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SECTION IV
Areas of Future
Cooperation — Ground-Level Ozone
ONGOING COOPERATION
The initial focus of the Canada-U.S. Air
Quality Agreement was acid rain. Annex I of
the Agreement specifies emissions reduction
targets and timeframes for attaining them.
The overall purpose of the Agreement, how-
ever, is to provide a practical and flexible
instrument to deal with shared problems of
transboundary air pollution. The Air Quality
Committee is responsible for informing each
country about the other's activities in areas
relating to air quality.
The two subcommittees under the Air Quality
Committee met in April 1993, in Washington,
DC. At the meeting, the Subcommittee on
Program Monitoring and Reporting reviewed
existing ozone regulations and activities
in Canada and the United States, and the
Subcommittee on Scientific Cooperation
reviewed existing ozone research efforts
in both countries. This marked the beginning
of information-sharing under the Air Quality
Agreement on the issue of ground-level ozone.
Both governments agreed that joint Canada-
U.S. scientific research on air quality modelling,
transboundary flows, and pollutants effects
on health should continue so that the best
solutions can be selected. The North American
Research Strategy on the Tropospheric Ozone
Program was identified as the vehicle of choice
to ensure a consistent approach. It also was
agreed that inventory analysis and appropriate
airshed modelling are important components
of future efforts to find permanent solutions
to present ambient air quality problems.
The Ozone Transport Commission's plan for
ozone reduction in the eastern region will
also help focus on the priority actions required
to address ground-level ozone problems in
the Windsor-Quebec Corridor and Southern
Atlantic Region.
At a meeting in the fall of 1993, Canada and
the United States agreed to produce a report
on the progress of implementation of the
U.S. Clean Air Act Amendment actions
and Canadian NOx/VOC Management Plan
requirements in the neighbouring regions.
EXISTING GROUND-LEVEL
OZONE PROGRAMS
The following programs relating to ground-
level ozone were reported at the April 1993
meeting of the bilateral Subcommittee on
Program Monitoring and Reporting.
Canada
In Canada, the National Ambient Air Quality
Objective (NAAQO) is 82 ppb (0.82 ppm) maxi-
mum averaged over 1 hour. This is not a stan-
dard but a target for national and regional
measures to reduce NOx and VOC emissions.
Some provinces have adopted the objective
as a standard.
Three regions in Canada periodically experi-
ence ozone levels above the national objec-
tive: the Lower Fraser Valley (LFV) of British
Columbia, the Windsor-Quebec Corridor
(WQC) portion of Ontario and Quebec, and
the South Atlantic Region (SAR) around
Saint John, New Brunswick.
Elements of an emission reduction program
were adopted in a NOx/VOC Management
Plan adopted by the Canadian Council of
Ministers of the Environment (CCME) in 1990.
The Canadian plan is comprised of three parts:
(1) a national prevention program to imple-
ment NOx and VOC emissions reductions in
selected industrial and mobile source sectors
in all of Canada, along with a public education
campaign to help consumers reduce the
impact of their everyday activities on the
environment; (2) a regional remedial program
(addressed to the high-ozone areas of the LFV,
the WQC, and the SAR) to implement new
NOx and VOC emission limits in existing
stationary facilities and develop local trans-
portation management programs; and (3)
a scientific program to complete inventories,
analyze the data, develop and validate models,
improve monitoring networks, understand
meteorological factors, and develop sce-
narios to assess future emission reduction
requirements.
47
-------
In addition, the Canadian government plans
to implement mobile source and energy effi-
ciency standards for appliances and build-
ings. Provincial and local jurisdictions will
implement other point and area sources and
limits. All requirements of the program have
been or will be developed through the multi-
stakeholder process involving governments,
industry, and environmentalists working
together to select consistent and cost-
effective measures.
United States
In the United States, the National Ambient
Air Quality Standards (NAAQS) were estab-
lished for ozone to protect public health and
welfare. The health and welfare standards are
both set at 0.12 ppm (120 ppb) averaged over
one hour with no more than one expected
exceedance per year. Areas in the United
States that do not meet the ozone NAAQS
are required by law to be formally designated
by EPA as nonattainment (NA) areas for that
pollutant. Each designation is based upon a
submittal by the appropriate state governor.
The CAA also provides a system to classify
or group NA areas according to the severity
of the problem. The classification system is
contained in Section 181(a) of the 1990 CAA
Amendments and is composed of six cate-
gories (Table 6). Ozone control programs and
other requirements are tied directly to the
designation and classification of an NA area.
Dates by which the U.S. Congress expects air
quality to meet standards (attainment dates)
are also prescribed (see Table 6) and vary
with the severity of the NA problem.
The CAA requires a three-part approach to
address ozone: (1) national rules established
by the federal government (e.g., automobile
tail pipe standards); (2) mandatory area-
specific rules and progress requirements
adopted by states, increasing in stringency
with the ozone classification; and (3) reduc-
tions needed to meet the NAAQS by a
prescribed date.
States must implement ozone control
requirements to bring NA areas into attain-
ment with NAAQS. The United States is in
the process of reviewing its ozone standard.
A decision to retain or revise the current
standard will be made in the next few years.
CONCLUSION AND NEXT STEPS
This second Progress Report under the
Canada-U.S. Air Quality Agreement docu-
ments major efforts in both countries toward
achieving emission reduction goals. This
report also focuses on scientific and technical
activities undertaken by both countries to
assess, monitor, and mitigate air pollution.
In both countries, government and industry
have moved forcefully and expeditiously
toward achieving these goals. Both countries
are committed to conducting ongoing moni-
toring and technical activities in order to
report on the status of the acidic deposition
problem. In addition, the two countries
continue to study the effects of acidic com-
pounds on human health. Both countries
also are demonstrating and deploying new
pollution control technologies in an effort
to reduce pollution while using indigenous
fuels for energy production.
The two countries share an interest in various
air quality problems beyond acidic deposition,
including tropospheric ozone (smog) and the
deposition of toxic compounds. Both countries
have designed pollution control programs
Table 6 Classification of U.S. Ozone Nonattainment Areas
Classification
Concentration
Years Given
to Attain
Marginal
, 0.121 yp to tJ.138
3 years
Moderate
0438 «p to" 0,160
6 years
Serious
0.160 up to (Mao
9 years
Severe-15
0.180 wp to 0,130
15 years
Severe-17
0.190 up to 0.280
17 years
Extreme
0.280 and above
/ Nov. 15,2020
20 years
48
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to reduce levels of ozone and air toxics. The
two countries are currently reviewing their
standards for ground-level ozone, with Canada
expecting to complete its review in 1994 and,
in the United States, issuance of a final
decision in 1997.
Canada and the United States have embarked
on long-term programs to reduce the effects
of acid rain in the two countries. In 1995, emis-
sion reductions in the United States under the
new Acid Rain Program will commence and
will increase reductions already achieved. In
1995, Canada will report on its efforts to pro-
tect visibility and to prevent significant deteri-
oration (i.e., "keeping clean areas clean").
In the United States, Phase II sources will
install continuous emission monitors and
develop strategies for Phase II reduction.
In both countries, different methods of
reducing emissions will continue to be
employed, including energy efficiency,
demand-side management, fuel switching,
and pollution control equipment. Similarly,
deposition, air concentrations, surface
waters, and forests will continue to be moni-
tored and results will be compared with past
estimates. Both countries will continue to
assess the health effects associated with
acidic deposition and ground-level ozone.
Finally, both countries are in the process
of assessing the need for and consequences
of further emission reductions to protect
critically sensitive ecosystems.
49
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United States-Canada
Air Quality Committee
APPENDIX A
Canada
Co-chair
Tony Clarke
Assistant Deputy Minister
Environmental Protection Service
Environment Canada
Members
Frangois Guimont
Acting Director General
Pollution Prevention Directorate
Environment Canada
Phil Merilees
Director General
Research
Atmospheric Environment Service
Environment Canada
John Lowe
Director
International Trade and
U.S. Relations Division
Natural Resources Canada
David McLellan
Deputy Director
U.S. Transboundary Division
Foreign Affairs and
International Trade Canada
Larry Lechner
Director
Air and Land Protection Branch
Saskatchewan Environment and Public Safety
Walter Chan
Assistant Director
Science and Technology Branch
Ontario Ministry of the
Environment and Energy
Laval Lapointe
Direction de la coordination
de I'expertise technique
Ministere de I'Environnement et de la Faune
Derrick Maddocks
Director of Industrial
Environmental Engineering Division
Newfoundland Department of
Environment and Lands
United States
Co-chair
Rafe Pomerance
Deputy Assistant
Secretary of State
Department of State
Members
Mary Ann Peters
Deputy Assistant Secretary
for European and Canadian Affairs
Department of State
Paul Stolpman
Director
Office of Atmospheric Programs
Environmental Protection Agency
David Kee
Director
Air and Radiation Division
Environmental Protection Agency, Region 5
Abraham Haspel
Deputy Assistant Secretary
for Economic & Environmental Policy
Department of Energy
Bruce Hicks
Director
Air Resources Laboratory
National Oceanics and
Atmospheric Administration
Molly Ross
Special Assistant to the Assistant Secretary
for Fish, Wildlife and Parks
Department of Interior
51
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SUBCOMMITTEE ON PROGRAM
MONITORING AND REPORTING
Co-chairs:
Wayne Draper
Associate Director
Air Issues Branch
Environment Canada
Brian McLean
Director, Acid Rain Division
Office of Atmospheric Programs
Environmental Protection Agency
SUBCOMMITTEE ON
SCIENTIFIC COOPERATION
Co-chairs:
Keith Puckett
Acting 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
TERMS OF REFERENCE
U.S.-Canada
Air Quality Committee
1. Review progress made in the implemen-
tation of the Agreement, including 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. Release each progress report to the
International Joint Commission for
action is 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 additionally
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 information has
been acquired.
Subcommittee on Program
Monitoring and Reporting
1. Coordinate activities as outlined in para-
graph 2 of Annex 2 to the Agreement 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 tech-
nologies and measures for controlling
emissions of air pollutants, in particular,
acidic deposition precursors, subject to
respective laws, regulations, 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 mecha-
nisms, including emission trading, 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 purposes
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, recom-
mendations to the Air Quality Committee
on operational guidelines for implemen-
tation of Article V(2), and cooperate and
exchange information regarding imple-
mentation of sections 3 and 4 of Annex 1
to the Agreement.
6. Assist the Air Quality Committee in review-
ing progress made in the implementation
of the Agreement, including its general
and specific objectives, as required under
Article VIII of the Agreement, with respect
to areas within its purview.
52
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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 required under
Article VIII.
9. Establish ad hoc bilateral working groups
as may be required to fulfil the above
responsibilities.
Subcommittee on
Scientific Cooperation
1. Coordinate air pollutant monitoring activi-
ties as set forth in paragraph 1 of Annex 2
to the Agreement for the purpose of deter-
mining and reporting on air pollutant con-
centrations and deposition.
2. Cooperate and exchange information on
their monitoring of the effects of changes
in air pollutant concentration and deposi-
tion, with respect to changes in various
effects categories, e.g., aquatic ecosys-
tems, 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 subpara-
graph 3(b) of Annex 2 to the Agreement.
4. Cooperate and exchange information on
the development and refinement of atmos-
pheric models for purposes of determining
source receptor relationships and trans-
boundary transport 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
information and results of research on,
methods to mitigate the impacts of acidic
deposition, including the environmental
effects and economic aspects of such
methods, as set forth in paragraph 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 fulfil the above
responsibilities.
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APPENDIX B
Agreement Between the Government
of the United States of America and the
Government of Canada on Air Quality
The Government of the United States of
America and the Government of Canada,
hereinafter referred to as "the Parties,"
Convinced that transboundary air pollution
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 result
in significant transboundary air pollution;
Convinced that transboundary air pollution
can effectively be reduced through coopera-
tive or coordinated action providing for con-
trolling emissions of air pollutants in both
countries;
Recalling the efforts they have made to con-
trol 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 Stockholm
Declaration, which provides that "States
have, in accordance with the Charter of the
United Nations and the principles of interna-
tional law, the sovereign right to exploit their
own resources pursuant to their own envi-
ronmental policies, and the responsibility to
ensure that activities within their jurisdiction
or control do not cause damage to the envi-
ronment of other States or of areas beyond
the limits of national jurisdiction";
Noting their tradition of environmental coop-
eration 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 Pollution of 1979;
Convinced that a healthy environment is
essential to assure the well-being of present
and future generations in the United States
and Canada, as well as of the global community;
Have agreed as follows:
ARTICLE I
Definitions
For the purposes of this Agreement:
1. "Air pollution" means the introduction by
man, directly or indirectly, of substances
into the air resulting in deleterious effects
of such a nature as to endanger human
health, harm living resources and ecosys-
tems and material property and impair or
interfere with amenities and other legiti-
mate uses of the environment, and "air
pollutants" shall be construed accordingly;
2. "Transboundary air pollution" means air
pollution whose physical origin is situat-
ed 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 Commission estab-
lished by the Boundary Waters Treaty.
ARTICLE II
Purpose
The purpose of the Parties is to establish,
by this Agreement, a practical and effective
instrument to address shared concerns
regarding transboundary air pollution.
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ARTICLE III
General Air Quality Objective
1. The general objective of the Parties is
to control transboundary air pollution
between the two countries.
2. To this end, the Parties shall:
(a) in accordance with Article IV, establish
specific objectives for emissions limita-
tions or reductions of air pollutants and
adopt the necessary programs and under
measures to implement such specific
objectives;
(b) in accordance with Article V, undertake
environmental impact assessment, prior
notification, and, as appropriate, mitiga-
tion measures;
(c) carry out coordinated or cooperative
scientific and technical activities, and
economic research, in accordance with
Article VI, and exchange information,
in accordance with Article VII;
(d) establish institutional arrangements, in
accordance with Articles VIII and IX; and
(e) review and assess progress, consult,
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 objec-
tives, 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.
2. Each Party's specific objectives for emis-
sions limitations or reductions of sulphur
dioxide and nitrogen oxides, which will
reduce transboundary flows of these
acidic deposition precursors, are set forth
in Annex 1. Specific objectives for such
other air pollutants as the Parties agree
to address should take into account, as
appropriate, the activities undertaken
pursuant to Article VI.
3. Each Party shall adopt the programs and
other measures necessary to implement 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 accordance
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 trans-
boundary air pollution, including consider-
ation of appropriate mitigation measures.
2. Each Party shall notify the other Party
concerning a proposed action, activity
or project subject to assessment 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 accordance with Article XI.
3. In addition, each Party shall, at the
request of the other Party, consult in
accordance with Article XI concerning
any continuing actions, activities or
projects that may be causing significant
transboundary air pollution, as well as
concerning changes to its laws, regula-
tions 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 include consideration
of appropriate mitigation measures.
5. Each Party shall, as appropriate, take
measures to avoid or mitigate the poten-
tial risk posed by actions, activities or
projects that would be likely to cause or
may be causing significant transboundary
air pollution.
56
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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 order
to improve their understanding of trans-
boundary air pollution concerns and to
increase their capability to control such
pollution.
2. In implementing this Article, the Parties
may seek the advice of the International
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
mechanisms for controlling emissions;
(d) atmospheric processes; and
(e) effects of air pollutants, as
provided in Annex 2.
2. Notwithstanding any other provisions
of this Agreement, the Air Quality
Committee and the International Joint
Commission shall not release, without
the consent of the owner, any information
identified to them as proprietary informa-
tion under the laws of the place where
such information has been acquired.
ARTICLE VIII
The Air Quality Committee
1. The Parties agree to establish and main-
tain a bilateral Air Quality Committee
to assist in the implementation of this
Agreement. The Committee shall be com-
posed of an equal number of members
representing each Party. It may be sup-
ported by subcommittees, as appropriate.
2. The Committee's responsibilities
shall include:
(a) reviewing progress made in the imple-
mentation of this Agreement, 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 Commission 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 appropriate, on each
progress report prepared by the Air
Quality Committee pursuant to Article VIII;
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b) to submit to the Parties a synthesis of
the views presented pursuant to sub-
paragraph (a), as well as the record of
such views if either Party so requests; and
(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 International
Joint Commission as may be appropriate
for the effective implementation 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 presented to
the International Joint Commission on
that report in accordance with Article IX,
the Parties shall consult on the contents
of the progress report, including any
recommendations therein.
2. The Parties shall conduct a comprehen-
sive review and assessment of this
Agreement, and its implementation,
during the fifth year after its entry in
to force and every five years thereafter,
unless otherwise agreed.
3. Following the consultations referred to in
paragraph 1, as well as the review and
assessment referred to in paragraph 2,
the Parties shall consider such action
as may be appropriate, including:
(a) the modification of this Agreement;
(b) the modification of existing policies,
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 consultations,
unless otherwise agreed by the Parties.
ARTICLE XII
Referrals
With respect to cases other than those sub-
ject to Article XIII, if, after consultations in
accordance with Article XI, an issue remains
concerning a proposed or continuing action,
activity, or project that is causing or would
be likely to cause significant transboundary
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 between
the Parties over the interpretation or the
implementation of this Agreement, they
shall seek to resolve such dispute by
negotiations between them. Such negoti-
ations shall commence as soon as practi-
cable, but in any event not later than
90 days from the date of receipt of the
request for negotiation, unless otherwise
agreed by the Parties.
2. If a dispute is not resolved through nego-
tiation, the Parties shall consider whether
to submit that dispute to the International
Joint Commission in accordance with
either Article IX or Article 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, submit
the dispute to another agreed form
of dispute resolution.
ARTICLE XIV
Implementation
1. The obligations undertaken under this
Agreement shall be subject to the avail-
ability of appropriated funds in accor-
dance with the respective constitutional
procedures of the Parties.
58
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2. The Parties shall seek:
(a) the appropriation of funds required
to implement this Agreement;
(b) the enactment of any additional legisla-
tion that may be necessary to implement
this Agreement;
(c) the cooperation of State and Provincial
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 obligations of the
Parties in other international agreements
between them, including those contained
in the Boundary Waters Treaty and the Great
Lakes Water Quality Agreement of 1978,
as amended.
ARTICLE XVI
Entry into Force,
Amendment, Termination
1. This Agreement, including Annexes 1 and
2, shall enter into force upon signature
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 annex
so provides, either Party may terminate
such annex in accordance with the terms
of that annex.
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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 Title IV of the Clean Air Act3 i.e.,
reduction of annual sulphur dioxide
emissions to approximately 10 million
tons below 1980 levels by 2000 (with
the exception of sources repowering
with qualifying clean coal technology
in accordance with section 409 of the
Clean Air Act, and sources receiving
bonus allowances in accordance 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 required
by Title IV of the Clean Air Act.
3. Promulgation of new or revised stan-
dards 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 indus-
trial sources in the event that the
Administrator of EPA determines
that annual sulphur dioxide emissions
from industrial sources may reasonably
be expected to exceed 5.6 million tons.
B. For Canada
1. Reduction of sulphur dioxide
emissions in the seven easternmost
provinces to 2.3 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 December 31,1999.
2. Achievement of a permanent
national 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 nitro-
gen oxides control program for electric
utility boilers to the extent required by
Title IV of the Clean Air Act:
(a) By January 1, 1995, tangentially
fired boilers must meet an allowable
emission rate of 0.45 Ib/mmBtu, and
dry bottom wall-fired boilers must
meet an allowable emission rate
of 0.50 Ib/mmBtu (unless the
Administrator of EPA determines
that these rates cannot be achieved
using low NOx burner technology).
(b) By January 1, 1997, EPA must set
allowable emission limitations for:
• wet bottom wall-fired boilers;
• cyclones;
• units applying cell burner technology;
and
• all other types of utility boilers.
2. Mobile Sources
Implementation of the following
mobile source nitrogen oxides control
program to the extent required by
Title II of the Clean Air Act:
(a) Light Duty Trucks (LOT) (up to 6,000 Ibs
gross vehicle weight rating (GVWR))
and Light Duty Vehicles (LDV) — stan-
dards for model years after 1993:
Applies only to reductions in emissions in the 48 contiguous states and the District of Columbia.
1 ton = 0.91 tonnes (metric tons).
All references to the Clean Air Act refer to the Act as amended November 15,1990.
60
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LDTs (0 to
3,750 Ibs
. loaded Vehicle
Weight (LVW)
and LDVs
Diesel LDTs
(0 to 3,750 Ibs
IVW) 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
£° * n ^ *
10 yrs/
100,000 miles
0,6 gpm
1.25 gpm
0,97 gpm /;
, ..„., ,>'*.
Useful life5:
In model year 1994, 40 percent of each manu-
facturer'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 5 yrs/
50,000 miles
A,
1
0.7 gpm
1.1 gpm
Gasoline ancf
ibfessi .,/•;
11yrsft20,090
mites ' "., ;,.'
OJS^pnv/ ff-
"Y f
1.53 gpm -/ , '
In model year 1996, 50 percent of each manu-
facturer'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 (HOT) of more than
8,500 Ibs GVWR (after model year
1990):
HOT (effective model
year 1991s)
HOT (model year 1998
and later)
_, 3 r~< ' >' '^ "• '/•
Gasoline and Diesel Engines
5.0 grams per brake
horsepower-hour5 (gb.hp-hr)
4.0 gbhp-hr
Gasoline Engines
Diesel Engines
Light heavy-duty
Medium heavy-duty
Heavy heavy-duty
8 yrs/1 10,000 miles
8 yrs/1 10,000 miles
8 yrs/1 85,000 miles
8 yrs/290,000 miles
B. For Canada
1. Stationary Sources
(a) As an interim requirement, reduction,
by 2000, of annual national emissions
of nitrogen oxides from stationary
sources by 100,000 tonnes below
the year 2000 forecast level of
970,000 tonnes.
(b) By January 1, 1995, development of further
annual national emission reduction require-
ments from stationary sources to be
achieved by 2000 and/or 2005.
2. Mobile Sources
(a) Implementation of a more stringent
mobile source nitrogen oxides control
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 passen-
ger cars; by model year 1996 for light
duty trucks6):
^ -i, ;-;•/."
, Cars and Light
•Duty Trucks
JfttoSJSQIfasLVW)
Light Duty Trucks
, (3,751 to 5,750 Ibs LVW)
5 yrs/80,000 kilometres
(useful life!
0.4 gpm
0.7 gpm
Medium Duty Vehicles (6,001 to 8,500
Ibs GVWR) (By model year 1997s):
; - - :«*p- •:•?-« '
0 to 3,750 Ibs LVW
3J51 to 5,750 Ibs LVW
\ Over 5,750 Ibs VWR
5 yrs/80,000 kilometres
(useful life)
0.4 gpm
0.7 gpm
1.1 gpm
This standard does not apply to diesel-fuelled LDTs (3,751 to 5,750 Ibs LVW).
As set forth in EPA regulations in effect as of the entry into force of this Agreement.
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.
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Heavy Duty Vehicles (over 8,500
Ibs GVWR) (By model year 19986):
8 yrs/110,000 kilometres
(b) Implementation of a more stringent
mobile source nitrogen oxides control
program for diesel-powered vehicles
and engines with standards, 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 1990
(November 15,1990) emitting sulphur
dioxide or nitrogen oxides install and
operate continuous emission monitor-
ing systems or alternative systems
approved by the Administrator of EPA,
to the extent required by section 412
of the Clean Air Act.
2. 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 compara-
ble effectiveness to continuous emis-
sion monitoring, as well as investigate
the feasibility of using and implement,
where appropriate, continuous
emission 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
towards utilizing comparably effective
methods of emission estimation for
sulphur dioxide and nitrogen oxides
emissions from all major industrial
boilers and process sources, including
smelters.
4. Prevention of Air Quality
Deterioration and
Visibility Protection
Recognizing the importance of prevent-
ing significant air quality deterioration
and protecting visibility, particularly for
international parks, national, state, and
provincial parks, and designated wilder-
ness areas:
A. For the United States:
Requirement that the United States
maintain means for preventing signifi-
cant air quality deterioration and pro-
tecting visibility, to the extent required
by Part C of Title I of the Clean Air Act,
with respect to sources that could cause
significant transboundary air pollution.
B. For Canada:
Requirement that Canada, by
January 1, 1995, develop and
implement means affording levels
of prevention of significant air quality
deterioration and protection of visibili-
ty comparable to those in paragraph
A above, with respect to sources that
could cause significant transboundary
air pollution.
C. For Both Parties:
The Parties shall consult, as appropri-
ate, concerning the implementation
of the above.
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ANNEX 2
Scientific and Technical
Activities and Economic Research
For the purpose of determining and reporting
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 pollutants that the
Parties agree should be monitored for
the purposes of this Agreement;
(c) addition of stations or networks where
no existing monitoring facility can perform
a necessary function for purposes
of this Agreement;
(d) the use of compatible data management
procedures, formats, and methods; and
(e) the exchange of monitoring data.
2. For the purpose of determining and
reporting air emissions levels, historical
trends, and projections with respect
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 emissions
information that the Parties agree
should be exchanged for the purposes
of this Agreement;
(b) the use of measurement and estimation
procedures of comparable effectiveness;
(c) the use of compatible data management
procedures, formats, and methods; and
(d) the exchange of air emission information.
3. The Parties agree to cooperate and
exchange information with respect to:
(a) their monitoring of the effects of changes
in air pollutant concentrations and depo-
sition with respect to changes in various
effects categories, e.g., aquatic ecosys-
tems, visibility, and forests;
(b) their determination of any effects of
atmospheric pollution on human 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, possibly
in a critical loads framework;
(c) their development and refinement of
atmospheric models for purposes of
determining source receptor relationships
and transboundary transport and deposi-
tion of air pollutants;
(d) 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;
(e) their analysis of market-based mechan-
isms, including emission trading; and
(f) any other scientific and technical activities
or economic research that the Parties
may agree upon for purposes of support-
ing 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 deposition,
including the environmental effects and
economic aspects of such methods.
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For More Information
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 M3H 5T4
If you are interested in obtaining information on the acid deposition control programs, contact:
IN THE UNITED STATES
Acid Rain Division
Environmental Protection Agency
Mail Code: 6204J
401 M Street, SW
Washington, DC 20460
IN CANADA
Acid Rain Program
Air Issues Branch
Environment Canada
351 St. Joseph Boulevard
Place Vincent Massey - 11th Floor
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International Joint Commission
Commission mixte Internationale
Your Comments on this Report
Would be Appreciated
The international Joint Commission invites
your comments on the Progress Report of
the Air Quality Committee under the Canada-
United States Air Quality Agreement. The
Agreement assigns the Commission, an
independent international organization,
responsibility for inviting public comment
on the report and preparing a synthesis of
the comments received for the Governments
of the United States and Canada and for
public release.
Your comments would be appreciated on the
form below or by letter and should be sent to
one of the following addresses:
Secretary, Canadian Section
International Joint Commission
100 Metcalfe St.
Ottawa, Ontario K1P5M1
Secretary, United States Section
International Joint Commission
1250 23rd Street, NW, Suite 100
Washington, DC 20440
Name:
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Address:
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Comments:
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