CONTROLLING ACID RAIN:
POLICY ISSUES
by
James A. Fay and Dan Golomb
Policy Discussion Series, MIT-EL 83-012
September 1983
This work was funded by the Champion International
Foundation and the Center for Energy Policy Research of
the MIT Energy Laboratory, and that support is gratefully
acknowledged. The authors also are thankful for the
helpful comments of L. C. Cox and J. M.Deutch.
CONTROLLING ACID RAIN:
POLICY ISSUES
James A. Fay and Dan Golomb
Energy Laboratory
Massachusetts Institute of Technology
Cambridge, MA
02139
ABSTRACT
The policy and regulatory ramifications of U.S.
acid rain control programs are examined; particularly,
the alternative of a receptor-oriented strategy as
constrasted to emission-oriented proposals (e.g., the
Mitchell bill) which set sulfur emission reductions
to uniform national levels. In receptor strategies,
goals for deposition reductions in ecologically
threatened areas are determined and the emission
reductions are apportioned primarily to sources that
cause the bulk of acid deposition in those areas. It
is very likely that a receptor-oriented strategy would
be less costly (on a national basis) than a uniform
emission reduction strategy, and certainly more
beneficial to the endangered areas. For a
receptor-oriented strategy, a detailed economic
analysis needs to be performed to select the
least-cost emission control method for the individual
sources. Such methods may include scrubbers,
combustion modification, total or seasonal fuel
substitution, and electricity import (i.e., emission
export). An emission control scheme tailored for
northern New York and New England would also benefit
sensitive areas in southeastern Canada, and thereby
help to defuse the present U.S./Canadian impass over
acid rain control agreements.
Table of Contents
Abstract
i
1.
Introduction
I
2.
The Acid Rain Problem
2
3.
Current Acid Rain Control Proposals
4
4.
Relating Emissions to Deposition
6
5.
Alternative Acid Deposition Control Strategies
7
6.
Policy Implications of Alternative Strategies
10
7.
Transboundary Acid Rain Problems
14
8.
Conclusions
16
References
18
I.
INTRODUCTION
Acid rain,* caused by copious emissions of sulfur and nitrogen oxides
during the combustion of fossil fuels, is said to damage natural
ecosystems in acid-sensitive areas downwind of heavily industrialized
regions of North America and Europe.
To mitigate such damage in the
northeastern U.S. and eastern Canada, a substantial reduction of the
precursor emissions - SO2 and NOx - would be required.
Complete
elimination of such emissions is out of the question and substantial
reductions, while technologically feasible, would be very expensive in
the aggregate. Significant emission reductions could be achieved in the
distant future by phasing out existing high emission sources and
replacing them with new facilities that use either low emission fuel or
novel emission control technology.
In the meantime, "cleaning up"
existing facilities will be difficult and expensive since that requires
retrofitting and modification of time-honored and proven processes.
In
many instances, the lack of a suitable retrofit technology and of storage
and supply routes for cleaner fuels impedes emission reductions.
Nevertheless, in the near future (one to two decades), the bulk of
emission reduction can only be obtained from existing sources.
Currently debated proposals and bills introduced in Congress (e.g.,
the Mitchell bill, S. 146, Congressional Record, 1983) aim at a partial
emission reduction across most of the 31 states east of, or bordering on,
the Mississippi River.
As shown in an accompanying paper (Fay, Golomb, and
*The term acid rain is somewhat of a misnomer. Acid precipitation is
a better term, as snow, fog, dew, hail, etc., all may contain acidic
matter. The distinction should also be made between wet and dry
deposition; the latter term is the adsorption and absorption of dry
vapors and particles on soil, water, vegetation and structure.
2
Gruhl, FGG,
1983),
such partial, across-the-board emission reductions of
only one of the acid rain precursors - SO2 - would reduce the average
precipitation acidity very little.
There is a more cost-effective approach that could benefit
environmentally sensitive areas to a greater extent, which we term a
targeted strategy.
(i)
The elements of a targeted strategy are:
identifying sensitive areas which will benefit from a
reduction of acid deposition,
(ii) determining target levels of deposition reduction needed,
(iii)
relating the geographical distribution of emission reductions
to the reductions of deposition in sensitive areas, and
(iv)
selecting mitigation methods, their cost and manrer of
implementation to minimize aggregate costs.
While a targeted approach may not benefit all impacted areas equally,
the allotted resources can be brought to bear more effectively on
protecting, at least in the interim, the most sensitive areas.
As new
combustion and emission control technology is developed, greater emission
reductions could be achieved among all source areas, thus increasing the
protection of other sensitive areas as well.
In this paper some of the technical aspects and policy ramifications
of a targeted acid rain control strategy will be explored.
2. THE ACID RAIN PROBLEM
While it has been known for more than a hundred years that
precipitation sometimes is quite acidic, only within the past decades has
there arisen a recognition that acid precipitation deleteriously affects
natural ecosystems, especially aquatic life.
Since World War II, first
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in Scandinavia and then in northeastern North America, monitoring of
precipitation acidity and aquatic ecosystems has shown some evidence of
increasingly severe aggregate effects.
The acidity is principally
associated with sulfate and nitrate ions in precipitation.
These ions
are formed from the oxidation of sulfur and nitrogen oxides (SOx and
NOx ) in the atmosphere whose principal sources are the products of
combustion of fossil fuels.
Because these atmospheric oxidation
reactions proceed very slowly, the deposition of sulfate and nitrate ions
occurs at great distances from the point where combustion effluent is
injected into the atmosphere.
In the northeastern U.S., the present average precipitation acidity
is pH 4.2, but spatial and temporal fluctuations of *1 pH unit have been
observed (MAP3S/RAINE, 1982).
Acid precipitation is most noticeable near
regions of heavy industrial activity, such as western Europe and eastern
North America. Within such identifiable areas, estimates of SO2 and
NO x emissions show a ten-to-one preponderance of man-made emissions
over biogenic sources.
In the U.S., about 90 percent of anthropogenic
sulfur is released in the combustion of fossil fuels, about 2/3 of this
by electric generating stations.
Of the total sulfur released into the
atmosphere within the eastern U.S., about 20 percent ends up in acid
precpitation and 80 percent in dry deposition and convective transport by
the wind beyond the region's boundaries (Golomb, 1983).
A similar
proportioning of deposition and transport also holds for nitrogen
oxides.
Of the emission sources of NOx, vehicles (principally the
automobile) account for nearly one-half.
In terms of acidifying
potential, aggregate SOx emissions constitute about two-thirds of the
total and NOx the remaining one-third.
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4
Aquatic ecosystems are adversely affected by acidification.
The
effects may depend on the kind and proportions of anions and cations in
precipitation rather than simply on the net hydrogen ion concentrations.
Many lakes in the northeastern U.S. and eastern Canada have been markedly
affected by acid precipitation because of the lack of natural buffering
capacity, the underlying geologic structure being granite rather than
limestone.
Other terrestrial ecological effects are suspected such as
forest growth stunting and disease, but the evidence is not unambiguous.
Because acid precipitation is widespread, sensitive receptor areas can be
identified by surveying for the early signs of ecosystem deterioration,
principally aquatic populations.
It is these sensitive areas which would
be the principal beneficiaries of reductions of acid precipitation.
Overlaying the maps of poorly buffered areas and present acid deposition
contours, it can be shown that the exposed sensitive areas are confined
to upper New York state, New England, southern Ontario and Quebec and
parts of the Smoky Mountains (FGG, 1983).
3.
CURRENT ACID RAIN CONTROL PROPOSALS
Pending legislative proposals (e.g., the Mitchell bill) for reducing
acid rain impacts are oriented toward controlling utility sulfur
emissions to a nearly uniform level (expressed as sulfur emissions per
unit of fuel heat) throughout a 31 state area of the eastern U.S.*
The
unstated concept is analogous to that of controlling a metropolitan urban
*These proposals focus on sulfur emissions, but allow credit for
reductions of nitrogen oxide emissions. They reflect the much greater
difficulty of achieving significant reductions of nitrogen oxide
emissions and the uncertainty as to whether nitrate acidity is as harmful
to ecosystems as sulfate acidity.
I
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5
airshed where source emission reductions to a uniform emission standard
would result in a commensurate reduction of ambient pollutant levels to
values that are more or less uniform throughout the airshed.
More
significantly, the final level of emissions permitted under the Mitchell
bill is an equitable one in the sense that each source (on average) would
be allowed emissions in the same proportion to fuel used.
Admittedly,
the abatement costs to achieve such a level of reduction would be quite
different among the various sources, the greater cost being incurred by
sources which must reduce emissions the most.
If implemented, it is estimated that the Mitchell bill would result
in a reduction of 45% of the SO2 emissions in the eastern U.S. from the
present level of 22.5 Mty
1
(Friedman, 1981).
This goal would be
achieved over a ten year period principally by retrofitting flue gas
scrubbers to existing power plants, and to a lesser extent by removing
sulfur from coal through cleaning and by replacing high sulfur coal with
low sulfur coal.
More advanced technology suitable for new plants would
not be widely available within the ten year time limit.
This proposal implies a proportionate reduction of acid sulfate
deposition.
Using atmospheric models, FGG (1983) estimate that a
proportionate sulfate deposition reduction would indeed be expected in
the Adirondacks, an environmentally sensitive area.
But because nitric
oxide emissions would not be reduced, the expected average increase of
rain pH would be less than 0.2 units to pH 4.3-4.4.
In contrast, a
report of the National Research Council (NRC, 1981) recommended that a
desirable average precipitation pH would be 4.6-4.7.
Such levels could
only be achieved by almost complete elimination of sulfur emissions, or
by substantial curtailment of both sulfur and nitrogen emissions.
Since
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6
the Mitchell bill does not explicitly suggest a goal for the amount of
reduction of acid deposition, it is not clear what the proposers expect
regarding environmental improvements following the mandated sulfur
emission reductions.
These reductions are by no means inexpensive.
Various estimates place the annual costs of the Mitchell bill in the
range of $3 to $8 billion (Friedman, 1981; FGG, 1983).
4. RELATING EMISSIONS TO DEPOSITION
The ultimate goal of any acid rain mitigation strategy is the
reduction or elimination of the ecological impact of acid deposition its effects on aquatic systems, forest crop productivity, potable water
supply systems and materials damage.
But these adverse effects are
mostly confined to the so-called sensitive areas and are most prominent
in the very northeastern corner of the U.S. and eastern Canada.
A better
measure of the efficacy of any strategy would be the reduction of
deposition achieved in sensitive areas rather than the aggregate
reduction of emissions.
A receptor-oriented strategy requires the setting of a goal for the
reduction of acid deposition in sensitive areas.
Such a reduction would
be based on an acid deposition standard which would ensure that long term
environmental damage will not occur.
The relationship between acid
deposition and ecological changes are presently not well defined.
Recent
surveys indicate, however, that a minimum annual rate of deposition of
acid sulfate can be used as a criterion for protection of sensitive
ecosystems from further damage (NRC, 1981; NRC-Canada, 1981; Stockholm,
1982).
Deposition reduction goals for all sensitive areas can then be
constructed by tailoring emission reductions to meet this criterion.
Tailoring emission reductions to achieve maximum environmental
benefits of acid deposition reductions requires the use of
source-receptor relationships derived from meteorological models.
These
models confirm the intuitive concept that acid deposition at a receptor
site is more affected by a nearby source than by a distant source of
equal strength.*
Long range transport models provide a quantitative
measure of the relative contributions of nearby and distant sources to
local acid deposition.
At present, atmospheric models are not recognized
by all experts as valid policy tools for emission reduction allocations
(NRC, 1983).
Our analysis showed that in regard to annual average
airborne sulfate concentrations there is substantial agreement between
eight models used by the U.S.-Canadian Work Group on Transboundary Air
Pollution (Fay, 1983).
Further model improvements and the incorporation
of NOx chemistry should strengthen the basis of using atmospheric
models for allocating emission reductions in the source areas.
5.
ALTERNATIVE ACID DEPOSITION CONTROL STRATEGIES
We now turn to the question of how emission reductions, however
allocated, can be accomplished.
For existing sources, the technological
alternatives are (1) removal of sulfur from the fuel before combustion;
(2) removal of sulfur during combustion; (3) the substitution of low
sulfur for high sulfur fuel, and (4) the removal of sulfur dioxide from
flue gases.
Techniques for removing sulfur during the combustion process
(e.g., fluidized bed combustion, FBC, lime injected multistage burner,
*It should be noted that the progressively lessening influence of
distant sources by no means implies that acid deposition at a specific
receptor is all caused by local (e.g., intra-state sources). The scale
length of acT deposition is a few hundred kilometers.
8
LIMB) are not yet fully developed for large scale commercial use and
would require replacement of the steam generator, a major component of an
electric power plant.
Thus, it is doubtful that existing sources can be
modified in time to utilize these novel methods.
Removing sulfur from the flue gases by scrubbing requires a
substantial add-on facility to existing plants, called retrofit.
Not all
plants can be so modified for lack of space and waste stream disposal
area.
Other modifications to fuel handling and flue gas processing
systems (e.g., fly ash precipitators) may also be needed.
While
certainly not universal panaceas at present, scrubbers are perhaps the
most widely applicable to existing facilities.
Modern utility and industrial boilers are designed to use a specific
fuel type.
For example, it is not possible to burn gas efficiently in a
boiler designed for coal.
Even substitution of low for high sulfur coal
would require modifications to the coal handling equipment and the
electrostatic precipitators.
While it is possible to consider the
replacement of high sulfur by low sulfur fuels, the potential for such
substitution and the costs (both average and marginal) will depend on the
myriad difficulties to be surmounted in a large number of nonidentical
plants.
It will not be simple to implement a control strategy which
induces many users to change fuel type.
Because of the variable effects on sensitive areas of nearby and
distant sources, there are other management schemes that could lessen the
deposition in sensitive areas.
Emissions could be shifted to more
distant locations by importing electric power to the source areas.
This
could be accomplished either by use of surplus generating capacity in the
more remote regions or by constructing new or replacement plants for
9
export of power to the source areas.
An interchange of low and high
sulfur fuels between proximate and more remote areas would also move
sulfur emissions further away from sensitive areas.
the least-emission-dispatch (LED) method.
Finally, one may use
When decreased acid deposition
is desired, e.g., during high pollution episodes, the electric generating
plants with highest emissions could curtail output or shut down
completely while those with lesser emissions (e.g., oil- and gas-fired
power plants) take over the excess load.
Of course, it is not at all
certain that such measures would be less costly than reducing emissions
from present sources by use of emission control technology, but they do
provide some potential for reducing deposition beyond the recourse to
installing elaborate equipment.
There are potential environmental and economic benefits if emission
reductions were timed to the season of the year and possibly even to the
appearance of high pollution episodes.
Observations of the seasonal
patterns of acid deposition show that sulfate deposition is much more
pronounced during the summer half of the year.
The use of low sulfur
(and generally expensive) fuels during these times would still be less
costly than their year-round use, or installation of emission control
technology.
Another summer phenomenon is the persistent elevated
pollution episode in which acidic and other atmospheric contaminants
build up to high levels whereupon they are scavenged by rain, resulting
in a highly acidic rainfall.
If such events could be forecast, the use
of clean fuel just prior to and during such episodes might reduce the
large increments of deposition.
Any substantial reduction of sulfur emissions, whether that
contemplated by current legislative proposals or the suggested
10
alternative schemes, will require about ten to twenty years for complete
implementation.
Limitations on the productive capacity of equipment
suppliers and on capital markets to provide financing mean that changes
will have to be phased in over a period of years if costs are to be
contained.
Planning and execution of major modifications to a large
source require several years.
In order to secure the most immediate
environmental benefits, modifications to facilities in the source area of
the primary impacted areas should receive first priority.
Over a long period of time - perhaps thirty years or more - a
significant reduction of sulfur and nitrogen emissions below present
levels would result from the replacement of existing plants or combustion
systems by new ones which would have to meet new source performance
standards (NSPS).
Even with some growth in fuel usage in the eastern
U.S., aggregate sulfur and nitrogen emissions should decrease because the
NSPS emission standards are considerably more stringent than the average
present emission levels.
On a shorter time scale - ten to twenty years -
the emission reduction must be exacted from existing sources.
6. POLICY IMPLICATIONS OF ALTERNATIVE STRATEGIES
Emission-oriented acid rain control proposals, such as the Mitchell
bill, would set a more-or-less uniform sulfur emission standard (e.g.,
1.2 Ib SO2 per million BTU) which is less stringent than the NSPS
standard.
This approach is consistent with the principles of the Clean
Air Act in that it establishes a uniform emission standard throughout the
country.
Such a policy supports the protection of regional air (and
rain) quality irrespective of local air quality regulations.
Uniform
emission standards would prevent individual states from allowing
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excessive emissions and thereby gaining a competitive advantage over
other states whose regulations may be more stringent.
By linking sulfur
emissions to fuel heat value, the Mitchell bill departs in detail from
the NSPS goal, which requires the use of sulfur removal technology even
for low sulfur fuel.
Nevertheless, the emphasis on interstate uniformity
of specific emission rates is consistent with historical precedents.
The Mitchell bill incorporates some flexibility.
Neighboring states
may trade emission reductions provided the aggregate emissions are not
increased.
Such variation is also recognized under the current "bubble"
concept. Within a given plant or airshed, emissions may be increased
above applicable emission standards from some sources provided they are
reduced by other sources and the aggregate levels are not increased.
The
objective of such a policy is to permit less costly ways of controlling
aggregate amounts of emissions, with the assumption that the
redistribution of emissions does not deleteriously affect air quality.
What we know about acid rain calls into question the efficacy of
these traditional policies.
How the reductions of sulfur emissions are
distributed within the "bubble" encompassing the eastern U.S. (and
Canada) very much influences the environmental benefit of specific
sensitive areas.
Environmental effects are not indifferent to the way
aggregate emissions are parceled out.
Although it is true that uniform
emission standards would temper interstate competition to exploit local
variations in emission standards, there is sufficient reason to consider
more appropriate policies for acid rain mitigation than uniform
standards.
A uniform emission standard is not likely to lead to a
least-cost policy for controlling acid rain deposition in sensitive
areas.
Where aggregate costs may become very large - which is very
12
likely for any acid rain control policy - the savings to be realized in a
targeted approach may be quite substantial.
Emission reduction strategies tailored to achieve desired deposition
reduction in sensitive areas must still employ suitable criteria for
allocating reductions.
Two criteria are suggested:
cost and equity.
If
aggregate costs are minimized for a given level of net deposition, then
source reduction will be allocated to a level where the marginal cost of
deposition reduction will be the same for all sources.
This implies a
greater marginal cost of emission reduction for nearby sources compared
with distant sources.
On the other hand, an equity principle might be
invoked such as equal deposition per unit of fuel heat for all sources
(e.g., FGG,
1983).
A receptor-oriented strategy which minimizes acid deposition in
sensitive areas may impose higher marginal (and average) costs of sulfur
emission reduction on sources closer to sensitive areas, as mentioned
above.
Because marginal costs increase with the level of emission
reduction at any source, more stringent and expensive control will be
needed near sensitive areas than at more distant locations.
Although no
detailed analysis has been made, it seems likely that the increments in
the cost of electric power and industrial heat which will result from the
implementation of such a strategy will be greatest for those sources
proximate to sensitive areas, and certainly greater than would be imposed
by a uniform emission reduction policy.
Thus, while aggregate costs for
the region (or nation) would be less for a receptor-oriented stratetgy,
some sources may experience larger costs.
Given the unique nature of the acid rain problem, it may be necessary
to modify the traditional policy of requiring each polluter to bear the
13
full costs of his own abatement.
The allocation of emission reduction
which would minimize aggregate costs would require very stringent and
expensive control systems for sources near sensitive areas.
It has been
suggested that a trust fund financed by a regional or national tax on the
consumption of electric power could underwrite all or part of the capital
costs of control equipment retrofitted to existing plants for the purpose
of meeting the allocation requirements (Parker, 1983).
An alternative
source of trust funds would be a sulfur emissions tax which would have
the added benefit of providing an incentive to reduce emissions as well
as a recompense for operating costs if only capital costs are to be paid
from the trust fund.
Even though it may not be entirely equitable, a
trust fund may be a practical necessity, considering the substantial
costs any acid rain mitigating strategy will entail.
Reducing emissions by replacing eastern high sulfur coal with western
low sulfur coal would have significant economic, social and political
ramifications.
Loss of employment and production in eastern high sulfur
coal mines would add considerably to the burden of communities already
impacted by the decline of smokestack industries.
On a national scale,
there would probably be a net loss of mining employment and perhaps total
employment.
Eastern coal mining states will oppose the export of mining
activity to western states because of the adverse local economic and
social impacts.
The infrastructure improvements required for such a
shift and the possibly smaller increase of electricity cost compared with
other alternatives for emission reduction will be seen in these states as
not compensating in amount or kind the loss of coal mine production.
14
7.
TRANSBOUNDARY ACID RAIN PROBLEMS
A major element of the U.S. acid rain problem is the Canadian view
that acid rain precursors emitted from U.S. sources drift across the
U.S.-Canada border and contribute to acid deposition in southeastern
Canada, an ecologically sensitive area.
Damage to Canadian lakes and
forests could have a significant economic impact in these provinces.
While not denying a similar effect in the U.S. from Canadian sources,
Canada is urging prompt action for reducing sulfur emissions throughout
eastern North America.
The cumulative observations of acid rain damage to aquatic systems in
the northeastern U.S. and southeastern Canada and the realization that
the sources of acid rain precursors could be quite distant from the
border (and on both sides) created the need for international
consultation on methods for control of acid precipitation.
In June 1978,
an exchange of notes created the U.S.-Canada Research Consultation Group
on Long Range Transport of Air Pollutants.
This was followed in 1979 by
a Joint Statement on Transboundary Air Quality which expressed the
determination to reduce transboundary air pollution and to seek bilateral
agreements on control measures.
A year later a Memorandum of Intent
(MOI) was agreed upon, detailing plans for further negotiations and the
exchange of scientific and technical information, principally on the
problem of acid rain.
A Coordinating Conmittee was established and
scientific Work Groups were appointed to assist the Coordinating
Committee (Maclure, 1983).
The "export" of acid rain precursors appears to be more detrimental
to Canada than the U.S.
According to one estimate (Galloway and
Whelpdale, 1980), 14% of U.S. sulfur emissions flow into Canada while 33%
15
of Canadian emissions flow in the reverse direction.
But because U.S.
sulfur emissions are seven times those of Canada, the flow into Canada is
three times the reverse flow into the' U.S.
At the present time there is
no estimate for the respective rates of acid deposition due to the
transboundary flows of precursors.
If these estimates are correct, then the "import" of acid sulfate to
Canada is 75% of Canadian emissions (the comparable U.S. import is 6%).
Even though deposition ratios may be different than transboundary flows,
it is clear that Canada cannot greatly ameliorate its acid rain problem
without a substantial U.S. effort of curbing sulfur emissions.
But with
respect to environmentally sensitive areas in upstate New York and New
England, the U.S. would noticeably benefit from Canadian emission control.
One study (Environment Canada, 1981) estimates that 30% of acid sulfate
deposition at an Adirondack receptor is caused by Canadian sources. On
the other hand, a joint U.S./Canadian emission control scheme targeted
toward the protection of northern New York and New England would also
benefit the sensitive areas in southeastern Canada.
The Canadian
sensitive receptors lay in the "lee," so to speak, of the U.S. receptors
in regard to the prevailing acidity-bearing air trajectories.
These studies indicate that the transboundary flows of precursors and
the acid deposition component due to precursor imports are significant
factors in the evaluation by each country of the expected benefits from
emission control programs.
Certainly for Canada and possibly for the
U.S., an acid rain mitigation strategy which is not mirrored on the other
side of the border will not be fully effective.
But more important to
future U.S.-Canada negotiations will be an acceptance of estimates of
source-receptor relationships as the basis for an equitable distribution
of emission reductions on both sides of the border.
8. CONCLUSIONS
.I
Given the very substantial cost of any significant reduction of
emissions of acid rain precursors, an efficient national acid rain
control policy should be receptor- rather than emission-oriented.
Such a
policy is likely to be less expensive and would benefit the impacted
areas to a greater degree.
It would concentrate the emission reduction
in those source areas that deliver the bulk of acid deposition to the
environmentally sensitive regions.
In contrast, the traditional policies
of uniform emission standards across the nation, as exemplified by
proposed acid rain legislation, are likely to be more costly and less
effective.
In addition, a receptor-oriented policy could produce more
immediate results in reducing acid deposition than the long period (one
to two decades) required for implementation of a uniform emission
reduction program.
A limited receptor-oriented approach would also
permit a timely appraisal of its success (such as a measurable reduction
of wet ion deposition at the selected receptor) before vast expenditures
are sunk into a uniform source-oriented approach.
To secure the savings inherent in a receptor-oriented policy, a
variety of emission control technologies and management alternatives must
be evaluated on a source-by-source basis.
In addition to the standard
techniques of fuel cleaning, flue gas scrubbing and combustion
modification, other possibilities, such as seasonal and episodic fuel
substitution, least emission dispatch and electricity import should be
considered in arriving at a least cost emission reduction scheme.
The proximity of some environmentally sensitive areas in the U.S.,
such as northern New York and New England, to equally sensitive areas in
Canada provides a basis for a mutually reinforcing receptor-oriented
17
strategy in both countries., The mutual benefits of targeting emission
reductions in source areas adjoining the international border could
become a strong incentive for reaching an international agreement on this
important transboundary pollution problem.
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18
REFERENCES
Congressional Record, Senate, 1983, "Description of Acid Rain Legislation
Introduced by Senator George J. Mitchell," Washington, DC 20510.
Environment Canada, 1981, "Impact Assessment of Acid Deposition," Interim
Report, Ottawa, Canada, KIAICB.
Fay, J.A., 1983, "Long Range Transport of Acid Rain Precursors," MIT
Energy Laboratory, Cambridge, MA 02139, MIT-EL 83-005.
Fay, J.A., Golomb, D. and Gruhl, J. (FGG), 1983, "Controlling Acid Rain,"
MIT Energy Laboratory, Cambridge, MA 02139, MIT-EL 83-004.
Friedman, R.M., 1981, "Testimony before the Senate Committee on
Environment and Public Works--Proposed Legislation (S. 1706 and S. 1709)
Related to Acid Precipitation Control," Office of Technology Assessment,
U.S. Congress, Washington, DC 20510.
Galloway, J.N. and Whelpdale, D.M., 1980, "Atmospheric Sulfur Budget for
Eastern North America," Atmospheric Environment, 14, 409-417.
Golomb, D., 1983, "Acid Deposition - Precursor Emission Relationship in
the Northeastern U.S.: The Effectiveness of Regional Emission
Reduction," Atmospheric Environment, 17, 1387-1390.
Maclure, J., 1983, "North American Acid Rain and International Law,"
Fletcher Forum, 121-154.
MAP3S/RAINE, 1982, "The MAP3S/RAINE Precipitation Chemistry Network:
Statistical Overview for the Period 1976-1980," Atmospheric Environment,
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National Research Council, NRC-Canada, 1981, "Acidification in the
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National Research Council, NRC-U.S., 1981, "Atmosphere-Biosphere
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Consequences of Fossil Fuel Combustion," Washington DC 20418.
National Research Council, NRC-U.S., 1983, "Acid Deposition, Atmospheric
Processes in Eastern North America," National Academy Press, Washington,
DC 20418.
Parker, L.B., 1983, "Distributing Acid Rain Mitigation Costs: Analysis
of a 3 Mill User Fee on Fossil Fuel Electricity Generation,"
Congressional Research Service, Library of Congress, Washington, DC
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Stockholm, 1982, Conference on Acidification of the Environment, Report
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