1.1	Introduction

Over the past several years, the International Air Quality Advisory Board (IAQAB) has been concerned with all aspects of air pollution on both sides of the US-Canada border that have an impact on transboundary pollution transfer. Topics considered include the control of ozone and fine particulate (PM _2.5 ) formation; acid rain emissions and deposition; mobile source emissions from vehicles of all types; emissions of persistent toxic substances and the possible impact of global climate change. The evolution of air pollution standards in both countries has also been traced by the Board .

This report emphasizes the complexity of many of the air pollution issues that exist on both sides of the border, and the continuing adjustments and changes that will be required if the transboundary transfer of air pollutants is to be reduced. Several recommendations are put forward by the Board for consideration by the International Joint Commission.

The Board has also completed more detailed work on the emissions, transport and deposition of dioxin to the Great Lakes basin, while cataloguing emissions and control efforts applied to other persistent toxic substances under Annex 15 of the Great Lakes Water Quality Agreement. This work can be viewed on the IAQAB website at http://www.ijc.org/rel/boards/iaqab/index.htm. A printed report, describing the transport and deposition modeling effort as one of the 1997/99 Great Lakes Priority activities, can be obtained from the IJC Great Lakes Regional Office.

1.2.1

Ozone and Particulate Matter

Among the significant developments since Progress Report 24 is the beginning of negotiations on an Ozone Annex under the Canada/United States Air Quality Agreement. At a recent first meeting, representatives of the United States and Canada agreed to work toward a signed agreement by the end of the year. The Board will track subsequent negotiations over the next several months and advise the Commission as appropriate.

The development of Canada-wide Standards for ozone and fine particulate by the federal and provincial environment ministers, scheduled for completion by June of 2000, is reviewed and the Board recommends the Commission encourage the Canadian Council of Ministers of the Environment (CCME) to adopt, during this year, a Canada-wide Standard for ozone of 65 ppb, 8 hour average, to be attained no later than the year 2010.

An update on the evolving issues of comparability of fine particulate measurements taken using the US Federal Reference Method and those obtained by the different prevailing Canadian protocol is also provided.

Developments with regard to revised standards for ozone and fine particulate in the United States are also described, particularly the impact of recent Federal Court decisions remanding these standards. In view of the court action, the United States Environmental Protection Agency (USEPA) has proposed reinstatement of the 1 hour ozone standard in nearly 3,000 counties. The agency will also be requesting that 10 major urban centers revise their smog reduction plans.

1.2.2

Acid Gas Emissions (SO 2 and NO x )

Commitments by both countries to reduce acid rain emissions are reviewed. With respect to stationary sources, the focus is on emissions from utilities. The USEPA action, supported by some states and the Province of Ontario, against 'grandfathered' coal fired utilities excluded from upgrades in emission control systems in the Clean Air Act Amendments of 1970 and 1977 is reviewed, as is the status of the USEPA NO _X State Implementation Plan call, which recently withstood a challenge in Federal court by a number of states. The Agency response to petitions under Section 126 of the US Clean Air Act from downwind (largely New England) states against acid gas emissions in several upwind states is also summarized.

The Ontario Strategic Attack on Air Pollution is also reviewed, and summarized in Table 1. The Province is proposing to cap NO (not NO _X ) emissions from oil and coal fired utilities at 36 kilotonnes per year by 2001 ( from the current cap of 38 kt/year) and an SO ₂ emissions cap at 157.5 kt/yr by the year 2001 (from 175 kt/year currently). Emissions Performance Standards (in kg per megawatt for NO and SO ₂ ) are proposed for individual oil and coal fired facilities. Those for nitrogen species do not appear as aggressive as the benchmark used by the USEPA for such facilities. An emissions trading system for these gases is also proposed. The Board will track this development to determine how this trading system for SO ₂ and NO _x will consider limits on the distance and direction of sources participating in trades and, with regard to NO _x emissions, what additional actions outside the trading processes are proposed to deal with seasonal variability and the amelioration of short term episodes.

With respect to the Ontario Strategic Attack on Air Pollution, the Commission should seek the following enhancements:

1. the inclusion of gas fired units within any nitrogen oxides cap for Ontario electrical generation facilities;
2. rather than the current cap of 36 kt/year on NO emissions, a commitment to a lower cap of 21.6 kilotonnes/year from all combustion electrical generation facilities consistent with application of the USEPA NO ₂ performance benchmark for such facilities of 0.15 lb of NO ₂ /mmBTU (0.65 kg/MWh);
3. an acceleration of the province-wide, multi-sectoral programs for SO ₂ , NO _X , and VOCs to an attainment year of not later than 2010, with ongoing and careful review to determine if reduction actions are adequate to meet air quality objectives; and,
4. assurances that the use of emissions trading not allow total SO ₂ and NO _X emissions to exceed the province-wide targets established by Ontario.

The new US Tier 2 mobile source standards, including reductions in sulfur in gasoline and emissions of SO ₂ , NO _X and particulate matter are reviewed. The projected impact of NO _X controls on mobile sources over the next several years is shown in Table 2. The Canadian government will promulgate comparable standards within the same timeframe with attainment in 2007. The US sulphur in gasoline standard is comparable to the current Canadian regulation.

The Board draws particular attention to the human health effects of fine particulate emissions from diesel engines , especially the issue of carcinogen risk. It notes that improved particulate emission control technology will require reductions in sulphur fuel content, similar to those recently required in gasoline, and concludes that the Commission should recommend that the governments of the United States and Canada move to adopt standards limiting the sulphur content of diesel fuel, so as to enable the introduction of advanced, reliable and durable high level control systems for NO _X and particulate matter on diesel engines. These sulphur standards will likely lead to a diesel fuel with an estimated 5 ppm sulphur content. The infrastructure to produce and deliver this fuel must be place in the year 2006 to support emission standards applicable to the 2007 model year vehicles.

1.2.3

Climate Change

Further detail on measured phenomena and possible impacts of climate change are examined in some detail, along with a few possible mechanisms for various countries to meet their commitments to green house gas reductions under the Kyoto Protocol. The emergence of a market for trading in greenhouse gas emissions and the involvement of the World Bank in such efforts are also described.

1.2.4

Toxic and Persistent Toxic Substances

The Board also considers the issue of toxic and persistent toxic emissions and releases . It notes that the newly enacted requirement for US utilities to report on toxic emissions under the Toxics Reduction Inventory (TRI) will make that sector the most significant source of total toxic substances released. Emissions of mercury , a persistent toxic substance, from sources in United States and Canada are reviewed in some detail. Regarding US sources, consistent with the Board's earlier concern about the effect of deregulation on the utility sector, the focus is on mercury emissions from the coal fired portion of that sector. The Board notes that a multi-pollutant control strategy for mercury, acid gases, fine particulate, and perhaps greenhouse gases, is appropriate for these coal-fired utilities. The activities of the New England Governors/Eastern Canadian Premiers and the recommendations of the Commission for Environmental Cooperation for further control of mercury emissions from utilities are both reviewed.

The Canadian commitment to a proposed Canada-wide Standard for Mercury is noted; objectives for metal smelting and municipal, medical, hazardous waste and sewage sludge incineration are reviewed. A Canada-wide Standard (CWS) for coal fired utilities is being held in abeyance until at least mid 2000. The Board states that the Commission should recommend to the Canadian Council of Ministers of the Environment that data on mercury emissions from individual facilities be made available to the public through the CCME website and other means. If absolutely necessary, provisions could be made for the exclusion of process (not emissions) details from this information due to confidentiality agreements; the rationale for doing so should be described.

The Board also reviews sources of benzene in the United States and Canada, considers the level of this compound in gasoline (typically 1 to 1.5%) and describes the proposed action on benzene under the CWS process.

Data indicating that the uncontrolled residual burning of refuse is a significant source of dioxin and furan and other hazardous contaminants is examined. The Board recommends that the Commission should recommend governments recognize the significant contribution of the backyard open burning of trash to the total burden of dioxin on the Great Lakes system, and ensure that the curtailing of this activity will be integrated into plans and strategies to eliminate loadings of dioxin to the Great Lakes.

Finally, the status of Methyl Tertiary Butyl Ether (MTBE) , an additive used in reformulated gasoline to reduce air pollution, which has been implicated in the fouling of water supplies in several states (Progress Report 24), is discussed. The recent announcement by the USEPA of an intention to 'significantly reduce or eliminate' MTBE use in gasoline is also noted.