2010 Progress Report - International Joint Commission

y 2007 the regions receiving greater than 15 kg/ha/yr
of nitrate wet deposition had all but disappeared in
the two countries, with the exception of small areas
of Pennsylvania, New York and Ontario.
Wet deposition measurements in Canada are
made by the federal Canadian Air and Precipitation
Monitoring Network (CAPMoN) and networks
in a number of provinces/territories, including
Alberta, the Northwest Territories, Quebec,
New Brunswick and Nova Scotia. Dry deposition
estimates are made at a subset of CAPMoN sites
using combined air concentration measurements
and modeled dry deposition velocities—the socalled
inferential technique. In the United States,
wet deposition measurements are made by two
coordinated networks: the National Atmospheric
Deposition Program/National Trends Network
(NADP/NTN), which is a collaboration of federal,
state and nongovernmental organizations
(http://nadp.sws.uiuc.edu/), and the NADP/
Atmospheric Integrated Research Monitoring
Network (AIRMoN), which is a sub-network of NADP
funded by the National Oceanic and Atmospheric
Administration (http://nadp.sws.uiuc.edu/AIRMoN/).
Dry deposition estimates in the United States are
made using the inferential technique based on
modeled dry deposition velocities and ambient air
concentration data collected by EPA, the National
Park Service (NPS), and the Clean Air Status and
Trends Network (CASTNET) (www.epa.gov/castnet).
Wet deposition measurements in the United States
and Canada are comparable, and the data are
available from the websites of the individual
networks and from a binational database accessible
to the public at www.msc-smc.ec.gc.ca/natchem/
index_e.html.
However, contrary to wet deposition estimates, the
comparability of dry deposition velocities calculated
by the Canadian and U.S. models is poor, although
comparability between the measured air concentration
values is reasonable. Studies show that dry deposition
can be an important contributor to total deposition;
thus ongoing efforts are in place to study the sources
of the differences between the modelled dry deposition
values. At the Borden research station in Ontario,
instruments have been co-located for a number of
years as part of an ongoing bilateral inter-comparison
study on modelling dry deposition. Recent studies
attempt to quantify the sensitivity of both the CAPMoN
and CASTNET dry deposition models to a variety
of factors that infl uence the dry deposition velocity,
with the goal of refi ning model parameters for better
comparability in future measurements, and reconciling
past measurements.
Commitments
Preventing Air Quality Deterioration and Protecting Visibility
Canada is addressing the commitment
to prevent air quality deterioration and
ensure visibility protection by implementing
the Canadian Environmental Assessment
Act, the Canadian Environmental
Protection Act, 1999 (CEPA 1999), and the
continuous improvement (CI) and keeping clean
areas clean (KCAC) principles that are part of the
Canada-wide Standards for Particulate Matter (PM)
and Ozone.
CANADA
Federal and provincial environmental assessment
regulation requires that air quality be considered
for all major new point sources or modifi cations to
existing sources to ensure that Canadian objectives to
protect the environment and human health are met.
Mandatory provincial reporting processes require new
and existing sources to fi le notifi cations, which are
reviewed to determine the scale of the environmental
assessment appropriate to each case. CEPA 1999
prefers to use pollution prevention in its approach
to environmental protection. Implementing similar
principles—pollution prevention, CI and KCAC—is
also part of the Canada-wide Standards (CWS).
There are numerous locations across Canada where
ambient levels of PM and ozone are below the CWS.
Actions are required to ensure that levels in these
areas do not rise to the CWS, but rather, are reduced
over time, and that clean areas are maintained. For
example, although Metro Vancouver experiences good
regional air quality relative to most other Canadian
urban areas, the region adopted an Air Quality
Management Plan (AQMP) in 2005 to maintain and
11