Background
The Western Regional Air
Partnership (WRAP)
and Central Regional Air Planning Association
(CENRAP) are two of five Regional Planning
Organizations (RPOs) that have been created to evaluate, determine methods to
improve, and track improvements in regional haze at sensitive locations within
their jurisdictions. RPOs are newly-defined entities that intend to respond to
the transport of visibility-reducing pollutants within and across state and
international boundaries. RPOs need to assess current haze conditions, establish
baseline levels, specify and coordinate emissions reduction strategies, and
evaluate the effectiveness of those strategies for the coming six decades. The
goal is to achieve “natural” visibility conditions by 2065. Quantifying
“natural” visibility levels beyond the defaults offered by U.S. EPA will be one
of the major challenges faced by RPOs during its lifetime. Identifying the
emissions sources causing excessive haze levels and determining where and when
emissions reductions are needed to make reasonable progress is another major
challenge.
The WRAP has formulated
specific questions the answers to which will aid in the execution of its
responsibilities. These questions are to be answered by the application of
different data analysis methods to existing data sets. These analyses are
independent of regional dispersion modeling and will help to form the conceptual
models on which the regional models are based. Data analyses are intended to be
interactive, with products made available on the internet as they are completed.
This will facilitate feedback on and refinement of the results and presentation
methods. The same question may be addressed several times, using different data
analysis methods and data bases, to reduce uncertainties and to elucidate
phenomena discovered in prior analyses. Answers to questions will be provided
for every WRAP and CENRAP class I area represented by an IMPROVE site as well as CENRAP and tribal IMPROVE protocol sites that tracks haze
levels. In some cases these will be site specific, while in
other cases the answers will apply to sub-regions that are shown to be affected
by the same emission sources and meteorology.
Project Goals and Objectives
The goal of the work is to answer questions about the chemical components that
cause regional haze, relationships of haze to meteorology, the emissions that
cause haze, and the effects of previous and future emissions reductions on the
poorest and best visibility levels. Specific objectives are to:
1. Provide answers to specific questions for each western
class I area using
several independent data analysis approaches and available data sets.
2. Evaluate the uncertainty and generality of these answers by
quantitative
error analysis, comparison of results from different approaches, and informed
judgment.
3. Integrate and present results in concise and understandable language that can
be used to support WRAP evaluation of and justification for actions that improve
western visibility.
4. Post results on the COHA web site
Available Databases
Multiple databases have been archived for use in the descriptive data analysis.
These databases will be used to identify emission sources as well as the
precursors of haze particles, to characterize the physical setting for use in
meteorological data analysis and to identify existing environmental monitoring
networks to help in the data analysis.
Assessment Methods
NARSTO (2002)
describe a variety of assessment methods applicable to determining the causes of
haze. Several of these are briefly summarized below. These descriptions will be
referenced in the subsequent task statements.
Technical Approach
One or more projects are described for each secondary question specified in the
RFP. Each project will result in a written document that includes a brief review
of what is already known from the region (determined from prior reports and
publications), a description of the method applied and the data used, results of
the assessment, an evaluation of uncertainties, conclusions, and recommendations
for follow-up assessment. Supplemental data, tables, and plots will be
summarized and made electronically available on the COHA web site for more
specific examination and display.