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Updated
April 19, 2006 |
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California Regional Particulate
Air Quality Study (CRPAQS) |
Objectives |
| The California
Regional PM10/PM2.5 Air Quality Study is a comprehensive
public/private sector collaborative program with two
main goals:
- to provide an improved
understanding of particulate matter and visibility
in central California, and
- to provide decision-makers
with the tools needed to identify equitable and efficient
control methods.
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| Background |
| The study
is intended to evaluate both the national and State
air quality standards for particulate matter smaller
than 10 micrometers in diameter (PM10) and for particulate
matter smaller than 2.5 micrometers (PM2.5). Both these
standards are consistently exceeded in central California,
compromising the health of more than 10 million people.
Excess particulate matter reduces visibility, affects
crop yields, causes materials damage, and adversely
impacts the overall quality of life. |
The study has
involved extensive planning and preparatory research,
including:
- literature review of
previous studies,
- development of conceptual
models for episode behavior,
- a multi-year assessment
of agricultural practice contributions to particulate
emissions,
- a preliminary field
monitoring program, the 1995 Integrated Monitoring
Study (IMS95), to understand high particulate episodes
and evaluate monitoring equipment and data collection
needs,
- analysis and modeling
of historic and IMS95 data, and
- development and improvements
to the emissions inventory.
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| Field
Study |
A field
study was designed to address annual particulate levels
as well as fall and winter episodic conditions. Data
was collected for 14 months (December 1999 through February
2001) throughout the San Joaquin Valley (SJV) and surrounding
regions. Enhancements included short-term, intensive
monitoring during the fall and winter, when PM concentrations
are highest, and during the summer, complemented by
data obtained from the Central California Ozone Study
(CCOS). Key components included:
- Sampling Locations
- the backbone of the annual monitoring used the existing
PM10 network, as well as new PM2.5 networks established
by the ARB and local air pollution control districts.
Over 70 PM10 sites and 50 PM2.5 sites comprised this
backbone network. Enhancements for the study included
full scale “anchor” monitoring sites which measured
gaseous and aerosol species, through both filter-based
and continuous species specific methods. In addition,
“satellite” monitoring sites measured aerosol species
using portable PM monitors and nephelometers. Surface
and aloft meteorological measurements were collected
utilizing a network of surface meteorological sites,
radar profilers, and sodars. A special 100-meter tower
collected additional meteorological and air quality
data at several elevations.
- Fall
Program - took place in the central
portion of the San Joaquin Valley in October and November
of 2000, corresponding to periods of historically
high PM10 concentrations dominated by geological material.
Specific issues addressed included identification
of the sources of geological material, determination
of their zone of influence, and development of improved
data on dust suspension and deposition. The fall program
included neighborhood-scale saturation monitoring
as well as measurement of organic species and particle
morphology.
- Winter
Program - took place December 2000 through
February 2001. PM2.5 concentrations are historically
highest during the winter months, dominated by secondary
ammonium nitrate and carbonaceous material. Specific
issues addressed included identification of the sources
of carbonaceous material, determination of the limiting
precursors for secondary PM species, surface and aloft
transport and mixing mechanisms under low wind speed
conditions, and the zone of influence of both primary
and secondary sources of PM. The winter program also
included an expanded set of anchor sites, and an enhanced
upper-air monitoring network. On days forecast to
have the highest PM concentrations, additional measurements
were taken, including organic species tracers, fog
chemistry, time-of-flight mass spectrometry, and wet
deposition. Special emphasis was placed on collection
of continuous and species-specific particulate measurements
to support both receptor and grid-based modeling.
Methods for collecting information aloft included
use of the 100-meter tower, an elevated site in the
Sierra Nevada mountains, and a remotely piloted blimp,
which has been specially designed to fly under low
visibility, stagnant conditions.
- Source/Emissions
Inventory Data
- Episode specific
and enhanced emission inventory estimation data were
also collected. Several projects were targeted at
collecting improved information for transportation
sources, including development of updated chemical
speciation profiles, and vehicle traffic counts. Other
emissions projects include development of a GIS-based
ammonia inventory, and collection of day-specific
emissions. A comprehensive emissions inventory for
the region is being developed to complement the field
measurements.
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| Management |
| The
Study is directed by the same Policy Committee that
managed the highly successful 1990 San Joaquin Valley
Ozone Study (SARMAP Ozone
Study). The San Joaquin Valley Ozone Study
was a landmark example of collaborative environmental
management. The proven methods and teamwork established
in the Ozone Study will
provide a solid foundation for the PM10/PM2.5 program.
The budget for
the CRPAQS is $27.5 million. Funding is provided
through a cooperative partnership between the public
and private sectors (See Study Sponsors). |
| Schedule |
The Concept
for the Study was initiated in 1991 by the agricultural
community when they approached the United States Environmental
Protection Agency (EPA) for funding. Government
entities and industries endorsed the Study, and full-scale
planning began in 1992. Large-scale field monitoring
programs are conducted in from 1999 through 2001, with
completion of the project anticipated in 2005. |
| Study
Output |
| The
Study is intended to provide products to support the
development of effective PM10 and PM2.5 attainment plans
for Central California. It is uniquely positioned
to produce needed data within the implementation schedule
specified for the new PM standards.
The information
developed will allow apportionment of high PM10 and
PM2.5 concentrations to contributing sources, thereby
avoiding burdens on the regulated community from unnecessary
or ineffective control requirements. Implementation
of the control plans that are derived from CRPAQS information,
will result in significant improvements in visibility,
and the health and well-being of the citizens of Central
California.
The methods and
tools for monitoring, emission estimation, control methods
evaluation, and atmospheric modeling that are developed
by the Study can be used outside of California.
The San Joaquin Valley Ozone Study produced numerous
products that advanced the state-of-the-science throughout
the United States. For example, the modeling system
developed under the Ozone study has been distributed
to 20 organizations nationwide. In a similar manner,
it is anticipated that greater than 50 percent of the
CRPAQS funding will result in products with national
significance and transferability.
Take a look at our
CRPAQS presentation
in Microsoft PowerPoint (awma317.ppt - March 17, 1999).
|
Central
California Ozone Study (CCOS) |
| Background |
The Central California
Ozone Study (CCOS) consists of a field program, data
analysis, emission inventory development, and modeling.
The field program of the CCOS was conducted during the
summer of 2000. Emission inventory development, data
analysis and modeling are on-going projects. The entire
effort is expected to be completed by 2011. The California
Air Resources Board (CARB) and local air pollution control
districts plan to use the results of the CCOS to prepare
the demonstration of attainment for the ozone standard
for non-attainment areas in central California. |
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