LONG-TERM MEASUREMENT PLAN

**Vision:** *Develop and Implement an Aerometric Monitoring Network for
Central California to Enhance Effective Air Quality Management for
Criteria Pollutants and Air Toxics and Track Progress Towards Meeting
Regulatory Requirements.*

[Goals:]{.underline} The Technical Committee for the Central California
Ozone Study and the California Regional PM Air Quality Study have been
meeting to develop a proposal for the Policy Committee for a long term
air quality and meteorological (aerometric) monitoring network in
Central California for the goals listed below. The network is intended
to provide data for the criteria pollutants, ozone and particulate
matter, and their precursors, and air toxics, as well as surface and
aloft meteorological data over the long term. This network would fulfil
a void that now exists in the statewide monitoring network, which is
predominantly a compliance network. The major goals for such a network
are fourfold, and are supported by the Technical Committee. These goals
are also recognized in the recently published North American Research
Strategy for Tropospheric Ozone (NARSTO) document, "An Assessment of
Tropospheric Ozone Pollution".

-   Provide capability to model any day: Modeling a single or a small
    number of episodes as the basis for planning does not capture the
    diverse number of episodes (the San Joaquin Valley exceeds the
    federal one hour standard about 40 times per year) that lead to
    exceedances of standards. Thus, reliance on a limited set of
    episodes may not lead to an integrated strategy that will provide
    the most effective guidance to reductions needed to meet that
    standard. A major impediment to modeling more episodes, or even
    modeling a pollutant season is lack of adequate data for input to
    the air quality models, and for evaluation of such models to ensure
    that they are predicting historic concentrations for the right
    reasons. Only with a robust database will there be more confidence
    in attempts at seasonal modeling.

-   Support for ongoing data analysis: While modeling has been the
    primary tool for development of SIPs, the trend is to view modeling
    as one of a number of tools to use in design of an effective
    strategy. Moreover, there is a need to have actual data to see if
    the strategy developed through modeling is actually leading to
    improvements in air quality. Data analysis is the mechanism by which
    to provide both independent corroboration of modeling results of
    historic episodes and to evaluate whether the predicted strategies
    are actually occurring in the real world over time. The lack of
    sufficient data to make this determination in the past has hindered
    our ability to understand whether mid-course corrections were needed
    for SIPs to keep us on track.

-   Develop an integrated strategy for air quality management: Planning
    has been done on a pollutant by pollutant basis. However, the
    precursors for ozone, particulate matter and air toxics are similar
    or the same. Consequently, it makes sense to develop an integrated
    planning process to minimize unintended consequences of a strategy
    for one pollutant adversely affecting a strategy for another. The
    ability to have sufficient data for modeling and analysis is
    critical to development and tracking of an integrated plan.

-   Provide data to support districts, state and federal air quality
    forecasting, smoke management and fire weather efforts. Enhance
    synoptic modeling for these efforts.

[Objectives:]{.underline} In order to fulfil the above goals, the
Technical Committee has defined a set of objectives. These objectives
are designed to meet both regulatory and scientific/technical needs that
should ultimately build more confidence in the air quality management
process in the short and long term. The objectives also help define the
types of analyses needed to provide the relevant information, and
measurements needed for analysis. The major objectives are listed below.
While some objectives are independent of one another, others are
interdependent, and most require similar data:

-   Trends for ozone, particulate matter and air toxics and their
    precursors: Long term monitoring is needed to determine if there is
    a trend, and to be able to quantify the trend. While the present
    network can be used to track criteria pollutants, tracking of
    precursors is inadequate, and has hindered our ability to understand
    the rate of progress or lack thereof to attain standards

-   Population and area exposure: Both state law and good air quality
    management practices require that plans reduce health risk from
    criteria pollutants and air toxics.

-   Emissions reconciliation: Emissions inventory improvement is
    probably the most important issue in the planning process.
    Methodologies continue to improve, but ambient measurements are
    required to allow comparison between emissions models and air
    quality.

-   Mid course evaluation of SIP: With the ability to model more
    episodes, or even a season, better plans should be developed.
    However, aerometric data is needed to determine if the planning
    strategy is actually resulting in predicted reductions before
    regulatory deadlines occur. Mid course evaluation can lead to
    corrections if necessary. This objective was endorsed by the EPA
    workgroups for ozone/PM/regional haze.

-   Transport assessment: The present assessment is dependent on surface
    meteorological measurements and ozone measurements. While it may
    identify transport pathways, it can not describe the related air
    chemistry needed to improve mitigation measures.

-   Forecasting and reporting air quality: Additional data should aid in
    improved forecasting for air quality health advisories and
    agricultural and prescribed burns. Data would also improve synoptic
    scale models that are used for air quality and smoke management
    forecasting.

-   Characterization of chemistry: An understanding of how precursor
    species have changed in response to reduction strategies is needed
    to improve our understanding of ozone and particulate matter
    formation and control.

-   Source-receptor relationships: Improved speciation of precursors
    should, coupled with better profiles of source emissions, allow more
    unambiguous identification of sources that cause and/or contribute
    to high concentrations of criteria pollutants and air toxics.

-   Routine air quality modeling: It is not possible at the present to
    set up and simulate an episode that has recently occurred, yet
    having the ability to do so would enhance the understanding of ozone
    formation for the specific episode and whether strategies developed
    for the SIP would be effective. The envisioned monitoring network,
    along with near real time access to it would allow this type of
    modeling.

-   Surface and aloft meteorology: Many of the identified objectives
    require much more robust collection of surface and aloft winds,
    temperature, and humidity measurements in order to work.

[Monitoring Network:]{.underline} The Technical Committee has developed
a "straw man" network that is based on the identified goals and
objectives (Figures 1 --4). The initial network design would cover the
Bay Area, the Sacramento and San Joaquin Valleys and the surrounding
mountain counties-the primary region encompassed in both CCOS and
CRPAQS. Figure 1 shows the locations of the existing and proposed upper
air meteorological monitoring stations. Figure 2 shows the existing air
quality monitoring stations. Figures 3 and 4 show the existing air
quality monitoring stations and the proposed NOy and VOC measurements,
respectively.

While specific data analysis techniques have not been identified for
this exercise, the Technical Committee is very aware of the different
data analysis methods and techniques that would use the collected
aerometric data from the SARMAP, CCOS, IMS-95 and CRPAQS programs. It is
anticipated that the next iteration of the monitoring network will take
into account the specific needs for individual data analysis methods
into the design so that temporal, spatial, accuracy and precision needs
are explicitly incorporated into the overall design of a monitoring
network.

The cost for implementation and operation of the preliminary network has
not occurred yet. One of the factors in the design of this preliminary
network was that cost would not constrain the design. It is recognized
that start up costs will be in the millions of dollars, and operation of
the network will also be costly. Provisions will need to be made to
provide support for staff and costs for local agencies and the ARB.
However, the anticipated costs for new control strategies and the
benefits in improved health are expected to far outweigh the network
costs. In addition, there appear to be opportunities to leverage some of
the costs with other agency needs and with programs being funded and
being considered for funding through NOAA and the National Weather
Service. Three examples will suffice. First, much effort is being
expended on developing better forecasting tools for both agricultural
and prescribed burns, as required by state law. Many of the objectives
identified above would also serve this need. Second, with the increased
demand for energy, forecasting will become an even more important tool
in maximizing energy usage effectively. Third, NOAA already has
initiated a program to provide much better winter storm forecasts, which
can aid in emergency preparedness activities. As part of this activity,
NOAA is proposed the development of an aloft meteorological network in
coastal and inland California, and this information was presented to the
Technical Committee at their most recent meeting. There appears to be
real synergy between what NOAA is looking at for an extended period, and
the needs elaborated by the Technical Committee in their initial design.
Both groups plan to maintain communications with each other so that we
each can build upon the others plans.

Other areas in which the monitoring network could directly or indirectly
play a major role would be better water resources management and fire
weather forecasting.

[Data analysis:]{.underline} As mentioned above, the prime use of the
data, aside from modeling, will be data analysis to meet the multiple
objectives. Once the analysis methodologies are better defined, costs
can be estimated for doing the analyses. These costs will have to be
factored into the overall cost of the program.

Figure captions:

Figure 1: Existing and proposed upper air meteorological stations. Black
starts show the existing stations. White, yellow and red starts show the
proposed stations in the Bay Area, Sacramento Area and the San Joaquin
Valley, respectively. The locations of the stations are as follow:

*Existing upper air meteorological stations (black stars):*

Livermore, Tracy, Fairfield (Travis Air Force Base), Monterey,
Bruceville, Near Chico (ARB site), Visalia, and Vendenberg Air Force
Base. In addition the National Weather Service makes twice a day
rawinsonde measurements in Oakland (not shown).

*Proposed upper air meteorological stations in the Bay Area (white
starts):*

Point Reyes, San Francisco-Mendocino County corridor, central Bay Area,
South Bay (San Jose), North Bay (Richmond or north of Richmond) and
Delta Region.

*Proposed upper air stations in the Sacramento Area (yellow starts):*

Pleasant Grove, north of Woodland, north of Sutter Buttes, Sloughhose,
Granite Bay and Cool.

*Proposed upper air stations in the San Joaquin Valley (red starts):*

Arvin, west of Modesto, San Luis Reservoir, Chowchilla, Fresno, Huron,
Mouth of Kings River, Tehachapi exit, Carrizo Plain, south west of the
Valley.

Figure 2: Existing air quality monitoring stations. Black starts show
the locations of the existing stations.

Figure 3: Existing air quality monitoring stations and the proposed NOy
measurements. Black starts show the locations of the existing stations.
Green starts show the locations of the PAMS stations where NOy
measurements are proposed to be added. Blue, yellow and orange starts
show the proposed NOy measurements in the Bay Area, Sacramento Area, and
the San Joaquin Valley, respectively.

*PAMS stations:*

Elk Grove-Bruceville, Sacramento-Airport Road, Sacramento-Del Paso,
Folsom-50 Natomas Street, Madera, Clovis Villa, Fresno-1^st^ Street,
Parlier, Bakersfield-Golden State, Arvin, and Shafter.

*Proposed Bay Area NOy measurements:*

Morgan Hill/Gilroy, Labmby Road, Castro Valley, Vallejo, San Jose, Santa
Rosa, Livermore, Bethel Island, Patterson Pass, Creater(?) Peak,

*Proposed San Joaquin Valley NOy measurements:*

Tracy, Modesto, upwind areas of Modesto, downwind areas of Modesto, Kern
Wild Refuge, Early Mart, south east of Elk Hills, east of Stockton, east
of Fresno and east of Bakersfield. The last 3 stations are over
foothills.

*Proposed Sacramento Area NOy measurements:*

Walnut Grove tower, Davis/Dixon, Sloughhouse, north of Woodland, Sutter
Buttes, north of Sutter Buttes and Grass Valley.

Figure 4: Existing air quality monitoring stations and the proposed VOC
measurements. Black starts show the locations of the existing stations.
Green starts show the locations of the PAMS stations. Blue and red
starts show the proposed VOC measurements in the region. An assessment
study is suggested at the stations with red starts to verify whether VOC
levels are above the minimum detection limit.

*PAMS stations:*

Elk Grove-Bruceville, Sacramento-Airport Road, Sacramento-Del Paso,
Folsom-50 Natomas Street, Madera, Clovis Villa, Fresno-1^st^ Street,
Parlier, Bakersfield-Golden State, Arvin, and Shafter.

*Proposed Bay Area VOC measurements:*

Morgan Hill/Gilroy, Labmby Road, Castro Valley, Vallejo, San Jose, Santa
Rosa, Livermore, Bethel Island, Patterson Pass, Creater(?) Peak,

*Proposed San Joaquin Valley VOC measurements:*

Tracy, Modesto, upwind areas of Modesto, downwind areas of Modesto, Kern
Wild Refuge, Early Mart, south east of Elk Hills, east of Stockton, east
of Fresno and east of Bakersfield. The last 3 stations are over
foothills.

*Proposed Sacramento Area VOC measurements:*

Walnut Grove tower, Davis/Dixon, Sloughhouse, north of Woodland, Sutter
Buttes, and north of Sutter Buttes.

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