1. Current Capabilities and Future Directions of CASTNET
RPO National Technical Meeting
June 8, 2005
Gary Lear
Office of Atmospheric Programs (OAP)

2. PAR107 CASTNet Site Parsons, WV
CASTNET Objectives
Monitor the status and trends in regional air quality and atmospheric deposition
Provide information on the contribution of atmospheric pollution to ecosystem conditions
Provide measurements for validating and improving atmospheric models
PAR107 CASTNet Site Parsons, WV

3. CASTNET Today Sites 87 (+ 2 collocated) Sampler
Filter pack - Teflon®, Nylon®, and Whatman®
Chemical analysis
Laboratory extraction and ion chromatography
Gaseous species
HNO3, O3, SO2
Particle species
NO3, NH4, SO4, Base cations
Meteorology
Temperature, precipitation, relative humidity, solar radiation, wind speed, wind direction
Sampling height
10 m
Sampling frequency
168 hours (1 week)
Sampling schedule
Tuesday to Tuesday
Data availability
4-7 months
CASTNET filter pack assembly
(2 Alaska sites not shown)

4. CASTNET Has Provided Accountability for Many OAR Programs
Trends in SO2 Concentrations
Reporting requirements due to statute and international agreements
CAAA effectiveness in reducing acid deposition
NAPAP Report to Congress
US-Canada Air Quality Agreement Progress Report, etc.
Annual reporting requirements
Acid Rain Program Progress Report,
NOx Budget Program Progress Reports, etc.
PART (Program Assessment Rating Tool)
Establish baselines for our programs
Set annual, progressive environmental goals
Results are tied to budgets
Trends in Total Deposition

5. EPA Must Continue to Provide Accountability for Emerging Issues
Areas Designated Nonattainment for Ozone and PM2.5 NAAQS in 2004
Clean Air Interstate Rule (CAIR)
A regional control program requires regional accountability measures
Source attribution
Ecosystem conditions
Eutrophication
Critical Loads
Model development and validation
EPA makes decisions worth $10 Billion based on these model output
Air Quality Forecasting
Convergence of measured and modeled results
NO3+HNO3 Bias (CMAQ – CASTNET)

6. National Academy of Sciences Air Quality Management in the United States (2004)
Key Findings
“The current lack of rural monitoring sites severely hampers the AQM system’s ability to address multi-state airshed pollution problems or to assess and mitigate pollutant impacts on natural and managed ecosystems.
“The nation’s air quality monitoring network is dominated by urban sites, limiting its ability to address a number of important issues, such as documenting national air quality trends and assessing the exposure of ecosystems to air pollution.”
Recommendations
“New monitoring methods to respond to the changes in air quality and monitoring data needs that have occurred over the past 30 years.
“Increased number and distribution of air quality monitoring stations in rural, agricultural, and remote forest areas, aided by a statistical design that will improve spatial and temporal estimates of exposure.
“Enhanced accessibility of ambient air quality measurement data to the scientific community and the public.”

7. Regionally Representative
Gothic, CO
Rural is important because it gives representative data:
Unaffected by local sources
Minimized variability
Specific siting criteria
Variability of local sources can obscure regional signals and long-term trends

8. This is the Challenge! Respond to our unmet national monitoring needs:
Characterize regional air quality
Characterize secondary fine particulates and their precursors
Reduce uncertainty in air quality modeling applications
Get data to our scientists and the public
… and still maintain:
Stable operating costs for our monitoring networks
Robust, reliable equipment that will provide quality high-resolution measurements
The ability to provide traditional accountability indicators

9. Expanding the capabilities of CASTNET
Add advanced instrumentation to sites
Use multi-pollutant monitors to save on cost
SO2, HNO3, HNO2, O3, NH3,
SO4, NO3, NH4, Base cations
NOy
Seek local partners to complete NCORE Level 2
Hourly resolution
Real-time availability of data
Implement in 3-Phase approach
Prototype
Pilot
Full deployment

10. NCORE and CASTNET Measurements
IMPROVE/
STN
Expanded CASTNET
NCORE Level 2
Gases O3
1-hr
SO2
1-wk
NOy NO
NH3
TBD
HNO3
HNO2 CO
PM2.5
Crustal
24-hr/3-day
FRM Mass
Continuous Mass
OC/EC
Particle
SO4
24-hr/3-day*
NO3
NH4
Base Cations
Meteorology
* PM 2.5 fraction

11. Criteria for Multi-Pollutant Instruments
7 day unattended operation
1 hour measurements of major nitrogen and sulfur species
Detection Limit < 0.1 ug/m3 for all species
Relative percent difference from standard methods < 20%
Consumable liquids < 10 gallons/week
Non-hazardous waste liquids or by-products
Data available within 24 hours of sampling
Reasonably sized (fit within existing CASTNET shelter)
Internal, automated quality assurance checks
Does not require specialized instrument training of field technician
Remote data availability
Sampling height between 4 and 10 m
Evaluation committee from OAP, OAQPS, ORD, NPS, USFS, Cherokee Nation Tribe, Midwest RPO, and NOAA

12. Multi-Pollutant Instrument Selected for Additional Testing
Sampler
MARGA
Chemical analysis
Ion Chromatography
Gaseous species
HNO3, HNO2, SO2, NH3
Particle species
NO3, NH4, SO4, Base cations
Sampling height
4 m
Sampling frequency
1 hour (minimum is 20 min)
Sampling schedule
Continuous
Quality Assurance
Continuous internal standards
Data availability
1 hour (24 hours to Web)
MARGA (Monitoring Instrument for Aerosols and Gases)
-- Developed by ECN (Energy Research Center for the Netherlands) and APPLIKON, INC

13. Principles of MARGA sampling
1. Ambient air composed of gases and particles
3. Particles pass through the denuder into the steam chamber
Rotating denuder
4. Particles “grow” as steam condenses
2. Gases are removed from air into the rotating denuder liquid
5. “Grown” particles condense on sides of condenser and collect at bottom of chamber
6. Liquids containing gases and particles are analyzed separately by liquid chromotography

14. Comparison of MARGA and Denuder/Filterpacks
Average Conc.
Slope vs Median
R^2
ug/m3
Marga 1
Marga 2
Marga 3
Marga 4
HNO2
1.5
1.07
1.13
0.94
0.93
0.99
0.96
0.98
SO2
5.2
1.03
1.04
0.88
0.91
NH3 3 1
1.1
0.9 Cl
1.02
0.71
0.8
NO3
4.7
0.97
0.87
SO4
3.5
1.05
0.82 Na
1.01
1.17
0.76
NH4
1.9
0.81
0.83
N=12

15. Phase I (2004-2006) Funded: $1.2 M OAP, OAQPS and CASTNET
Evaluate and select prototype instruments for testing
Short-term high-intensity testing of selected instruments
August 2005 (4 weeks)
NOAA, EPA team using standard methods
Two sets of instruments collocated for precision determination
Gas/Particle Analyzer
Gases: HNO3, SO2, HONO, NH3
Particles: SO4, NO3, NH4, Cl, Ca, K, Mg, Na
Trace-gas analyzers (on-going)
NOy (NO + NO2 + NOz )
SO2 CO
Sandy Dasgupta’s GPIC (?), Others?
Beltsville participants include scientists from NOAA, OAP, OAQPS, ORD, University MD, Howard University
Four MARGAs operating simultaneously with denuder/filter packs at Aplikon headquarters for preliminary precision and accuracy determinations in April 2005

16. Phase I (2004-2006) Funded: $1.2 M OAP, OAQPS and CASTNET
Evaluate and select prototype instruments for testing
Short-term high-intensity testing of selected instruments
Long-term testing of selected instruments
July July 2006 (1 year)
Three CASTNET sites
Gas/Particle Analyzer
Trace-gas analyzers (on-going)
Dasgupta’s GPIC (Bondville)
Passive Devices
Low-flow denuder/filter pack for NH3 and NH4
Ogawa devices for NH3
Continuous data available to public within 24 hours

17. Phase I (2004-2006) Funded: $1.2 M OAP, OAQPS and CASTNET
Evaluate and select prototype instruments for testing
Short-term high-intensity testing of selected instruments
Long-term testing of selected instruments
Evaluation (January – September 2006)
Determine data quality objectives for all instrumentation
NCORE
Ecosystem and deposition monitoring
Trend determination
Modeling needs
State and local needs
Evaluate results against DQOs
Make recommendations

18. Phase II (2006-2007) Funded: $1.0 M OAR and CASTNET
Contingent on successful Phase I
Pilot program of up to 10 sites
Install 5-7 additional sites for routine monitoring and operation
Instrumentation
CASTNET Filter packs
Gas/Particle Analyzers and NOy Analyzers
Seeking partners for PM2.5 and CO measurements
Actual site locations based on:
Providing regional-scale coverage
Collocation with IMPROVE
Consultation with National Park Service, RPOs, states and tribes
Filter pack measurements will continue for establishing instrument baselines and bias
Continuous data available to public within 24 hours
(Actual locations to be determined)

19. Phase III (2006-2008) Contingent on successful Phase II Funding
$3.5 Million
Budget cycle requires proactive request
Funding returned if instruments not recommended
Full implementation at enhanced sites
Actual site locations based on:
Providing national coverage
Collocation with IMPROVE
Consultation with National Park Service, RPOs, states and tribes
Data available through AQS and CASTNET web site
Decommissioning of old technology is contingent on alternative modeling techniques
Encourage partners to join the network
(Actual locations to be determined)