1. Ambient Measurement Programs in the United States
Rich Scheffe, United States
Environmental Protection Agency
Good Day….
The purpose of this presentation is to provide you with an overview of some exciting work being done by EPA and representatives from various State, Local and Tribal organizations.
The reengineering of air monitoring is going forward in no small measure in response to many of our mutual concerns, voiced during the PM 2.5 implementation.
The future is upon us and we want to begin the process of getting you engaged in the effort, so that you may focus your staffs on the important work ahead.
This strategy will impact your:
Program’s policies and focus (New Data will give context to issues now being raised-toxics, diesel PM)
Budgets (this work is expensive)
Ability to provide air quality products to our interested and informed public. (Using AIRNOW and AQI and local websites)
We are limited in time and want questions at the end. We will be posting more detailed information on the AIRWEB site and hope you will read find it helpful.
EMEP Workshop
New Orleans, Louisiana
April 20, 2004

2. Topics
Current networks…routine
Anticipated changes
Overview of incommensurability and artifact issues

3. National Level Routine Networks…S/L/T’s, EPA
PM2.5: FRM, cont., spec (trends (daily), SIP, IMPROVE, SS); >1000 sites
PM10 >1000 sites
O3 > 1000 sites
NOx/NO (NO2) > 400
SO2 > 400
CO > 400
Pb > 400
O3 precursors, PAMS >70 sites
S, N deposition, CASTNET, > 50 sites

4. Current Network > 3,000 “sites” Many are single pollutant sites
Different purposes and scales
Expensive
Fixed
Redundant
Outdated
PM/SO2
VOC’s PM O3 CO
SO2
Toxics
50 mi
15mi
25 mi
35 mi
Real-time
PAMS
IMPROVE
CASTNET

5. PM2.5 Networks SS Mass Sampling Routine Speciation 8 ~175 SIPs
~ 1050 FRMs
~ 200 cont.
~ 54 Trends
~175 SIPs
~150 IMPROVE 8

6. 2000-2002 3-Year Average Annual Mean PM2.5
Data from AQS 7/9/03. Sites that operated anytime (n=1239)

7. Urban and Rural PM2.5 Speciation Networks
Active Sites as of 1/20/04: EPA data from AQS, IMPROVE data from VIEWS

8. Annual Urban PM2.5 Speciation Patterns

9. Annual Rural PM2.5 Speciation Patterns

10. Annual Rural PM2.5 Speciation Patterns
Annual Urban PM2.5
Speciation Patterns
Annual Rural PM2.5 Speciation Patterns

11. Annual Average Urban Excess

12. Supersites IRD Study Domain
Southeastern Canada
New York
Pittsburgh
Baltimore
Fresno
St. Louis
Los Angeles
Atlanta
Houston
Phase I
Phase II
Both Phases

13. Pittsburgh: Avg. Size Distribution
Courtesy: Prof. Jose-Luis Jimenez et al. Dept. Chemistry & CIRES University of Colorado at Boulder

14. Strong Nucleation Pittsburgh, August 11, 2001 August 11, 2002
12x104
Number (#/cm3)
6x104
105
500
104
100
dN/dlogDp (cm-3)
Response
Particle Size (nm)
103 10
102
00:00
06:00
12:00
18:00
24:00
Time of Day

15. Chemistry of Growth: Particle Mass Spectra at 20-33 nm
Detection of Nucleation
by Particle Sizer
Remember to talk about all points on the graph
Zhang, Stanier, Caragaratna, et. al. Insights into the Chemistry of Nucleation Bursts and New Particle Growth Events in Pittsburgh based on Aerosol Mass Spectrometry. Environ. Sci. Technol., submitted.

19. Don’t believe it

21. Areas with PAMS Networks
PAMS areas
Type #2 site
Type #1, #3, #4 site

23. Air Toxics Monitoring Network: Pilot sites and proposed trend sites

24. Comments on Historical Routine Networks
Adequate ground level spatial coverage
PM2.5 mass, ozone
But,
Very limited multiple pollutant sites
Act of convenience rather than design
Aerosols (mass and species)
too much reliance on integrated techniques providing no diurnal characterization
Criteria gases
Except for ozone and NO, many meaningless measurements
Trace levels, source oriented/microscale siting (CO, SO2)
Other gases
NOy….very limited
True NO2..?
VOCs…mostly ozone season through PAMS
Other precursors and indicators
Nitric acid and ammonia….episodic/intensive programs only
Peroxides, hydroxyl radical….intensive programs only
Artifacts/problems….later

25. Changes expected from Implementing National Monitoring Strategy
Based on these concerns…..
The United States EPA is undertaking a major modification of the national ambient air monitoring networks

26. National Core Network: NCORE
Goal: Move from loosely tied single-pollutant networks to coordinated, highly leveraged multi-pollutant networks with real time reporting capability
PAMS
SO2 O3 PM PM CO PM
IMPROVE
CASTNET PM O3
Toxics

27. Principal Data Objectives of NCore
Public Information
Real-time Input of Data From Across the Country Using Continuous Technologies
Spatial Mapping (E.G., AIRNOW), Health Advisories
Health/Exposure Assessment Support
Input for Periodic NAAQS Reviews
Emissions Strategy Planning (Emphasis on Initial Timeframe)
What are the best emission reduction approaches?
E.g., Provide for Routine Model Evaluation and Source Attribution
Air Quality Trends and Program Accountability
Does the monitoring confirm strategies are working?
Major National Initiatives (Acid Rain, Clear Skies, NOx SIPS, FMVCP)
Including HAPS (National) and Visibility Assessments
Science Support
Backbone for More Diagnostic Level Work (Same for Local Sips), Health Studies
NAAQS Determinations and Related Regulatory Rqmts.
Emphasis on More Pervasive Ozone and PM2.5
Ecosystem assessment support

28. Speciation Program, Air Toxics
NCore Measurements
Level Master Sites Comprehensive Measurements, Advance Methods Serving Science and Technology Transfer Needs
Level 2: ~ 75 Multi-pollutant (MP) Sites,“Core Species” Plus Leveraging From PAMS,
Speciation Program, Air Toxics L2
Level 3 L1
Level 3: Minimum Single Pollutant Sites (e.g.> 500 sites each for O3 and PM2.5 and related spatial
Mapping Support
Minimum “Core” Level 2 Measurements
Continuous NO,NOy,SO2,CO, PM2.5, PM10/PMc,O3,Meteorology (T,RH,WS,WD); Integrated PM2.5 FRM, HNO3, NH3,

29. Proposed Siting Approach – Level 2
“Representative locations”
5-15 km urban scale
50 km or more…regional scale
“contrast with historical search for highest concentrations…at odds with collocation”
Start With “Reasonable” Coverage From Health/ Exposure Perspective
Population Based (Range of Sizes) With Varying Chemical Composition.
Assumes Need for Multiple Pollutants to Tease Out Confounding Factors
Add in Desired Rural Coverage
Accountability of Major National Programs Such As 3P, NOx SIP)
“Operational” Model Evaluation
Equitable Resource (and Constrained) Considerations
Determine Ability of Existing Networks to Address, Modify

30. Proposed Siting Approach – Level 2…
Health meets atmospheric sciences
Suggested Rural Locations for Level 2 Sites 3 2 1 4 10 24 9 12 11 20 7 6 18 19 21 8 5 13 17 16 15 14 23
Transport, Corridor, Background and Inflow Locations

31. Urban & Rural PM2.5 Speciation Networks
Current/Planned
Supplemental Information

32. Overview of Measurement…Modeling incommensurabilities and other issues
Spatial representation
Volumetric (model) versus point representation (measurement)
Breathing level measurements….most of mass often elevated
Measurement Artifacts
Model attempts to characterize reality relative to true ambient properties, and natural removal processes (e.g., deposition to land/water/foliage)
Measurements techniques alter ambient properties (heating, dehumidification), and removal processes (changing concentration gradients) within sampler universe

33. Also troubling is the delineated use of measurements and modeled predictions.
…..Measurements are the current tool for strict regulatory applications, and models are used as a planning tool.
………The reality is that measurements really are just estimates of surrounding reality, and in one sense no different from a predictive output from a model.
……. Both these tools need to be more effectively merged to support in unity a host of regulatory and planning applications.