1. Draft Recommendations for the PAMS Network in the Northeast and Mid-Atlantic States
Hilary Main
Sonoma Technology, Inc.
Petaluma, CA
Presented at NESCAUM- and MARAMA-sponsored Meetings
May 4 and 7, 2001
Putney VT and Baltimore MD

2. Acknowledgements NESCAUM and MARAMA for funding
State and Regional EPA monitoring and analysis staff for comments, suggestions, and discussion
Charlie Blanchard (ENVAIR), Joan Bursey (ERG), Paul Roberts (STI) for technical discussion and research
John Silvasi (EPA) for assistance

3. Objectives of the Project
Identify minimum type and number of observations needed to satisfy PAMS goals
Assist in developing recommendations for potential changes to the network to best balance or redirect resources to meet the PAMS goals

4. Deliverables Literature Review in Support of PAMS Program Assessment
PAMS Data Validation for the Northeast and Mid-Atlantic States,
Statistical Summary of PAMS Data Collected in the Northeast and Mid-Atlantic States
Draft Recommendations for the PAMS Network in the Northeast and Mid-Atlantic States
Recommendations for the PAMS Network in the Northeast and Mid-Atlantic States
Electronic copy of data files (AIRS, VOCDat, AMDAS) and statistical summaries (Excel)

5. Proposed PAMS Data Analysis Objectives and Goals (1 of 2)
Objective: To contribute to tracking and refining emission control strategies.
Goal: To help assess ozone control programs by
identifying key constituents and parameters
tracking trends
characterizing transport
assisting in forecasting episodes
assisting in improving emission inventories
STAPPA/ALAPCO, 2000

6. Proposed PAMS Data Analysis Objectives and Goals (2 of 2)
States and EPA should also consider how PAMS might benefit other programs including how PAMS may:
help characterize ambient air toxics, support modeling, and track key trends
help characterize nitrogen emissions and ambient concentrations
provide data for evaluation of particulate matter and regional haze
enhance special studies
STAPPA/ALAPCO, 2000

7. PAMS Site Types Type 1 Type 2 Type 3 Type 4
Upwind and background characterization
Type 2
Maximum ozone precursor emissions impact
Type 3
Maximum ozone concentration
Type 4
Extreme downwind monitoring
U.S. EPA, 1994

8. Evaluating Site Type Population density Abundant species
# species above DL
Composition changes with time of day

9. Possible Changes in Site Designations
Kittery ME more indicative of a PAMS Type 3 site than a Type 2 site
New Brunswick (Rutgers) NJ more indicative of Type 3 site than a Type 1/4 site
Arendstville PA data and location consistent with a Type 1 or 4 site. Make this an official PAMS site.
Raleigh and Charlotte NC data and locations consistent with Type 2 sites
Enochville NC data and location are consistent with a Type 1/4 site
Garner and Mecklenburg County NC data and locations consistent with Type 3 sites

10. Other Handouts Draft Table 1-1 current site information
Draft Table 1-2 upper-air met site info
Rough draft recommendation summary tables
Table A-1 - stakeholder questions

11. How can PAMS hydrocarbon data quality be improved?
Continue regional quality assurance efforts
Develop a consistent regional approach to validation techniques and data quality standards
Consider a regional approach to data analysis
Work to reduce the unidentified portion of the TNMOC
Work to eliminate the Nafion dryer
Provide coordinated approach to NOy calibration and operations

12. Are there any sites at which VOC measurements can be discontinued?
Primary benefit of dropping a site is a reduction in the monitoring burden
Disbenefits include disuse of equipment already purchased, net loss in spatial coverage
What are primary data uses?
Compare time series, side-by-side box plots, summary statistics, fingerprints, and scatter plots using VOCDat, SYSTAT, and AMDAS

13. Measures of Similarity
Compare median composition (including linear regression)
Overlapping interquartile ranges
Overlapping confidence intervals around means
AMDAS side-by-side box plots and p-value statistics

14. Urban (Type 2 and 2A) Sites
Urban PAMS site
Principal uses of data: assess emission inventories and track trends
Data analyses focus on morning concentrations and ratios
Lynn

15. Drop speciation at Queens or Bronx?

16. Drop speciation at Queens or Bronx?
slope=0.88
int.=0.16

17. Living Classroom?

18. Drop speciation at Clifton Park
slope=0.84
int.=0.0

19. Retain speciation at Hamden
slope=0.53
int.=0.22

20. Lee District School?
r2=0.64
slope=1.1
int.=0.19

21. Retain speciation at Camden

22. Maximum Ozone Sites (Type 3)
Enriched
Aged
Principal uses of data: track trends in ozone and precursors, study photochemistry, assess transport,
Data analyses focus on afternoon concentrations and ratios

23. Drop speciation at Rider College
slope=0.47 (0.81)
int.=0.1 (-0.01)

24. Drop speciation at Kittery or Newbury?
slope=0.65 (0.92)
int.=0.16 (0.12)

25. Drop speciation at Aldino
slope=1.26 (1.1)
int.=0.0 (0.02)

26. Investigate Borderland
slope=0.58 (0.84)
int.=0.05 (0.04)

27. Drop speciation at Agawam
slope=1.28 (0.71)
int.=-0.2 (-0.02)

28. Modify W. Greenwich
This site fills a spatial gap, the composition is aged, shows little change with time of day, isoprene is dominant, and concentrations are low. However, the unidentified is more than 60%:
Retain speciation but expand the species list to reduce the unidentified. Consider reducing sample frequency to every 6th day. Or
Drop speciation and employ continuous NMHC monitor (with sufficient DL).
(High unidentified also at Philadelphia, Fort Meade, Bronx, and Queens)

29. Drop speciation at or modify Truro
Concentrations are low and measurements are infrequent compared to Cape Elizabeth or Acadia:
Drop speciation or
Sample on an episodic basis or
Sample on a reduced schedule

30. Modify Ware
Biogenic-dominated site. The interpretation of chromatograms is difficult.
Change to canister collection
Investigate broader range of species, particularly biogenics
Move auto-GC to Borderland for investigation of possible source(s)?

31. Add CO to selected sites
Add sufficiently resolved CO to type 2 sites

32. Add CO to selected sites
Consider adding high resolution CO to selected non-urban sites

33. NOx and NOy
The current NOx monitors are adequate for the urban sites (Type 2 and 2A)
Use NOy monitors at the non-urban sites, as these monitors more accurately reflect concentrations of the nitrogen species including nitric acid and PAN.
If NOy measurements are added, maintain a conventional NOx measurement at all sites that currently have them during the first year to facilitate comparison between NOy and NOx data.
Consider adding NOx and/or NOy monitors within each of the PAMS metropolitan areas, at three to six downwind suburban or rural compliance monitoring locations where ozone is presently measured to improve the delineation of the transition from urban, VOC-limited to NOx-limited regions.

34. Should some hydrocarbons be added or discontinued?
Reduce peak misidentification of toluene, i-pentane, isoprene, and 1,2,4-trimethylbenzene
Report lump sum of 2,3-dimethylbutane, 2-methylpentane, and 3-methylpentane; m-ethyltoluene and p-ethyltoluene; m-diethylbenzene and p-diethylbenzene
Add 1,3-butadiene and MTBE

35. Should averaging times be changed? (Time series view)

36. Should averaging times be changed? (Average Diurnal View)
Toluene

37. How many samples are required?
Bronx

38. Box Plot Summary
Outliers
Whisker
Notch
around
median
Median
95 % C.I.

39. More than 25 samples needed to:
McMillan
Toluene (ppbC)
Daily, morning
Evaluate day-of-week patterns
Evaluate emission inventories
Evaluate ozone episodes
Perform receptor modeling
Mon.
Fort Meade
Toluene (ppbC)
Every third day,
morning
Mon.

40. Can NMHC be used instead of speciation?
Continuous (1-hr) measure of NMHC issues: costs, comparability, detection limits
Possible sites:
Type 2A Clifton Park, Bronx or Queens
Little diurnal variation - W. Greenwich

41. Carbonyl Measurements
Bronx 1998
Carbonyl data are used for
assessing trends
applying and evaluating models
studying ozone formation
characterizing transport
supporting the toxics program
Chicopee

42. What carbonyl species to measure?
Analyze entire suite of compounds in the cartridges (formaldehyde to tolualdehyde)
Include MVK and methacrolein (isoprene break down products)
At urban sites, focus on formaldehyde
Install continuous formaldehyde at at least one urban and one downwind site for evaluation

43. Carbonyl Measurements
Scenario 1: retain every third day collection for 3-hr samples and 24-hr every 6th day for toxics
Reduce number of samples at Type 2 sites from 8 daily to 2 per day
Do not collect carbonyl samples at Type 2A sites
Add 2 3-hr samples at selected downwind sites (use stepwise process to evaluate data)

44. Carbonyl Measurements
Scenario 2: retain the 24-hr cartridges and switch to continuous formaldehyde
Add systems to selected Type 2 and downwind sites
Augment downwind sites with occasional 3-hr cartridges, at least 2 samples per day, entire suite of species

45. Year-round sampling?
Primary data uses include annual trends, seasonal concentrations, support toxics program
Also - quality assurance, model evaluation, exposure assessment, support PM program
Toxics species in the PAMS target list - benzene, toluene, ethylbenzene, xylenes, styrene, formaldehyde, acetaldehyde, (1,3-butadiene?)

46. PAMS may be a suitable surrogate for annual 24-hr concentrations
slope=1.10
int.=-0.06

47. Recommendations
For year-round 24-hr samples at PAMS sites, work with the toxics community to assess if the morning PAMS data are a reasonable surrogate for the year-round samples. Or consider expanding the canister analysis to include more toxic compounds.
At sites that report only the PAMS target species (on an annual basis), either
Continue to collect the 24-hr samples on a 1-in-6 day schedule but expand the list of species to include carbonyls and toxic compounds, or
Reduce the number of 24-hr samples collected (e.g., to a 1-in-12 schedule to use for quality assurance purposes).
For summer only 24-hr samples, drop 24-hr canisters.

48. Surface Meteorology Collocated data Lums Pond
Met-adjustments for trends
Emission inventory
Source apportionment
Model evaluation
Lums Pond
Propene
Propane
Wind speed, wind direction, temperature
Measure of solar radiation

49. How to optimize PAMS upper-air measurements?
Upper-air data are critical for
Supporting trajectory analyses
Identifying key meteorological phenomena conducive to ozone formation and transport (nocturnal jet, mixing height evolution, recirculation, sea breeze development)
Supporting model evaluation (wind field development)
Supporting forecasting

50. How to optimize PAMS upper-air measurements?
Continue upper-air measurements and strive to increase the utility of the data
Document sites
Take regional approach to validation, data access, and analysis tool development
Ensure archival of both consensus and moments data from LAP/RASS
Get data into AIRS or regional database for easier dissemination among states

51. Additional Recommendations Forthcoming
Which parameters and sites help forecast episodes?
Which parameters and sites best track transport?
Which parameters and sites are best for modeling ozone formation and transport?
What data are relevant to PM/regional haze studies, acid deposition, and the SIP call?
Year-round VOC issues, continuous NMHC information, NOy site recommendations, tenax, aethelometers, etc.