The Southeast Michigan Air Quality Study Group (SEMAQS)

George Wolff - AIR, Inc.Joan Weidner - SEMCOGChuck Hersey - SEMCOG

SEMAQS History

• Early days (pre 1990s): Command and Control• Communications began after decisions were

made• A model ripe for confrontation

History: Lessons Learned

• Confrontation wastes:– Time– Relationship building opportunities – Opportunity to leverage human knowledge and

resources

History: The New Age

• Tap human knowledge and resources in public and private sector

• Work from ground up instead of top down• Create welcoming atmosphere for exchange of

information and interpretations of data• SEMOS, now SEMAQS, was formed and working for

over 20 years• Resulted in:– Human infrastructure network on regional air quality– Track record of timely NAAQS compliance

Membership

• Government– SEMCOG: Local government representative and group facilitator– Michigan Department of Environmental Quality– U.S. EPA

• Industry– Autos– Utilities– Other stakeholders (e.g., steel mills)

• Other Resources– LADCO– Universities – Canadian national & provincial government– Consultants

Mission

• Achieve air quality standards as efficiently, effectively, and swiftly as possible

• Develop specific strategies that pass 2 tests: – good science – good policy

• Recognize science is rarely deterministic: Focus on weight of evidence

• Enjoy and learn from what we do

SEMCOG7-County Planning Area

Population: 4,705,000

DetroitAnn Arbor

Pollutants of Concern for SEMAQS

• Ozone – Attainment area but 2011 and 2012 violations and lower NAAQS in 2014 possible

• Sulfur dioxide – violation at a Detroit site, sparse monitoring in SE MI and modeled violations possible; size of nonattainment area in question

• PM2.5 – Awaiting redesignation to attainment, but a probable new NAAQS in 2013 could throw us back into nonattainment

• Nitrogen dioxide – Unclassifiable/attainment status– No measured violations but data are sparse– Near roadway monitoring underway– Need more data

Overarching Areas of Interest

• Spatial distribution of pollutions– What can be measured from space?– What is the spatial resolution?– What is the correlation between the vertical slices and

surface measurements?– What is the temporal resolution?– What is the analytical resolution?

• Effectiveness of emission controls– Are there historical satellite data that can be used to

construct pollution trends?

PM2.5

• Trend is down and we expect to meet possible new annual NAAQS in near future with no additional control measures

• 24-hour NAAQS is more problematic– Winter episodes poorly understood– High OC and NO3– Fog appears to contribute to high NO3– Emission inventories for condensable is woeful

• My understanding is that satellite based column profiles correlate poorly with surface measurements (Paciorek & Liu, 2012)

SO2

• SE MI will be declared nonattainment for the new 1-hour NAAQS based on 1 monitor in Detroit

• Unlike any other pollutant, an SO2 violation can be based solely on modeling

• Therefore spatially resolved data is a high priority

O3

• SE MI barely in attainment with 75 ppb NAAQS in 2008-10

• Violation at 1 site occurred in 2011 and in 2012

• Will be in serious difficulty if NAAQS is lowered

Ingredients for High O3 in SE MI

All These Conditions Are Necessary

• Persistent S to SW synoptic air flow• Sunny hot days• LAKE BREEZE

LAKE BREEZES are inadequately resolved in current Photochemical Grid Models

Other Key Issues -Background O3

• North American Background (NAB) – US concentrations in the absence of NA anthropogenic emissions

• NAB sets a limit on the amount of risk that can be reduced.– The lower the NAB, the more risk reduction EPA can claim by

lowering the NAAQS– i.e. - If EPA used NAB of 40 ppb instead of 15-35, 92-100% of

risk would have disappeared.

• NAB establishes the O3 level that can be achieved from State and Federal control Programs– An underestimation of actual NAB will result in failed control

strategies.

EPA’s Definition of Background Inappropriate

• NAB should not be used• USB should be used because US has no control

over Canadian and Mexican emissions• In 1997 O3 review, EPA used modeled mean

monthly diurnal NAB profiles (MI ~ 22 ppb)• This grossly underestimates USB daily

variability and

MeasurementModelNABUSBCanadian/Mexican enhancement

• Max USB = 44 ppb (CME = 30; total O3 = 75 ppb)• 5 x’s total O3 ≥ 75 ppb and Canadian enhancement ≥ 10 ppb.• 2x’s Canadian enhancement ≥ 30 ppb.

(from Wang et al., 2009)

Background O3

• Need help getting USB with latest models• Need help convincing EPA that USB not NAB

should be used

Are We Calculating USB Correctly?

• EPA Zeroing out US anthropogenic emissions creates unrealistic conditions

• A more realistic way to determine the impact of upwind emissions on US O3 concentrations would be to zero out upwind emissions and determine the impact by difference

Summary

• O3

– Background– Lake breeze

• SO2

– Spatial distribution

• PM2.5

– Winter episodes

• NO2

– Spatial distribution