Transcript Framework for US AQ Management and Decision

Framework for U.S. Air Quality
Management and Decision-making
Judith C. Chow ([email protected])
John G. Watson
Desert Research Institute
Nevada System of Higher Education
Reno, NV, USA
Presented at:
The Workshop on Air Quality Management, Measurement,
Modeling, and Health Effects
University of Zagreb, Zagreb, Croatia
24 May, 2007
Objectives
• Review Air Quality Management
Framework
• Introduce NAAQS establishment
process
• Discuss new PM NAAQS
• Specify timeline for
implementation of standards
Framework for Air Quality
Management
Establish
Goals
Air Quality Management Theory
NAAQS
Track and
Evaluate
Results
Attainment date
Monitoring (air and emissions)
Receptor modeling
Determine
Emissions
Reductions
Scientific Research
Implement
and Enforce
Strategies
Sources comply
Permits
Enforcement
Monitoring
Inventories
Analysis & Modeling
Develop
Programs to
achieve
Allocate reductions to source
categories. Develop Implementation
Plans to achieve needed reductions.
(SIPs)
Bachmann, JAWMA, 2007
U.S. Federal Air Pollution
Control Legislation (1963-70)
• The Clean Air Act (CAA) of 1963
– Develop and improve state/local air control
programs (US$65M)
• CAA Amendments of 1967
– Maintain state/local air programs (US$55M)
• CAA Amendments of 1970
– Established structure for air quality
management (U.S. EPA set NAAQS)
– EPA to regulate stationary sources
Technology-based standards for new sources
Risk-based standards for hazardous air pollutants
Percent change
Comparison of U.S. Growth
and Emissions
Year
Basic Facts about U.S. National Ambient
Air Quality Standards (NAAQS)
• The Clean Air Act directs U.S. EPA to
identify and set national standards for
pollutants with adverse public health
and environmental effects.
• The Clean Air Act also requires EPA to
review each standard at least once
every 5 years.
• US EPA established NAAQS for six
criteria pollutants:
– ozone, carbon monoxide, sulfur dioxide, nitrogen
dioxide, lead, and particulate matter (PM)
Setting and Achieving the NAAQS
• Setting the standards
– Health effects
– Environmental effects
• Achieving the standards
– Cost
– Time needed to attain the standards
• Key parts of a standard:
–
–
–
–
Indicator (O3, PM2.5, etc.)
Level (e.g., 0.12 ppm, 150 µg/m3)
Averaging time (e.g., 1 hour, 24 hours, annual)
Form (e.g., one exceedance per year, never to be
exceeded)
NAAQS Review/Revision Process
Research on:
Atmospheric Processes,
Air Quality, Exposure,
Health and Welfare
Effects
Research
Planning &
Coordination
Peer-Reviewed
Published Studies
Research Needs
Identification
& Prioritization
Final
Decisions on
Standards
CASAC: Clean Air Scientific Advisory Committee
EPA Air
Quality
Criteria
Document
(AQCD)
Reviews by
CASAC and
the public
Public
Hearings and
Comment on
Proposals
EPA Staff
Paper (SP)
and Risk
Assessment
(RA)
Reviews by
CASAC and
the public
Proposed
Decisions on
Standards
Chronology of Photochemical
Oxidant (as Ozone) NAAQS
Year of
Promulgation
Level
Averaging
Time
Form
1971
0.08 ppm
(primary =
secondary)
Hourly
Not to be exceeded
more than once per
year
1979
0.12 ppm
(primary =
secondary)
Hourly
Not to be exceeded
more than once per
year
1997
0.08 ppm
(primary =
secondary)
8-hr average
Three-year average
of the annual fourth
highest daily
maximum 8-hr
average
2007 (proposed)
0.06 ppm
(primary)
8-hr average
Proposed secondary
to be below 0.8 ppm
in the range of 0.060.07 ppm
Ozone NAAQS Attainment
Timeline
Date
July 18, 1997
Process
US EPA promulgates ozone NAAQS
2000
US EPA designates non-attainment
areas
States submit Implementation Plans for
meeting the eight-hour standard. For
areas which haven’t met the current
one-hour standard, ongoing efforts are
sufficient through the current
attainment dates
2003
2012
States have up to 10 years to meet
NAAQS plus two one-year extensions
Ozone NAAQS timeline for areas
classified as “transitional”
Date
Process
July 18, 1997
2000
US EPA promulgates ozone NAAQS
States submit Implementation Plans to
address transported air pollution. US
EPA classifies areas as “transitional.” All
new non-attainment areas are eligible
to be “transitional.”
States achieve reductions from regional
sources
2004
2007
2012
States assess effectiveness of regional
reductions
States have up to 10 years to meet
NAAQS plus two one-year extensions
Chronology of PM NAAQS
Year of
Promulgation
Indicator
1971
TSP
(Total
suspended particulate
matter)
Level
Annual
24-hr
75 µg/m3
260 µg/m3
(geometric mean)
(primary; not
to exceed >1/yr)
150 µg/m3
(secondary; not to exceed
>1/yr)
1987
PM10
50 µg/m3
150 µg/m3
1997
PM10
50 µg/m3
150 µg/m3
PM2.5
15 µg/m3
65 µg/m3
(arithmetic mean)
(98th percentile
averaged over 3 years)
PM2.5
15 µg/m3
35 µg/m3
(arithmetic mean)
(98th percentile
averaged over 3 years)
2006
PM10
None
150 µg/m3
2006 (proposed but
rejected)
PM10-2.5
None
70 µg/m3
2006
(arithmetic mean)
(arithmetic mean)
(PMcoarse)
(not to exceed
>1/yr, 3 years)
(99th percentile
averaged over 3 years)
(not to exceed
>1/yr, 3 years)
(99th percentile
averaged over 3 years)
PM2.5 NAAQS Attainment
Timeline
Date
Process
July 18, 1997
US EPA Promulgates PM2.5 NAAQS
September 16, 1997
NAAQS become effective
July 1, 1998
States submit Monitoring Plans
1998 – 2000
Monitors put in place nationwide
1998 – 2003
Monitoring data collected
1999
US EPA designates areas as “unclassifiable”
2000
US EPA completes five-year scientific review of NAAQS
2002
US EPA reviews PM2.5 NAAQS
2002 – 2005
US EPA designates non-attainment areas
2005 – 2008
States submit Implementation Plans for meeting the NAAQS
2012 – 2017
States have up to 10 years to meet NAAQS plus two oneyear extensions
Limitations of the U.S. PM2.5
Standards
• Causal relationships of PM2.5 to health not established;
only epidemiological relationships
• 24-hour average masks peak exposures of shorter
duration
• Highest concentrations neglected or attenuated by
statistical form
• Already regulated as a subset of existing PM10 standard
• Is not accurately measured by practical Federal
Reference Methods (FRMs) under all circumstances
• Other indicators are more specific to respiratory and
cardiovascular effects
(several of these are due to available measurement
technology)
Why use 98th Percentile for
24-hr NAAQS?
• Statistical robustness
• Statistically significant associations
with health effects:
PM2.5 FRM Mass versus Frequency (%)
Site 117 - El Paso Tillman (ELPATI, 481410002)
2000 - 2002
99.99
100
– Hospital Admissions
– Respiratory symptoms
95
90
80 70 60 50 40 30 20
10
5
1
0.1
0.5 1
5
10
20 30 40 50 60 70 80
90
95
99
99.9
70
50
3
PM 2 .5 FRM Mass ( g/m )
– Mortality
99.599
30
20
10
7
5
3
2
1
0.01 0.05
Frequency (%)
2006 versus 1997 PM2.5
NAAQS
• Same levels for primary (health) and
secondary (welfare) standards
• Minor changes in ambient monitoring
• More stringent spatial averaging
requirements
• More relaxed data completeness
requirements
• Simplification of reporting requirements
PM2.5 Federal Reference
Methods (FRMs)
Andersen RAAS BGI PQ-200
Thermo Fisher
Scientific, formerly
Andersen Instruments,
Smyrna, GA
BGI, Inc., Waltham, MA
Partisol Sampler
Thermo Fisher Scientific,
formerly Rupprecht &
Patashnick, Albany, NY
URG MASS
URG Corp.,
Raleigh, NC
PM2.5 Monitoring Changes
• Samplers with very sharp cut cyclones
(VSCC) would be FRM (had been FEM)
• Requires improved impactor oil for WINS
• Time limit to recover samples increased
from 96 to 177 hours
• Allows up to 30 days* to condition and
weigh retrieved filters when transit
temperature is less than average ambient
temperature during sampling
*In the past, the number of days was determined by: days=34-T[°C]; T=storage temperature <25 °C
Size-selective Inlets
WINS Impactor
Very sharp cut
cyclone (VSSC)
PM2.5 Spatial Averaging
Changes*
• Current
– Correlation (r) ≥0.6 between monitor
pairs
– Difference ≤20% between monitor values
• Proposed
– Correlation (r) ≥0.9 between monitor
pairs
– Difference ≤10% between monitors
*
Determined on a seasonal basis
PM2.5 Data Completeness Changes
• Required ≥75% data completeness per quarter
• Collocated sampler data can substitute for missing
primary sampler data
• Allow 11 or more samples per quarter if calculated
annual standard design value exceeds the NAAQS
• For a quarter with < 11 samples, allow data
substitution of an historically low 24-hr value (to
reach 11 samples) if the results yield an annual
mean, spatially averaged annual mean, and/or
annual standard design value exceeding the NAAQS
PM2.5 Data Reporting Changes
• No longer need to report the following parameters
to EPA’s Air Quality System (AQS;
http://www.epa.gov/ttn/airs/airsaqs/)
–
–
–
–
–
Flow rate
Coefficient of Variance
Sample volume
Minimum & maximum temperature
Minimum & maximum pressure
• Continue to report:
– PM2.5 concentration
– Average temperature
– Average pressure
• State and local agencies need to retain information
on parameters no longer reported to AQS
Why a Proposed PM10-2.5
Standard?
• Court decision
(D.C. Circuit in 1999 and 2001)
– PM10 composed of PM2.5
– Need to regulate coarse PM independent of
PM2.5
• Recent studies showing PM10-2.5 effects*
– Inflammation and aggravation of allergic
effects
– Coughs in children
– Increased hospital admissions
*Generally stronger for short-term rather than long term effects
Limitations to the PM10-2.5
Standard
• Includes any ambient mix of PM10-2.5
dominated by resuspended dust from high
density traffic on paved roads and PM
generated by industrial sources
• Excludes any ambient mix of PM10-2.5
dominated by rural dust and soils and PM
generated by agricultural and mining sources
– Agricultural sources, mining sources and other
similar crustal PM10-2.5-dominated sources shall not
be subject to control in meeting this standard
Concerns about Proposed
Revisions to PM Standards
• Are levels set to provide an adequate
margin of safety to protect sensitive
populations, given the quality of the
measurement and health effects data?
• Should a separate short-term standard for
PM2.5 be established based on visibility
concerns?
• Do measurement, characterization, and
health-effects studies adequately support
the cited differences in toxicity between
rural and urban dust?
• Why not control agricultural, mining and
other non-urban dust sources?
For More Information:
See the June issue of the
Journal of the Air & Waste Management Association
for the “Critical Review” by
John Bachmann
“Will the Circle be Unbroken: A History
of the U.S. National Ambient Air
Quality Standards.”