Title: Ozone in Winter in the Upper Green River Basin
1Ozone in Winter in the Upper Green River Basin
- Greater Yellowstone Area Clean Air Partnership
Meeting - October 15, 2008
2Jonah/Pinedale 2005
3Sublette County Wells
4Sublette Co. Gas Production 1980-2007
5How Ozone is Formed
- Formed through a complex series of reactions
between nitrogen oxides and volatile organic
compounds driven by sunlight. -
- Generally thought to occur under sunny, high
temperature situations (i.e., summer months in
urban areas)
6Changes to 8-hr Ozone National Ambient Air
Quality Standard
- Previous Standard 3-year average of the 4th
highest daily 8-hour averaged ozone concentration
0.08 ppm - Standard Revised in May 2008 3-year average of
the 4th highest daily 8-hour averaged ozone
concentration 0.075 ppm - The primary (health-based) and secondary
(welfare-based) standard were set at the same
value
7History of Air Monitoring in the Upper Green
River Basin
- Began ozone monitoring in 2005
- Standard was 0.08 (0.084)
- Found elevated levels
- 4th high 8-hour 0.080 on February 24th
- (Yellowstone monitor that day was 0.049)
- Confirmed that monitor was functioning properly
-
- Recurred in 2006
- 4th high 8-hour 0.075 on February 27th
- (Yellowstone monitor that day was 0.056)
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92005 2006 Top 5 8-hour ozone concentrations
Less than 75 data completeness Began
operation in July 2005
10Theories on Causes
- Monitoring error
- Stratospheric Intrusion
- Transport
- Locally Formed
Jonah 1200 2/27/06
11Theories on Causes - conclusions
- Monitoring error Not Likely
- Checked certifications
- Additional 3rd party audits
- Elevated concentrations at multiple monitors
- Winter 2006 put Chemiluminescent ozone monitor at
Jonah to check for interference and found none - Stratospheric Intrusion Not Likely
- Tight inversion and stagnant conditions for
several days - Transport Slight Possibility
- Other areas had not reported high wintertime
conditions
12Theories on Causes (cont.)
2005
- Locally Formed Most Likely
- Precursors emitted in area
- Suspected tight inversion
- Stagnant conditions
- Sunny, snow cover
13Ozone and Wind Speeds, Jonah, WY, Feb 1-4, 2005
Slide compliments of NOAA
14AQD Response to Ozone Events
- Concerns about elevated concentrations
- Potential for NAAQS violation
- Health effects on local public
- More development planned in SW Wyoming
- Requested proposals for an Ambient and
Meteorological Field Study
15AQD Initiated an Intensive Field Study in Jan.
2007
- Study Objectives
- Determine meteorological conditions
- Identify causes of high ozone
- Identify ozone distribution
- Identify role of ozone precursors
- Develop tools to model ozone formation
162007 Ozone Monitoring Field Study
172007 Continuous Measurements
- Continued monitoring at Boulder, Jonah, and
Daniel South - CastNet continued collecting ozone data
- Wind speed with height at airport
- Seven temporary stations to measure wind speed,
wind direction and ozone
182007 Intensive Operating Periods (IOPs)
- Operational forecasts
- Elevated ozone events likely
- Trigger Intensive Operating Periods (IOPs)
- IOP Measurement Objectives
- Determine structure of atmosphere during high
ozone events - How shallow is the inversion?
- What does the vertical ozone profile look like?
- What differences exist between Jonah, Boulder,
Daniel? - Determine spatial variability of ozone
concentrations around Upper Green River Basin - Determine VOC concentrations
192007 IOP Measurements
- Temporary equipment to measure upper level winds,
temp., relative humidity and ozone at Airport - Aircraft measurements of ozone, temp., VOCs
20Summary 2007 vs. 2005-2006 Weather Patterns
- Weather conditions associated with high ozone
events in 2005-2006 did not occur during 2007 - Lack of snow cover in 2007
- Stronger upper level winds in study area in 2007
- Stronger surface winds in 2007
- Morning surface inversions did not persist
21Meteorology
- Why important?
- Ozone a secondary pollutant
- Ultraviolet light (sunshine)
- Temperature inversion
22Ozone Sunlight
- UV energy from the sun is required to produce
ozone - Historically, scientists believed ozone cant be
formed in low temperatures or areas with low sun
angles (i.e., winter) - Study measured UV energy
- Result when ground is highly reflective, UV
energy is doubled
23Ozone Sunlight
Albedo 0.81 (snow)
Albedo 0.04 (bare ground)
24Preliminary conclusions
- In the winter
- Temperature inversion
- Still air
- Snow cover
- Sunshine
- Ozone precursors present in UGRB
- Produce elevated ozone
252008 Field Study Objectives
- Develop a more complete characterization of
winter ozone events in the Upper Green River
Basin - Provide data for
- Development of a conceptual model of ozone
formation - More accurate numerical simulations of high ozone
events
262008 Study Approach
- Study design based on 2005 2006 high ozone
event data - Identify meteorological and air quality modeling
data requirements - Identify data needed to evaluate initial theories
- Develop episode forecasting protocol
- Use field study website to post daily forecasts
and raw data - Conduct measurements mid-January March 2008
- Continuous Measurements to supplement existing
network - Intensive Operating Periods (IOPs)
272008 UGWOS Continuous Sampling
- Routine data collection at existing sites
(Boulder, Jonah, Daniel South, Pinedale-CASTNET) - Airport operations
- Surface ozone
- Surface winds
- Sodar Site
- Upper level winds, temp
- Detected inversions
- Five temporary surface sites
- Wind speed, wind direction and ozone
282008 UGWOS IOP Measurements
- Inversion layer measurement and columnar ozone
measurement at airport - 800, 1100, 1300, 1700
- VOC/Carbon compounds sampling
- Three hour integrated samples at Jonah, Boulder,
Daniel 400 700, 900 1200, 1400 1700
MST - Aircraft grab samples
- Aircraft
- Morning and afternoon flights
- Ozone, PM2.5, Temperature, Pressure
29Wyoming Daily Max 8-Hr O3 2008 UGWOS Study
Period
3085
75
Compliments of Shell 2008
3175
85
Compliments of Shell 2008
322008 Pinedale Airport Vertical Profiles
11 March _at_ 600 pm
12 March _at_ 400 pm
Temp
O3
No Inversion, no elevated O3
Different wind directions above and below
inversion
Inversion at 100 m
Elevated O3 below inversion
Raw data subject to change
33Role of Mixing Heights
SODAR Mixing Height
Daily Max 8-Hr Avg O3 at Boulder
- Elevated O3 when MH lt 150 m agl
- Note mini-SODAR max range 250 m agl
34Photos from Boulder Visibility Camera
35Typical characteristics of high ozone episodes
- Extensive snow cover, light winds, clear to
partly cloudy skies - Strong, surface based inversion
- Precursors trapped in very shallow layer (less
than about 150 m) - High morning NOx and VOC
- Limited horizontal mixing results in strong
spatial gradients - Morning NW to afternoon SE wind reversal
- Most common at Jonah also seen at other sites
- Highest ozone nearly always found at Boulder
lowest at Daniel and Cora in 2008
36Conditions Conducive to Ozone Formation
- The Three Ss
- Surface winds are light
- Snow cover is fairly complete
- Skies are clear to partly cloudy
- And more Ss
- Stable shallow surface layer with strong surface
inversion
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38Whats being done to reduce emissions associated
with oil and gas exploration and production?
39Ozone Precursor Sources
- Drill rigs
- Venting and Flaring from Well completion
activities - Gas production
- Vehicles
40Emission controls Rig Engines
- State has no authority to regulate non-road
sources - BLMs Jonah Infill Record of Decision enabled NOx
reductions improvements to rig natural gas
engines - BLMs Pinedale Anticline Record of Decision
requires operators to drastically reduce NOx
emissions
41Shells Nabors 784 Drill Rig
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43Insulated Urea storage tank used w/SCR to control
NOx emissions from the diesel generators.
Urea Tank
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46Cat 3512 (1500 HP each) Diesel Generator Stacks
w/SCR Note Typically all 3 generators operate
only during the drilling of the first 2,500 feet
of each well with 2 generators operating for the
rest of the drilling.
47Well Completion Emission Controls
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49Portable 4-Phase Completion Equipment
50Ozone Precursor Sources that DEQ Controls
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52Well Separator
53Dehydrator Pneumatic PumpControl Device
54Uncontrolled Condensate Produced Water Storage
Tanks
200 bbl storage tanks
55Multiple Well Facility
Dehy combustors
Tanks combustor
Dehy Contact Tower
Heater Stacks
56Immediate Response to the Ozone Challenge
- Preliminary conclusion is that VOC controls
should be the primary focus - Control existing uncontrolled sources by Jan 2009
- Increase inspections to look at all fields in
Sublette County - Voluntary reduction of VOC producing activities
during times when met. conditions appear
conducive to ozone formation
57Additional Responses
- Improve precursor emission inventories
- Revise oil gas best available control
technology (BACT) requirements - Interim offsets permitting policy
58Permitting New Sources
- AQD can no longer conclude that increases in NOx
and/or VOC in Sublette County can be justified - Interim permitting policy was implemented on July
21, 2008 - All applications will require a demonstration
that the proposed facility will not prevent
attainment or maintenance of an air quality
standard
59Interim Policy (cont.)
- Offset must be in Sublette County
- Offset must be enforceable, or approved by AQD
- Reductions must occur after 4/1/08
- Offset Ratios
- For applications currently under AQD review
- 11 offsets for NOx and VOCs
- For applications received after August 1, 2008
- Offset of 1.51 for VOC and 1.11 for NOx
- Currently are approximately 80 applications where
offsets are being discussed with AQD
60Upcoming Monitoring
- Continued operation of continuous monitors
- Move the Jonah monitor
- Adding a monitor in Pinedale operating in
November - Special winter monitoring in 2009
- AQD will conduct forecasting for winter of 2009
to inform public and operators
61Additional work
- Further VOC analysis
- Develop a full scale ambient ozone model
- Modeling is necessary to predict improvements
from emission reduction activities
62AQD Monitoring Site 4th high 8-hour ozone values
(ppm)
- These sites have 3 complete years of data for
2005-2007
63Ozone Non-attainment Implementation Timeline
- March 12, 2008 Final Rule signed
- May 27, 2008 Final Rule took effect
- March 12, 2009 State designation package (for
attainment/non-attainment areas) due to EPA - March 2010 EPA makes final designations on
attainment/non-attainment areas - 2013 Non-attainment SIPs due
64What will non-attainment mean
- Requests for new permits will be subject to new
requirements, which include offsets and Lowest
Achievable Emission Rate control requirements
for large sources currently, DEQ applies Best
Available Control Technology (BACT) to new
equipment. - NOx and VOC Controls for existing sources.
- Conformity determinations on all federal
actions places additional constraints on
federal agencies to conform with DEQs
nonattainment strategy. - There could be requirements imposed on
non-industrial sources as example is an
inspection and maintenance program for all
mobile sources in the area. - DEQ will need to devise requirements that will be
effective and make sense for the Upper Green.
These may look like what other states have done
or be entirely different. Ultimately emission
reduction requirements must demonstrate success
both through modeled attainment and acceptable
actual ozone levels at the monitors.