EPA’s Proposed Revision of the SO2 NAAQS &

AQD’s Subchapter 31 – Control of Emissions of Sulfur

Presentation to the Air Quality Advisory CouncilJanuary 20, 2010

Subchapter 31Control of Emissions of Sulfur

• OSDH Rule First Effective in July 1972– Ambient SOX/SO2 Standards for Existing Facilities

• Current Subsection 100-31-7(a)• Also Applies to Petroleum & Natural Gas Processing Facilities Built

After December 1974 – SO2 Emissions Limits for Certain “New”

Facilities/Equipment• Fuel-burning equipment• Sulfur Recovery Plants• Nonferrous Smelters • Paper Pulp Mills

– SO2 and Sulfuric Acid Mist Emissions Limits for “New” Sulfuric Acid Plants

Last Proposal

• Clarify Language• Require New & Existing Sources to Meet the

Same Requirements– Subsection 100-31-7(a)– Suggested Dropping 5-minute Standard

• Add “Alternative Fuels” Definition and Requirements

EPA’s Proposed SO2 NAAQS Revision

• Published on December 8, 2009– 74 FR 64810

• Moves Focus to Minimizing Exposure to High Short-Term Concentrations

• Info at:– http://www.epa.gov/air/sulfurdioxide/actions.html

EPA’s Proposed SO2 NAAQS Revision

• Primary Standard Only– Effects on Human Health

• Separate Review for Secondary Standard – Due by 2012– Effects on Welfare– Deposition of SO2 & NOX

• High SO2 => High SOX (PM2.5 Precursor)

Standard: Current vs. Proposed

• Current SO2 NAAQS:– 24-hour 140 ppb– Annual 30 ppb

• Proposed SO2 NAAQS :– 1-hour 50 – 100 ppb• Revoke Both the Current 24-hour& Annual Standards

SO2: Current vs. Proposed NAAQS vs. SC31

Current Standards (App. E & F)

EPA’s Proposed Revision(74 FR 4810, 12/8/09)

SC 31 Requirements

Primary Secondary Primary Alternative Primary

(252:100-31-7)

5-Minute 500 ppb

1-Hour 50 – 100 ppb 150 ppb 460 ppb

3-Hour 500 ppb 250 ppb

24-Hour 140 ppb Delete140 ppb (Retain)

50 ppb

Annual 30 ppb Delete Delete 30 ppb

http://www.epa.gov/air/sulfurdioxide/actions.html

Attainment: Current vs. Proposed

• Current:– Oklahoma is in Attainment for Current Standards

• Proposed (EPA Projection):– Tulsa & Muskogee Counties would be Non-

Attainment at 50 ppb Level

Final Rule Issued by June 2, 2010

• Comment Period Closes February 8, 2010

Proposed SO2 Monitoring

• All Monitoring Sites – “Source-Oriented”– Measure Maximum Ground-Level Concentrations

• 348 Sites Planned Nationally– 231 – “Core Based Statistical Areas”• Based on Population & SO2 Emissions

– 117 – State’s Contribution to National Emissions• State Determines Locations

– Operational by January 1, 2013

Current SO2 Monitoring

• 448 Current Active Monitoring Sites Nationally– 1/3 (~163) Sited “Correctly”– ~185 New (or Relocated?)

SO2 Monitoring in Oklahoma

• 7 Current SO2 Monitoring Sites– Most are Source-based

• EPA Proposal Would Require:– One State-Level Emission-Triggered Monitor – Two Population-Oriented Monitors• Tulsa

• AQD Would Review Monitor Locations

Implementation TimelineMilestone Date

Signature – Final Rule June 2, 2010

State Designation Recommendations to EPA June 2011

Final Designations June 2012

SIPs Due Winter 2014

Attainment Date Summer 2017