Hydrogen Sulfide Monitoring at an Oil Field in Southern Illinois

1. Hydrogen Sulfide Monitoring at an Oil Field in Southern Illinois Kathryn Siegel, Bonnie Weinbach National Air Quality Conference Portland, Oregon April 9, 2008

2. EPA began receiving complaints… • Significant odors – “rotten egg” odors • Headaches, vomiting, nausea, grogginess, watering eyes, sleeplessness, fainting, difficulty breathing, sinus problems, asthma, bronchitis, heart problems, skin rashes, allergies, and seizures • Damaged equipment • Emergency room visits

3. PennTex Resources Illinois, Inc. • Located in Bridgeport, Illinois • Population: 2,200 • 2006 marked the 100th year of oil production • Own and operate 900 oil production wells and about 20 gathering facilities in Lawrence County

5. Sour Gas • At a well, as oil is produced, natural gas is displaced and emitted from the wellhead • In the Lawrence Field, very little gas is produced • Gas that is produced is not collected and sold • When gas was produced, the company attempted to eliminate it by flare • Gas is sour – high sulfur content

6. Wells

7. Barrel Flare

8. Tanks at Gathering Facilities

9. Emergency Pits

10. Loading Operations

11. Oil Spill

12. Oil Spill – “Clean-Up”

13. Preliminary Results

14. H2S -- Health Effects Respiratory and Central Nervous Systems • Headache, poor attention span, impaired motor function • Dizziness, nausea, poor memory, loss of sense of smell • Sore throat, cough, impaired lung function in asthmatics • HIGH CONC: Loss of Consciousness (> 500,000 ppb)

15. EPA Actions • First Consent Decree filed under the imminent and substantial endangerment provisions of the Clean Air Act (Section 303) • Ambient Concentration Screening Level of 70 ppb over 30 minutes and 20 ppb over 15-day average • H2S emissions reduced by approximately 50 Tons per year • Controls installed summer 2007 • Completion of controls expected end of the year

16. PennTex’s Control Strategy • Sour gas is routed from well to an elevated central flare • Tanks are vented to an elevated central flare • Implemented an automatic shutdown system, virtually eliminating the usage of the emergency pits • Emissions from loading operations are sent to elevated flare • Some emergency pits are covered Elevated Flare

17. Air Monitoring Network

18. Monitoring Overview • Began summer 2006 • 7 EPA sites • Current Network • 4 H2S sites • 2 SO2 sites • 1 met station

19. Active Wells, Gathering Facilities & Monitoring Sites MAP REMOVED FOR CONFIDENTIALITY

20. Site 1: inlet

21. Site 1: Trailer

22. Site 3: H2S and SO2 Analyzers

23. Met Station

24. Data Analysis

25. H2S Concentration by Time

26. H2S versus Wind Speed (Site 1)

28. Elevated flare installed

29. Elevated flare installed

30. Elevated flare installed

33. Pollution Roses

34. Infrared Camera Video Footage

35. Receiver Tank

36. Relief Valve

37. Conclusion • EPA will continue to monitor through Spring 2010 • Biggest air monitoring network and longest air monitoring project led by R5 • R5 purchased a new H2S ambient monitor, wireless modems and an Infrared Camera • Reduced number of complaints • Citizens are breathing cleaner air

38. Thank You Lawrence County Health Department From U.S. EPA R5: Enforcement, Office of Regional Counsel, Superfund, Water Headquarters Region 7 Illinois Department of Natural ResourcesOffice of Mines and Minerals