1. November 14, 2003 Aboveground Storage Tank Enhanced Vapor Recovery

2. Below Grade Vaulted AST What is an AST? Aboveground Storage Tank: A system that uses a gasoline storage tank that is intended for fixed installations, without backfill, is located above or below grade and requires emergency relief venting.

3. Why Establish Regulations Specifically for ASTs? State Implementation Plan Leaks Testing Districts Consistency with EVR for USTs

4. 1000 Gal. Single Wall AST in Agricultural Community Various Types of ASTs

5. Covered Single Wall AST with Hirt Processor (4,000 gallon) Various Types of ASTs

6. 12,000 Gal. Protected Tank (double wall concrete) Various Types of ASTs

7. 15,000 Gal. Protected ASTs at Card Lock Facility Various Types of ASTs

8. Below-Grade Vaulted Tank: Definition: a storage tank that is intended for fixed installations, without back-fill, located underground in a vault, with continuous ventilation, and requires emergency relief venting.

9. How Many ASTs are Located in California? SOURCEPROTECTEDSINGLE TOTAL WALL REPORTED (in CA) APCDs/AQMDs----1,892 SWRCB----3,899 AST Manufacturers 3,5982,4076,005 *Fuel Carriers2,8734,7607,633 *Data used for staff report (represents a 16% response rate from fuel carriers). AST Inventory Comparison

10. Testing and Monitoring AST Testing and Monitoring –Conducted since July 2002 1,000, 2,000, 3,000, 6,000, 10,000 Gallon Insulated 1,000 Gallon Single-Walled Over 20 Pressure Decay Tests Conducted 3 Efficiency Phase I and Phase II Tests Conducted Results Indicated Fugitive Emissions Problem

11. AST Fugitive Emissions Pressure 2” 1” 0” 3” Tank gauge Em VentFill portVent pipeNozzle

12. Significant Leak Sources Emergency Vents –Subject to harsh environment –Not maintained properly –Some are metal-to-metal (no o-ring) Fuel Level Gauges –Plastic Gauges crack easily

13. Weighted Emergency Vent Cap Emergency Vent Cap with O-Ring Field conditions add to leak problems Significant Leak Source: Emergency Vent

14. Significant Leak Source: Plastic Fuel Level Gauges Plastic gauges tend to crack easily

15. Emissions Estimate PROTECTED SINGLE-WALLL TOTAL *AST INVENTORY 2,8734,760 7,633 **EMISSIONS (TPD) 1.86.0 >7.8 * Inventory based on fuel carrier survey **Estimate based on Data from Pressure Decay Tests Conducted

16. Proposed AST Changes Reduce Allowable AST Leakrate 180-Day Field Certification Test Nozzle Performance Criteria Standardization of Fuel Delivery Adaptors Establish Pressure Profile of -0.5 in WC

17. Estimated Emissions Reduction AST Type: Protected Single Wall Total AST’s in California 2,873 4,760 7,633 *Em. Reduction Range.81 to 1.62 2.8 to 5.7 3.6 to 7.3 (TPD) * upper limit assumes 95% reduction if 100% of AST’s in inventory will be modified to new standard.

18. Cost Effectiveness Estimate Cost Effectiveness = _ Annualized Cost. Annual emission reductions statewide Protected Single Wall Total ($) / lb 2.491.751.91 For Comparison - UST EVR :$5.24/lb

19. Proposed Effective Date SIP Lawsuit Settlement Requires a Hearing Notice and Staff Report Release Date of December 2003 Effective Date of Measure: –December 31, 2006 for New Installations –December 31, 2010 for Existing ASTs Subject to Vapor Recovery

20. Major Modifications ASTs which are upgraded after December 31, 2006 are considered a major modifications if the tank is replaced – this will trigger Phase I and Phase II EVR requirements for the system

21. Schedule Staff Report : December 2003 Next Workshop: January 2004 Board Meeting: February 2004

22. Contact Stephanie Connelly Monitoring and Laboratory Division California Air Resources Board P.O. Box 2815 Sacramento, CA 95812 (916) 445-9308 saconnel@arb.ca.gov www.arb.ca.gov/vapor/ast/ast.htm