UnitedStatesEnvironmentalProtectionAgency,RegionIXAir&ToxicsDivisionTechnicalSupportDocumentforEPA’sNoticeofDirectFinalRulemakingfortheArizonaStateImplementationPlanArizonaDepartmentofWeightsandMeasuresArizonaAdministrativeCodeTitle4,Chapter31,Article9GasolineVaporControlMaeWangJuly21,1994Agency Name: Arizona Department
of Weights and Measures (ADWM) Submitted Rule Number: Arizona Administrative Code (AAC) Title 4, Chapter Rule

31, Article

9 (contains R4-31-901 through R4-31-910) Title: Gasoline Vapor Control Submittal Date: May 27, 1994 District Adoption Date: August 27, 1993 Applicable Rule Number: no applicable SIP rule Sip Background: The EPA made

a finding of nonsubmittal

on January 15, 1993 for stage II vapor recovery rules from the Phoenix (Maricopa County) non-attainment area. This submittal stops the 18 month sanctions clock associated with that finding, and must be approved by EPA within 24 months of the finding in order to avoid imposition
of aFederal Implementation Plan. Section

1 82(b)(3) of the Clean Air Act, as amended
in 1990, requires gasoline dispensing facilities located
in nonattainment areas designated

as moderate
or worse to install and operate stage II vapor recovery equipment. The State of Arizona has included this requirement into the Arizona Revised Statutes (ARS), section 41-21 32, and it applies to the Phoenix nonattainment area. Article

9 of the AAC sets out the standards for any required stage II systems. Summary
of Rule: The Article

9 regulation controls the emissions of volatile organic compounds (VOCs) during the transfer of gasoline into motor vehicle fuel tanks. The rules require useof CARB certified stage II systems, and inspection and maintenance
of equipment. The following are the major provisions
of the regulation:-Prior to installation, modification

or initial operation,

a construction plan for stage II vapor recovery systems must be submitted for approval.-Initial compliance tests and inspections must be performed.-The stage
11 systems and components must be operated and maintained

in a vapor-tight and leak-free condition.-The systems and components must be inspected daily for defects, and daily records of inspections are to be kept. Rule Evaluation and Proposed Action: This rule was evaluated against the EPA draft model rule for Stage
11 vapor recovery, and various guidance documents including the document entitled “Issues Relating
to VOC Arizona Stage

11

2Regulation Cutpoints, Deficiencies, and Deviations: Clarification

to Appendix

D of November 24, 1987 Federal Register, May 25, 1988. Strengthening Areas Since there is no existing SIP rule for this category, the regulation strengthens the SIP by requiring Stage II vapor recovery controls for gasoline dispensing facilities. Appendix D/RACT Deficiencies No Appendix D/RACT Deficiencies are noted. Other Areas The following issues are not considered significant enough
to affect the approvability of this regulation, hut they should be addressed
in the next rule revision. a) The regulation could be strengthened

if the term “monthly throughput’ was defined ona 30-day rolling average rather than ona calendar month period. b) Although the terms “liquid-tight” and “vapor-tight”
are defined, the term “leak-free” is used in section R4-31-906.B. The regulation could be clarified
if “leak-free” weredefined in reference
to “liquid-tight” and “vapor-tight”. 2. Net Effect on Emissions Although there have been emergency stage II rules in effect in Arizona, the incorporation

of this regulation into the SIP will decrease emissions based on the current SIP since there is no existing SIP rule for this category. 3. Proposed Action EPA is proposing

to approve AAC Title 4, Chapter 31, Article
9. Attachments: 1. Article
9, Gasoline Vapor Control. 2. Arizona Revised Statutes relating
to stage II vapor control. 3. EPA comment letter, dated October 28, 1992. 4. EPA comment letter, dated May 5, 1993. Arizona Stage
II

3