Tanker Truck Certification (Vapor Recovery)

Rule 352, "Gasoline Delivery Vessel Testing and Use", of the Maricopa County Air Pollution Control Regulations states that "no person shall store or transport gasoline in or otherwise use or operate any gasoline delivery vessel unless such vessel is designed and maintained to be vapor tight and leak free".

To comply with this requirement, a gasoline delivery vessel shall first pass the Maricopa County Pressure Test before delivering or onloading gasoline, and must pass the test each year thereafter.

All testing done within Maricopa County must comply with Section 401.1 concerning notification of test time and date. Notification of testing can be done through the online notification form.


Maricopa County Pressure Test



The Maricopa County Pressure Test consists of three subtests:

  • Positive Pressure Subtest
  • Vapor Valve Subtest
  • Partial Vacuum Subtest
The vessel must pass all three subtests, in the order presented, in the same testing period. See Rule 352 for details of testing procedures and parameters.

Application for Vapor Recovery Certification


Details and results from each subtest shall be entered onto the Tank Truck Leak Certification Checklist (PDF), which is then submitted with a complete application to the Air Quality Department. A complete application consists of:

The decal that certifies test completion will be issued by the Control Officer usually within 3 business days of receipt of a complete application. The expiration date of the issued decal is dependent on the testing date. Refer to Section 401.3 for expiration dates.