EPA will consider extreme circumstances that may prohibit sampling and testing as required by section 80.69. However, to date, EPA is not aware of such circumstances.
Some state laws may prohibit the opening of truck compartment hatches during loading, unloading and transport operations. Certainly, sampling should not be conducted during these operations. In order to obtain a representative sample with certainty, the transport vehicle must be driven through a series of starts, stops and turns, so that complete mixing will occur. Safety procedures require that transport vehicles are parked for a period of time prior to sampling, to allow electrostatic charges to dissipate, and vapor pressure to stabilize. Only after this stabilization period are the hatches opened. Therefore, hatch opening will not occur during loading, unloading or transport, and subsequently will not result in significant VOC emissions.
For personal safety reasons as well as the increased amount of work required, sampling truck compartments under section 80.69 should be conducted when retail tank sampling is not appropriate under § 80.69(e)(2)(i)(B). However, if truck sampling is required, the sample collector can confirm with the truck driver whether or not the truck is empty prior to loading. If there is reason to confirm by inspecting the compartments to be sampled, that could also be performed prior to loading. The normal heel of the truck compartments after a complete unloading is not enough product to significantly alter the new load.
A quality assurance program consisting of meter readings and RBOB quality at the distributor level leaves out the question of oxygenate blendstock quality. As a result, a quality assurance program must use samples of RFG produced subsequent to the addition of oxygenate.
EPA inspections will occur both at the retail level, and at the terminal level. In the case of splash blended oxygenate, EPA primarily will rely on samples collected at the retail level, but may collect samples from delivery trucks on occasion.(8/29/94)
This question and answer was posted at Consolidated List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (PDF)(333 pp, 18.17 MB, EPA420-R-03-009, July 2003, About PDF)