The definition of "refiner" includes any person who owns, leases, operates, controls or supervises a refinery. Therefore, under this scenario, both the person who owns the gasoline being blended, and the person who owns the terminal tanks would be considered to be refiners.
Each person meeting the definition of refiner for a particular refinery operation is independently responsible for the completion of all refinery requirements, such as meeting standards, sampling and testing (including independent sampling and testing), record keeping, reporting, and independent audits. However, these refinery requirements must be met only once for any refinery operation. As a result, if the refinery requirements are properly accomplished by one "refiner" for a particular refinery operation, EPA will consider the requirement to have been accomplished by each person who meets the definition of refiner for that operation.
In the scenario described in the question, Company A could rely on Company B to meet the requirements for that refinery operation. If Company B does not properly meet all the refinery requirements, however, both Company B and Company A would be independently liable for the violation. As a result, Company A should allow Company B to conduct a refinery operation at Company A's facility only if: (1) Company A intends to meet the refinery requirements for the operation; or (2) Company A is fully satisfied Company B will meet these requirements. In addition, should Company A rely on Company B to meet these requirements, Company A should monitor the operation to ensure Company B in fact meets all refinery requirements.(7/1/94)
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)