Section 80.78(a) requires the segregation of several categories of gasoline. These categories are:
RFG may not be mixed with conventional gasoline, and sold or used as RFG.

RFG blendstock for oxygenate blending (RBOB) may not be mixed with RFG or conventional gasoline, and RBOB's that have different oxygen requirements must be segregated from each other.

During the period January 1 through September 15 each year VOC-controlled RFG that is produced using ethanol must be segregated from VOC-controlled RFG that is produced using any other oxygenate, including at the retail level.

Oxygenated fuels program RFG (OPRG) must be segregated from non-OPRG designated RFG(unless the OPRG contains a minimum of 2.0 wt% oxygen).

Upstream of the retail level, RFG produced under the simple model may not be mixed with RFG produced under the complex model.

Before January 1, 1998 each refinery's or importer's complex model RFG must be segregated from every other refinery's or importer's complex model RFG, unless the refineries or importers have identical baselines. This segregation requirement does apply at the retail level.

These segregation requirements preclude the mixing of any amount of the gasolines that must be segregated. For a discussion of the handling of the heal of a tank at terminals, see question 4 of the transition section.

Section 80.78(a)(1)(v) requires that RFG must be VOC-controlled for the proper VOC-control Region when stored or dispensed by terminals beginning May 1 of each year, and for retail outlets and wholesale purchaser-consumers beginning June 1 of each year. As a result, parties in the gasoline distribution system must transition from non-VOC-controlled RFG to VOC-controlled RFG in advance of these dates.

The RFG regulations contain no prohibition against combining VOC-controlled RFG with non-VOC-controlled RFG. As a result, VOC-controlled RFG may be added to a storage tank that contain non-VOC-controlled RFG in order to turn over the storage tank to the VOC-controlled specification, in advance of May 1 each year in the case of terminals, and in advance of June 1 each year in the case of retail outlets and wholesale purchaser-consumers.

A party who combines VOC-controlled and non-VOC-controlled RFG should treat the mixture as a downgrade to non-VOC-controlled until the party has a test result that shows the RFG meets all applicable VOC-controlled RFG standards. A terminal, therefore, should not supply product transfer documents to distributors stating the gasoline is VOC-controlled until the terminal has a test result that would support this designation.(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)