Frequent Questions

Is independent sampling and testing required of a refiner who has an in-line blending program?

Refiners who produce RFG using computer controlled in-line blending, and who have received an exemption from EPA from independent sampling and testing, are not required to conduct independent sampling and testing of RFG produced with this blending operation. The issues associated with in-line blending waivers from independent sampling and testing are discussed in the In-Line Blending Waivers Section of this document.

A refiner who produces RFG using in-line blending, but who does not have an exemption from independent sampling and testing from EPA, must meet the independent sampling and testing requirements. In such a case, however, EPA believes it is unlikely the refiner could meet all the requirements that apply to the production of RFG unless all the gasoline produced using the in-line blender is available for sampling and testing in storage tanks at the refinery before being shipped from the refinery. This tank collection gasoline is necessary so the refiner is able to meet the requirement that it have test results for a batch of RFG before releasing the RFG from the refinery. Tank collection also is necessary so the independent lab is able to collect a representative sample for the entire batch.

A sample collected by the refiner or by an independent lab at any single point in the blending process would not necessarily be representative of portions of that batch that were produced prior to, or subsequent to, the moment the independent sample was collected. As a result, a pipeline spot sample collected during an in-line blending operation would not satisfy the requirement that the refiner must have test results in advance of release of RFG unless the entire batch is held at the refinery until the refiner has in hand a test of the entire in-line blended batch. This entire batch sample could be a composite over the entire in-line blend, but more likely would be a sample from the storage tank, or storage tanks, where the in-line blended RFG is collected.

With regard to the independent sampling and testing requirement, conceivably the independent lab could collect a composite sample of the entire blend, but this would require the independent sampler to use its own compositor equipment, to be present during the entire blending operation in order to ensure the compositor functions properly, and to collect and analyze additional spot samples to verify the composite sample. In addition, the independent lab would have to independently establish the volume of the in-line blended batch. EPA is unaware of any valid way an independent lab can establish RFG batch volume, except through measurement in a storage tank.

As a result, EPA believes the only option available for a refiner using in-line blending to produce RFG who does not have an exemption from EPA from independent sampling and testing, is to collect the RFG produced using the in-line blender in a storage tank (or storage tanks) located on the refinery premises. The refiner then could certify the RFG in each storage tank as a batch, and have the independent lab collect a sample from each storage tank in the same manner as tank-blended RFG.(7/1/94)

This question and answer is posted at The original was posted in the Q&A posted on 7/1/94 which can found at" See Question ID 3857 for RFG (Taken from the first question on
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