Where PTDs account for all product and show the product is in compliance with the diesel standards, and where the pumps are properly labeled, and the retailer or wholesale purchaser-consumer has not caused the violation, (e.g., has not misdirected noncomplying product into the 15 ppm diesel fuel storage tank or otherwise caused the contamination or misdelivery to occur) it will generally be able to establish its defense to liability.
However, if for example, a retailer or wholesale purchaser-consumer were to purchase fuel that it has reason to believe does not comply with the 15 ppm sulfur standard, even though the PTDs account for all product and state that the product does meet the standard, the retailer would be liable since it would have caused the violation.
Question and Answer was originally posted at Questions and Answers on the Clean Diesel Fuel Rules (PDF)(135 pp, 888 K, EPA420-B-06-010, July 2006, About PDF)