California Air Resources Board and the State Water Resources Control Board issued a joint statement July 31 to clarify questions raised over the status of renewable diesel, including storing the biomass-based diesel in underground storage tanks.

“We consider renewable diesel to be a ‘drop-in’ fuel that can be blended with conventional CARB diesel in any amount and used with existing infrastructure and diesel engines,” the statement said. “Accordingly, renewable diesel that meets the requirements for conventional CARB diesel and ASTM D975-12a should be treated no differently than conventional CARB diesel that is legal for sale in California.” This includes same treatment for storage in underground tanks, quelling concerns about the compatibility of renewable diesel with leak detection systems used in underground storage tanks storing conventional CARB diesel.

The statement included an attachment comparing several renewable diesel samples to conventional CARB diesel under the petroleum diesel spec, ASTM D975-12a. “Both the tested conventional CARB diesel and renewable diesel samples fall well within the ASTM D975-12a specifications,” the statement said.

Click here to view the statement and fuel sample comparisons.