On March 25, 1999, Governor Gray Davis released Executive Order D-5-99 that ordered the removal of the additive MTBE (Methyl Tertiary-Butyl Ether) from gasoline at the earliest possible date, but not later than December 31, 2002.

The Governor also directed the California Energy Commission to evaluate and report to the Governor and the Secretary for Environmental Protection on the potential for development of a California waste-based or other biomass ethanol industry. The Commission was directed to "...evaluate what steps, if any, would be appropriate to foster waste-based or other biomass ethanol development in California should ethanol be found to be an acceptable substitute for MTBE."

California Energy Commission's MTBE Study Web Site