A bill that would have required Phoenix's diesel fuel to meet California's cleaner diesel standards has been put on hold.

According to The Arizona Republic, the bill's sponsor, House Majority Leader Carolyn Allen, pulled the legislation because she doesn't have time to push the controversial measure at the same time as budget negotiations.
This means it will be at least a year before the state's Legislature considers the bills, some of several designed to clean up the area's "Brown Cloud" of pollution.
HB2449 would have required any diesel fuel sold in the Phoenix area after April 2003 to meet California's higher standards (often called "CARB" fuel after the California Air Resources Board).
A 1999 report indicated that diesel exhaust was the main reason for the area's pollution problems.