Ariz. Rev. Stat. § 49-573 – Emissions controls; federal vehicles

A. The operator of a United States government owned vehicle fleet based primarily in this state shall develop and implement a vehicle fleet plan for the purpose of encouraging and progressively increasing the use of alternative fuels and clean burning fuels in United States government owned vehicles. The plan shall include a timetable for increasing the use of alternative fuels and clean burning fuels in fleet vehicles either through purchase or conversion.
B. The timetable shall reflect the following schedule and percentage of vehicles that operate on alternative fuels and clean burning fuels:
1. 1. At least ten per cent of the total fleet by December 31, 1994.
2. 2. At least forty per cent of the total fleet by December 31, 1995.
3. 3. For fleets operating primarily in counties with a population of more than one million two hundred thousand persons according to the most recent United States decennial census, at least ninety per cent of the total fleet by December 31, 1997 and each year thereafter.
C. The requirements of subsections A and B of this section may be waived on receipt of certification supported by evidence acceptable to the department of environmental quality that the United States government fleet operator is unable to acquire or be provided equipment or refueling facilities necessary to operate vehicles using alternative fuels or clean burning fuels at a projected cost that is reasonably expected to result in net costs of no greater than thirty per cent more than the net costs associated with the continued use of conventional gasoline or diesel fuels measured over the expected useful life of the equipment or facilities supplied. An entity that receives a waiver pursuant to this section shall retrofit fleet heavy-duty diesel vehicles with a gross vehicle weight of eight thousand five hundred pounds or more, that were manufactured in or before model year 1993 and that are the subject of the waiver with a technology that is effective at reducing particulate emissions at least twenty-five per cent or more and that has been approved by the United States environmental protection agency pursuant to the urban bus engine retrofit/rebuild program. The entity shall comply with the implementation schedule pursuant to section 49-555.
D. If the requirements of subsections A and B of this section are met by the use of clean burning fuel, vehicle equivalents under those requirements shall be calculated as follows:
1. 1. One vehicle equivalent for every four hundred fifty gallons of neat biodiesel or two thousand two hundred fifty gallons of a diesel fuel substitute prescribed in section 1-215, paragraph 7, subdivision (b).
2. 2. One vehicle equivalent for every five hundred thirty gallons of the fuel prescribed in section 1-215, paragraph 7, subdivision (d).