Focus on TUSD - June 2007

Setting the Standard:
TUSD's Bus Fleet and Operation Tops the Clean List
TUSD may have the cleanest school bus fleet and operation in the country. If it doesn't, it's not for lack of trying. Bill Ball, director of the Transportation Department said TUSD's environmental strategies are "green for both the environment and the pocketbook."

An article in the April 2007 Diesel Progress publication detailed TUSD's journey toward converting its buses to low emission vehicles and investing in alternative fuels and emissions control devices. Over a three year-period, TUSD received $2.1 million in grants to help finance these changes. Voters also approved a $4.5 million bond to help the District meet its goal of providing cleaner and safer school buses.

TUSD was one of only three school districts to receive a $75,000 award from Caterpillar Inc. through the U.S. Environmental Protection Agency in 2004. That money allowed the District to retrofit 75 school busses with Caterpillar diesel oxidation catalysts.

"We bypassed buses we would retire inside of five years," Ball said. "We put them on the dirtiest 75 that we would have for at least 10 more years."

The TUSD bus fleet has 319 International, Blue Bird and Thomas buses dating from 1979 to 2006, which have diesel engines. The fleet also features a dozen compressed natural gas buses. To help purchase buses with CNG in the future, the U.S. Department of Energy gave TUSD a $200,000 grant through EPA. Adding the CNG-powered buses has helped save the District money, Ball said. He estimated that there is a 60 to 66 cents savings per equivalent gallon using CNG instead of diesel.

If the Governing Board approves the purchases, within the year, 80 new CNG and Tier 3 diesel school buses will be added to the fleet, Ball said. Funding will come partially from an Arizona Department of Environmental Quality grant totaling $1.36 million. This grant is part of the ADEQ's Low Emission School Bus Program, which awarded TUSD its largest grant.
The $1.36 million award earmarks $385,000 to help purchase 11 new CNG-powered buses, while $630,000 will go toward buying 42 new ULSD-fueled buses. The remaining $354,144 will be dedicated to diesel particulate filter retrofits on 38 of the oldest buses.

The ADEQ grant came on the heels of a grant from the EPA's Clean School Bus USA program. Awarded in February 2006, the EPA grant is intended to provide TUSD with $493,000 to offset the purchase of 19 CNG-powered school buses, taking the District's CNG bus total to 50.

Even though TUSD received its grant funding in 2006, Ball said, "We're ordering all engines that meet 2007 standards so we've received an extension on the grant deadline, allowing for the cleanest buses possible. We simply stated that we had to hold the grant over in order to do this. It took a little extra paperwork, but it made prefect sense."

TUSD also receives additional money to purchase cleaner and newer buses through "sponsored positive messaging" billboard advertising on its school buses. "With bus advertising, we're bringing in even more funding," Ball said. "Every cent goes to either paying for higher cost, cleaner engines, more expensive cleaner fuels, engine additives or retrofits for particulate traps and diesel oxidation catalysts."

Besides new buses and retrofits, TUSD's newest emissions reduction program affects vehicles pulling up to the district schools. The Idle Reduction Program mandates that engines must be turned off within five minutes of arriving at the school and cannot be turned back on until the vehicle leaves.

In Tucson, this process is complicated by hot temperatures. Tucson area temperatures regularly top 100 degrees several months of the year. "Turning engines off in the summer months is not always practical," Ball said. "This conflicts with the District's air conditioning requirement for all schools and school buses. All of our buses are now bought with an RV-style refrigeration unit so the driver can turn off the main engine when loading, unloading or waiting and still provide cooling."

He said that the generator uses considerably less fuel when run separately from the main engine.

In addition to running generator-powered air conditioning on the buses, TUSD has been experimenting with a Viesa evaporative cooler on several vehicles. This system is half the price of air conditioning and doesn't require using an engine for power, Ball said. Driven through the vehicle's electrical system, it pulls cooling from water tanks located behind the rear wheels.

Painting the bus roofs white has also reduced the buses' interior temperatures. Tinted windows are a standard feature on every bus, helping reduce temperatures inside by as much as 14 degrees, Ball said.

Many of these modifications are completed at one of the Transportation Department's two locations in eastern and central Tucson. At these places, TUSD services engines, performs daily checks and uses an in-house dynamometer for emissions testing. Two complete fueling stations are available, offering ULSD, gasoline, biodiesel and E85, which the District is using on its newer service vehicles. In total, the department maintains 710 vehicles, including school buses, driver's education cars, conversion vans and maintenance trucks.

The Transportation Department is also testing the global positioning satellite system on the buses, allowing the district to analyze overall bus use, Ball said. "It provides data on acceleration, turning speed, and braking, conserving tires, fuel and following the shortest possible course of travel," he explained. "When you're doing all that, you're minimizing both pollution and cost."

GPS could provide TUSD additional monitoring on bus locations, on whether a passenger has been dropped off, or on any deviation from a planned route.

Route planning is another factor in TUSD's emissions reduction plan, which it optimizes through Educational Logistics' computerized routing program. "We can test mathematically the very shortest and quickest way to get anywhere," Ball said. "This provides us with routes that are the most efficient possible for both student and drivers."

All of TUSD's 104 schools have staggered start and end times to the school day to minimize the number of buses used. Transfer points and combination routes are also used to help improve fuel usage and route mileage.

Bus routes will also be more efficient when the department's newest facility, scheduled for completion in August 2008 is ready. With the new west side location, TUSD will have facilities on the east, west and center of Tucson, which Ball said, "is the last step in minimizing unnecessary mileage. Currently, to travel to most west-side schools, buses have a half-hour of driving each way, up to three times a day without students," he said. "We're using fuel and time with no service component."

He estimated the new facility will cut this time down to about 10 minutes each way, which will save energy and time, conserve limited funding and reduce pollution.
The new west-side facility will mirror TUSD's main location in the center of the district. Maintenance will be provided on-site and one-third of TUSD's bus fleet will operate from the new location.

TUSD Transportation - By the Numbers

-- By Sharon Dunham
Communications & Media Relations

TUSD - Proud Supporter of Small Classes

All photos in the June issue by Jes Ruvalcaba of Communications & Media Relations.

The deadline to submit material for the August Focus is Friday, August 3. The Focus will be published Monday, August 13. Email submissions to Chyrl Hill Lander or Sharon Dunham in the Communications & Media Relations Department or use the Focus Online Submission Form.