The district uses about 200,000 gallons of diesel a year, so the extra 20 cents it costs to buy each gallon of ULSD adds up to $40,000 of new costs. By buying diesel in bulk with other school districts in the Allegheny Intermediate Unit, the cost goes down, but obviously it's still higher than messy old diesel. Adding expensive filters or diesel catalytic converters (at about $150 per bus) also cleans the air the children breathe. The Penn Hills School District says it spent more than $12,000 for converters for the district's 83 buses. They're doing it for the children.
[Source: Pittsburgh Tribune-Review]