The Superior school district is trading in problems for opportunities.

Transportation director Chad Jensema informed the Superior School Board at its March 6 meeting that plans are underway to trade in four 2009 buses for two new propane-fueled units.

The four buses, Bluebirds with Caterpillar engines, have not been in use since failing to meet emissions standards more than a year ago.

Jensema had been working with Cummins Inc. to find a potential fix, but replacing the Caterpillar engines proved unfeasible - leaving a trade-in as the best option to recoup value from the buses.

"And it will provide us an opportunity to get some propane units," Jensema said.

That prospect drew interest from several Board members.

Propane buses emit fewer greenhouse gases than diesel buses and have gained popularity as a "greener" alternative. Fueling costs are typically lower than for diesel buses.

Robert Morehouse, treasurer of the Superior School Board, questioned the reliability of propane buses during northern Wisconsin's harsh winters.

Jensema said propane buses are ideally suited for cold climates and actually outperform their diesel counterparts in several areas.

Propane buses have been shown to start more reliably in cold weather, and they provide heat to passengers faster and more consistently.

The school district will be seeking bids for the new propane buses this month, and the matter will be brought before the School Board for approval in April.

In other business:

• At its March 6 meeting, the Board also approved nearly $175,000 in bids for security upgrades at Superior Middle School. All work was awarded to companies based in either Duluth or Superior.

• The Board voted 5-0 in favor of the motion. Members Mary Klun and Mike Raunio were absent.

• To date, school district administrator Janna Stevens said roughly $9.5 million of the total $92.5 million referendum has been paid for work completed. She expects that total to rise significantly in the coming months as work begins on the Superior High School and Cooper Elementary School projects.

• Stevens also reported better-than-expected interest earnings on two series of bonds issued last year for the referendum. The combined anticipated earnings had been close to $800,000, but the estimate has now risen to $850,000.

• The School Board also approved staffing levels for the 2017-18 school year at its regular meeting Monday. Members voted to keep administration positions the same at 29 full-time employees. For instructional staff, the Board approved an increase of two FTE due to high anticipated elementary school enrollment. One new position will go to Lake Superior Elementary School, and the other will go to Great Lakes Elementary School. Both schools expect increased fourth-grade enrollment, and Great Lakes may also have high third-grade enrollment.