One new $970,000 fire truck is on the way, but whether the city will fulfill a 2008 campaign plan to buy a whole fleet of the shiny new machines is less certain.

Lawrence city commissioners at their Tuesday meeting unanimously approved a $972,525 bid for a new Pierce quint fire engine. The new fire truck is the fourth new fire engine commissioners have approved since voters passed a 2008 infrastructure sales tax that was sold to voters, in part, with the idea that $500,000 a year for the next 10 years would be set aside for fire truck purchases.

But as commissioners approved their latest fire truck purchase on Tuesday, they were reminded that plan has now changed.

As part of the 2012 budget, commissioners approved a re-shuffling of the multi-year spending plan for the 0.3 percent infrastructure sales tax approved by voters in 2008. Under the new plan, just $600,000 will be set aside for fire truck purchases between 2013 and 2018 — or, in other words, about $2.4 million less than what was anticipated when voters approved the sales tax. Much of the money once planned for fire equipment is scheduled to go to increased street maintenance.

“I think we really just have been trying to balance the needs of the community,” said City Commissioner Mike Dever. “I think we have done a good job of adhering to the plan. I think it was always clear to people that the plan was to be aggressive with improving the condition of the roads.”

City leaders, though, still think more fire trucks will be on the way.

“I think we’re still on track to meet our goals,” said City Manager David Corliss. “We’re still on track to do it, but we may have to stretch it out a little farther.”

The original sales tax plan called for 10 new pieces of fire equipment to be purchased over the 10-year life of the sales tax. Officially, the plan still calls for that. But Corliss said some of the purchases may have to be pushed past the 10-year time period, and very likely the city will have to issue more general obligation debt than envisioned during the campaign.

Corliss, though, said the city does have flexibility to issue more debt for fire engines, in part because the city’s bond and interest fund has a significant reserve fund that gives the city some ability to issue new debt without raising property taxes.

At the end of 2011, the city’s bond and interest fund had a fund balance of about $8.49 million, and in 2012 the city was able to budget $13.8 million in new general obligation debt — mainly for improvements to the former Farmland Industries site and for infrastructure for a proposed recreation complex — without raising property taxes.

The city has a Sales Tax Audit Committee that annually reviews whether the city is spending the sales tax money in accordance with the ballot language approved by voters. Thus far none of the changes to the spending plan has raised an issue because the ballot language doesn’t obligate the city to spend any specific amount of money on particular types of projects. Instead, the ballot language simply mandates that all the money be spent on projects that fall within the infrastructure category.

In other news, commissioners:

l Unanimously approved a 40-year water treatment contract with the city of Baldwin City. The contract will continue to allow Baldwin City to have its water treated at Lawrence’s water treatment plants. The contract sets a new wholesale water rate that is about 25 percent less than the current wholesale water rate charged by Lawrence.

l Rejected on a 4-1 vote a request to establish a mid-block crosswalk in the 700 block of New Hampshire Street. Mayor Bob Schumm urged commissioners to consider the mid-block crossing, especially to accommodate pedestrians who will be walking to the temporary location for the library, which will be in the former Borders building at Seventh and New Hampshire streets. But commissioners were told the design of the mid-block crossing likely would cause nine parking spaces along the street to be lost.