BATH — With about $1.6 million at stake, the city is joining Regional School Unit 1 in its defense of a lawsuit filed by fellow school district member West Bath.

After a hearing Tuesday in Sagadahoc County Superior Court, Justice Andrew Horton decided to allow Bath to intervene in the case, according to Patrick Scully, an attorney representing the city in the matter.

West Bath is suing RSU 1  – which also includes Arrowsic, Phippsburg and Woolwich – to recover $1.9 million the town believes it overpaid in the first four years of the school district’s existence.

West Bath’s lawsuit, filed last October, claims it should have been assessed a total of $8.2 million in fiscal years 2008, 2009, 2010 and 2011, but instead paid $10.1 million.

The suit claims RSU 1 owes West Bath $1.9 million, plus interest. Both RSU 1 and Bath have filed motions to dismiss the case, Scully said.

“They’re suing the RSU, but the RSU has no ability to raise money to pay a judgement, if there were a judgement against them,” he said. “If West Bath were ever to prevail, the only way that money would be obtained would be if the RSU turned around and ordered its other members to pay up.”

He noted that most of that money – roughly $1.6 million – would come from Bath, the largest member of the school district.

The matter “is essentially the same as West Bath suing Bath directly; that’s effectively what’s happening here. It’s just through the shell of the RSU,” Scully explained.

“We believe there are a lot of reasons why (West Bath) should not prevail, and why their claim is without merit” he said, “but we have to actually be in the case to present those arguments.”

The RSU 1 Board of Directors unanimously approved a new cost-sharing formula last month that could go into effect this year. The change must be approved by a district-wide referendum, which could be held in March.

The board had voted unanimously April 23 to change the cost-sharing formula for the current, fiscal 2013 budget, so that a law that created the school district would apply to its entire local tax calculation.

The local contribution from the five RSU 1 communities – the funds raised through taxes – had been divided into two elements: a minimum amount that the state requires, and a portion over and above that amount. State subsidy to the district had been presented on a form based on the essential programs and services model.

The other local contribution piece was the additional amount each community must raise, beyond the EPS model. That contribution stipulated a cost-sharing formula based on equal thirds: student population, state valuation of a community and the community’s population in the most recent census.

The board had heard arguments from the public in support of the change, but its decision drew criticism from some municipal officials.

Alex Lear can be reached at 781-3661 ext. 113 or alear@theforecaster.net. Follow him on Twitter: @learics.