Preston — A Hartford law firm has agreed to delay the $912,000 payment the town owes the firm for past work on failed proposed Norwich Hospital development deals until “vertical construction” begins on the Mohegan Gaming & Entertainment's planned $200 million to $600 million development there.

The proposed agreement with Shipman & Goodwin, an amendment to another amendment approved by voters in 2011, must be approved by voters at a town meeting. The Board of Selectmen set a town meeting for 7:30 p.m. Thursday, July 20, at Town Hall on the legal bill, a plan to purchase a handicapped-accessible school van, a proposed new blight ordinance and possibly another issue.

First Selectman Robert Congdon said when the town reached the agreement with the then-Mohegan Tribal Gaming Authority to sell the 388-acre former Norwich Hospital property, town officials asked Shipman & Goodwin to consider “softening” the amended agreement for the bill that covered legal costs for the failed Utopia Studios and Northland development plans.

The 2011 amendment called for the town to pay the bill upon sale of the property, or $5,700 per acre sold if the property was divided into smaller parcels. The new proposal would delay any payment until the Mohegans start to pay property taxes on actual construction — not just the land — at the property.

“It was a very favorable proposal,” Congdon said Thursday. “We knew there would be a question by residents during public hearing and town meeting (on the sale to the Mohegans), so we wanted an answer from Shipman & Goodwin on their expectations and any consideration of softening the agreement. They came back with this proposal.”

The law firm already has approved the agreement, Congdon said.

Town and School Finance Director John Spang told the Board of Selectmen on Thursday that it would cost $61,167 to purchase a second 20-passenger special education student transport van with wheelchair capacity. The van would replace costly contracted services. School officials hope to obtain the vehicle by September to save about $4,000 in contracted services not in the budget, school board member Sean Nugent said.

The Board of Education also asked for a town meeting to allow the seven nonunion school employees to join the Municipal Employees Retirement System available to nonunion town employees. Congdon said he has not yet received information from the town attorney on the process for the expansion of the retirement program, but that item might be added to the July 20 town meeting agenda.

c.bessette@theday.com