GORHAM – School officials have announced that construction of a new $21 million elementary school will soon get under way.

The new school, designed by PDT Architects of Portland, will house 550 students in kindergarten through Grade 5. The school, which will replace the White Rock School, is slated to open in September 2011.

A groundbreaking ceremony is set for 4:30 p.m. on Friday, Oct. 16, at the 26-acre site off Sebago Lake Road (Route 237). The new school site is a short distance north of the roundabout in Little Falls. The School Department has invited local and state officials including Susan Gendron, state commissioner of education, to the ceremony.

Last week, the Gorham School Committee authorized Superintendent Ted Sharp to sign an agreement with Davis & Hanscom Inc., of Steep Falls as the project’s general contractor to build the school, though Sharp said Tuesday afternoon the deal hadn’t been signed yet.

The School Department received 10 bids to build the school.

“They were the low bidder,” Dennis Libby, School Committee chairman, said Tuesday.

Jim Hager, School Committee member and chairman of the school’s building committee, said total cost of construction would likely fall between $15 million and $16 million.

But, exact final cost of construction of the building hasn’t been determined because negotiations with some sub-contractors are still under way, according to Hager.

Hager said the state had approved spending up to $25 million as a total cost of the school, including up to $19.6 million to cover construction costs. “We’re building this at the right time,” Hager said with an eye on the economy.

The total amount of the $21 million for the new school project includes approximately $2 million in fees and services along with about $3.9 in administrative costs, Hager said.

Davis & Hanscom also built the Gorham Middle School, which opened in 2003.