FARMINGTON — It’s official: The opening of all seven schools in the Mt. Blue Regional School District will be delayed until Sept. 6, according to an announcement made by Superintendent Michael Cormier late Thursday afternoon.

School had been scheduled to start on Aug. 31 for students in pre-kindergarten to grade nine and Sept. 1 for grades 10 to 12. Now, classes will begin on Tuesday, Sept. 6 for students pre-kindergarten to nine, and Wednesday, Sept. 7 for students in grades 10 to 12.

Three student days will be added to the end of the school year. School is now scheduled to get out on June 13 with no snow days.

Cormier made the decision because work on the new Mt. Blue High School and the Foster Career and Education Center is behind schedule and the grounds are currently an active construction site.

The problems include ongoing demolition of parts of the old school, 77 geothermal wells that must be drilled and continuing renovation and new construction at the Foster Center, Cormier told the school board this week.

The extra time would also allow contractors to complete a list of unfinished contract items at the new W.G. Mallett School. And it would give staff there more time to set up their rooms.

Cormier mentioned the carpeting for the library, for example, was still en route, so none of the books could be shelved.

At Tuesday’s school board meeting, directors had authorized Cormier to make the decision by Friday to delay opening day if he felt the high school was not ready for students.

“This gives me great peace of mind. I drove by (the school) and did not feel it was going to safe for the students,” Director Betsy Hyde of Temple said Tuesday.

In an email sent to staff on Thursday, Cormier announced the following schedule adjustments:

The staff workshop set for Monday, Aug. 29, will be moved to Mt. Blue Middle School.

Tuesday will remain the regularly scheduled staff workshop day.

If there is extreme weather due to Hurricane Irene, Monday’s workshop will be moved to Tuesday and Tuesday’s workshop moved to Wednesday. The change would be announced on the district website, www.mtbluersd.org.

It is anticipated teachers in the new wing at the Foster Center and in the 21 portable classrooms at the high school will be able to get into their classrooms by early next week.

“Furniture is arriving daily and is being set up. It will still not be completely finished, but I believe it will be very usable by Sept. 6,” Cormier wrote.