BATH — Next year’s Regional School Unit 1 budget goes to the first of two district-wide votes Tuesday, May 28.

The $27.7 million spending plan, unanimously approved by the RSU 1 Board of Directors on May 6, will increase 6.66 percent over the current year if approved both times.

With offsetting revenues subtracted, the amount to come from taxes would be $18.6 million, a 7.19 percent hike.

Through a new cost-sharing formula that assesses the RSU 1 communities on a per-pupil basis, Bath, West Bath and Woolwich could see significant school tax increases: 6.3 percent in Bath, to $9.1 million; 24.1 percent in West Bath, to $2.7 million, and 16.5 percent in Woolwich, to $3.6 million.

Arrowsic could benefit from a tax reduction of 2.6 percent, to about $481,000, and Phippsburg school taxes could decline 10.6 percent, to $2.7 million.

The School Board recently opted to add two items to next year’s budget that it had previously discussed: an assistant boys’ lacrosse coach for about $2,300, and about $15,000 to the system-wide staff development account.

As urged by several members of the public, the board has also added two teaching positions late last month without increasing the bottom line: a certified health teacher at the middle school level, and a new teaching position at Woolwich Central School.

The latter addresses concerns about the size of the current fifth-grade class at Woolwich Central School, which has one teacher for 28 students.

The May 28 district budget meeting will be held at Bath Middle School at 6 p.m. The spending plan then goes to a budget validation referendum on June 4 at polling places in the five RSU 1 communities.