PLUM — A school district where three teachers are awaiting trial on charges they had sexual relationships with students adopted a policy that spells out limitations on student-teacher contact, including social media and other electronic ways of communication.

The Plum School Board voted 7-0 Tuesday night to approve the policy, which applies to employees, coaches, volunteers, student teachers and independent contractors who interact with students.

It states “students of any age are not legally capable of consenting to romantic or sexual interactions with adults.”

That’s an issue because one of the teachers charged with having a sexual relationship has argued it wasn’t illegal because the student was 18 by the time they had sex. Allegheny County prosecutors contend that teacher began “grooming” that student for the sexual relationship by kissing her and having other inappropriate conduct with her before she was an adult.

Whether that particular criminal charge stands the scrutiny of the criminal process, Plum officials wanted to spell out what’s appropriate — and what’s not — when teachers and other adult staff communicate with students.