Supervisors/Department Chairs:

The College may be held strictly liable for sexual harassment by supervisors even if College administrators didn't know about the offending conduct and had no reason to know about it.
While the determination of whether someone is a "supervisor" is made on a case-by-case basis, the amount of control or influence that person was able to exert over the victim's employment will be important. Department Chairs would most likely be considered "supervisors" for this purpose.
If retaliation occurs, the college may further be held liable for those actions. Retaliation can be found in cases where a supervisor discouraged a student, colleague, or other person from filing a formal complaint.
In some circumstances, the College may avoid paying all or some monetary damages to the victim if there was a reasonable procedure in place to address the sexual harassment and the victim unreasonably failed to use that procedure. For example, if the College has an effective complaint procedure in place, and the victim does not use it, the victim may not be entitled to recover monetary damages for sexual harassment that could have been avoided if he or she had made a complaint.

Non-Supervisors:

The College may be held liable for an employee's sexual harassment of a fellow employee or student, or for a student's sexual harassment of another student or faculty member if, in either case, the victim can establish that College administrators either knew or should have known of the offending conduct but did not take immediate and appropriate corrective action.

If any "supervisor" knows about the offending conduct, the College will ordinarily be deemed to know about it. Again, Department Chairs would probably be considered "supervisors" for this purpose.
A prompt and effective response to sexual harassment complaints is important for two reasons. First, the College wants to preserve a working and learning environment that is free from sexual harassment. Second, a prompt and appropriate response can help the College avoid or limit potential legal liability.
For both these reasons, it is imperative that any and all complaints about conduct that could be considered sexual harassment - whether made by faculty, staff, or students - be taken seriously and promptly reported to an appropriate campus administrator.
"Magic words" are not required. If there's any question about whether particular conduct could be considered sexual harassment, and even if the complaintant doesn't call it "sexual harassment," it should be reported to an appropriate administrator so the College can take appropriate action.
Retaliation, whether by suggesting that there are negative consequences for reporting harassment, further harassment, or other discrimination is prohibited. Anyone engaging in retaliatory behavior is subject to the same discipline as someone who engaged in harassment.
In some circumstances, the College may avoid paying all or some monetary damages to the victim if there was a reasonable procedure in place to address the sexual harassment and the victim unreasonably failed to use that procedure. For example, if the College has an effective complaint procedure in place, and the victim does not use it, the victim may not be entitled to recover monetary damages for sexual harassment that could have been avoided had if he or she had made a complaint.