My DD has attended the camp ("juniors") for the last several summers. The staff are a mix of teachers, grad students, college students and some high school students. My impression is that the high school students are essentially junior / assistant counselors and not left in charge for extended periods.
The program is fairly well organized. Each session has a theme around which the activities are organized.
I've never worried about my DDs safety while there, and she has a lot of fun. She keeps wanting to go back and won't consider other day camps.
I'm sure if you contact the directors that they would be more than happy to answer your questions.