Ecolab Manufacturing Engineering Co-op interview questions

Applied on-line and received notification that a representative was coming to my college (Penn State) and wanted to meet with me. Passed the initial interview and was then invited for a campus interview and tour. At the campus, we were introduced first to our 4 interviewers. Then is was back to back interviews with 1 on 1 with all 4 people for 1 hour each, totaling 4 hours.