im gonna reply so maybe more people will respond! I am not a fan of ranking in general because I think its pretty biased, nevertheless its a good starting place. I bet you already looked here but just in case you didn’t.
http://grad-schools.usnews.rankingsandreviews.com/best-graduate-schools/top-science-schools/lehigh-university-213543
(grad school ranking)
All rankings-
http://colleges.usnews.rankingsandreviews.com/best-colleges/lehigh-university-213543/overall-rankings