^^There are some schools that lean more toward alcohol, others more toward weed, although at most, both are available to those who are interested and want company while partaking. I would say (being a parent so not getting this info first-hand) that of the NESCAC schools, Tufts and Wes are at the weedier end of that spectrum.
And yes, those 3 (and Hamilton, Bates, Midd, and Trinity) have plenty of drinking.
Of course, a student can have a great experience partaking of no substances. But it’s important to understand in the process what others will be doing and if it bothers you. Again, one of the benefits of Wes size is that there will be more people to do things with whatever you choose.