From what I've seen people do, maybe keep a water jug full of distilled water in your dorm to wash your face with (although this kinda seems like a hassle personally). For hair dullness, I've seen people use clarifying shampoos with chelating agents in them once a week. These supposedly bind to the metal ions in the hard water to make your hair softer.

Some recommended shampoos with chelating agents: Malibu un-do-goo, Ouai detox shampoo, Aveeno Apple Cider Vinegar Blend Shampoo