If you leave it for several weeks to go on vacation without enlisting someone to drop by and water it or forget to water it yourself for long enough, your plant will start to suffer from dehydration.
Since your snake plant keeps good water reserves on its own, it doesn’t need to absorb too much from the soil. That means the soil will stay wet if you keep watering your plant.
Your tap water could contain chemicals like chlorine to kill pathogens and make it safe to drink. However, your snake plant may be more sensitive to chlorine than you are.