Hurricane Sandy: Tips to Make Tap Water Safe for Drinking If water supply becomes contaminated, you can either boil water for one minute or make water safe with bleach. Here is how: If tap water is clear: Add eight drops of household unscented liquid bleach to one gallon of water. Mix well and wait 30 minutes or more before drinking. If tap water is cloudy: Add 16 drops of unscented household liquid bleach to one gallon of water. In addition: Never mix bleach with ammonia or other cleaners. Open windows and doors to get fresh air when you use bleach. For more information, go to the Centers for Disease Control and Prevention website.