Can UV light kill bacteria in water?
UV light kills bacteria, viruses, and some cysts. It does not kill Giardia lamblia cysts or Cryptosporidium parvum oocysts, which must be removed by filtration or distillation. UV is not recommended if the untreated water has a coliform content exceeding 1,000 total coliforms or 100 fecal coliforms per 100 milliliters. Jan 4, 2011