Cryptosporidium is a pathogen that may cause a short-term respiratory and/or gastrointestinal illness. Although highly resistant to chlorine treatment, direct filtration techniques are sufficient for cryptosporidium removal. Giardia is another pathogen that may result in a variety of unpleasant stomach and/or intestinal illnesses. Direct filtration techniques of a water treatment plant are effective in Giardia's removal as well. In the case of an outbreak of either pathogen, boil water advisories are issued and effectively eliminate their threat to human health. This intitial 2-year testing schedule was required as part of the Long Term 2 Enhanced Surface Water Treatment Rule (LT2), which became part of the Safe Drinking Water Act in 2007.