Water treatment facilities add chlorine as an antimicrobial agent. Chlorine deters the growth and presence of bio-contaminants like bacteria, viruses, and mold. Failure for municipalities to regulate sufficient amounts of chlorine in water mains can lead to waterborne illnesses and bacterial contamination. Flint faced a similar issue where levels of fecal coliform bacteria were discovered in city water. Adding more chlorine, however, is not the be-all-end-all. Chlorination of water can elevate levels of total trihalomethanes (TTHM), by-products of chlorination known to cause cancer. In a 2008 study, scientists determined that the presence of chlorinated disinfection by-products in drinking water was an issue of public health, posing health risks such as cancer in males and adverse developmental effect on infants.