HONOLULU (KHON2) -- The U.S. Army Garrison Hawaii has been alerted by the State Department of Health about a violation of drinking water standards due to the presence of E. coli bacteria. Get Hawaii's latest morning news delivered to your inbox, sign up for News 2 You On Dec. 16, a routine water sample from the Tripler Army Medical Center (TAMC) tested positive for total coliform bacteria. This led to additional tests to confirm the presence of E. coli. However, water remained safe to drink from Dec. 16-18 because it was disinfected, and no E. coli was found in the distribution system. The situation escalated on Dec. 19, when a sample taken from TAMC’s Water Well #2 tested positive for E. coli. The results were confirmed on Dec. 20, after an 18-hour processing period. The contaminated sample was taken before the water treatment process at the well, but subsequent tests of water within the distribution system showed no E. coli. In response, Water Well #2 was shut down on Dec. 20. It has since been disinfected, and further samples are being analyzed. The well will remain offline until testing confirms it is free of E. coli. In the meantime, Water Well #1 is providing safe drinking water. The Army, in partnership with the Hawaii Department of Health, is investigating the cause of the contamination. E. coli bacteria are often associated with human or animal waste and can lead to symptoms like diarrhea, cramps, and nausea. Vulnerable populations, such as young children, the elderly, and those with weakened immune systems, are at higher risk. Download the free KHON2 app for iOS or Android to stay informed on the latest news Residents are urged to discard any ice, beverages, formula, or uncooked food made with tap water from before Dec. 19. Officials are also asking residents to share this information with others who might drink the water, especially those in apartments, nursing homes, schools, or businesses. For more details, residents can visit the Army's drinking water page or call (520) 687-2207.