2023 Volume 72 Issue 1 Pages 31-42
Water supply facilities that supply water to more than 100 residents or supply more than 20 m3 of water per day are called specified privately owned water supply systems (SPOWs). SPOWs and small water systems require proper maintenance and management at their facilities, especially small water systems including private drinking water wells, where many water quality incidents involving health hazards have occurred. Most water quality incidents in SPOWs occurred in facilities where the groundwater was used as raw water, requiring thorough water quality management by those who install SPOWs. In addition to recent water quality incidents associated with microbial contamination in drinking water storage tanks, the incident at a building of university hospital is introduced. In October 2021, methemoglobinemia developed in 10 of 17 infants in the neonatal intensive care unit of the university hospital. It was found that these infants had been fed milk that had been prepared in the kitchen within the building of university hospital. It was finally proved that the water was contaminated with nitrite contained in the anticorrosion agent used in the air-conditioning system due to cross-connection.
