The incident occurred on 20 July, when the valve on a chlorine tank at the works was left closed after a routine changeover. It remained shut for 4.5 hours, stopping normal disinfection. In the evening of the same day, the company issued a precautionary warning to customers to boil their water.
The DWI is critical of the company for failing to take operational samples of water leaving the works and at most of its service reservoirs. Monit