Computer Flaw Makes Water Undrinkable

Event Year: 1998 Reliability: Likely But Unconfirmed
Country: United States
Industry Type: Water/Waste Water

A computer glitch shut down the chlorination system and caused the chlorine content of the city water to drop below the safety threshold, affecting 40,000 residents.


This occurred during the night and was not discovered until a routine check 14 hours later. Notices were then sent out to 9,000 homes advising people ‘to boil the water before drinking.’

Action Description: The city has now installed an automatic system to notify an on-call supervisor in case this recurs.