Anglian Water says it has precautions in place to ensure any terrorist attempts to tamper with supplies can be detected.
Anglian says precautions in place against terrorists
The attacks on the World Trade Centre and Pentagon in America have made people more aware of the lengths terrorists will go to.
Anglian Water has more than five million industrial, commercial and domestic customers across the east of England. But the water company says they should have 'no fears at all' about the risk of deliberate attempts to contaminate drinking water.
Spokesman Adrian Smith said: 'We've taken all suitable precautions, including making sure that sites are alarmed and tagged and we can tell if anyone has been tampering with them or any unauthorised entries.
'The water quality is measured throughout the process so if there was any sign of something untoward we would know and it would trigger our emergency procedures.
'People would be told not to drink it or to boil their water or whatever was required.
'Customers should have no fears at all,' he said.