The treatment works was taken out of
Three schools were also closed on Friday.
A Bristol Water spokesman said staff had been taking samples from the treated water storage reservoir in Clevedon and at customers' houses.
He said: "No cryptosporidium has been detected in any of these samples.
"We have also fully flushed the water network in the area meaning the network now has a fresh supply from other sources.
"Consequently, following consultation and advice from Public Health England, we are now lifting the precautionary boil water notice."
Cryptosporidium can cause extreme diarrhoea called cryptosporidiosis.
