Up to 40,000 residents on the NSW Central Coast were told to boil drinking water, after E. coli was previously detected in a reservoir, but new testing has cleared the supply of contamination.

An alert issued by Central Coast Council said samples from the drinking water supply contained E. coli bacteria.

Residents in some NSW Central Coast suburbs have been advised to boil their tap water due to the possible contamination of the local water supply with E. coli bacteria. A "boil water alert" was issued by Central Coast Council last night after recent samples detected the presence of E. coli bacteria.

Central Coast Council issued boil water alert E. coli found after testing of Terrigal Reservoir READ MORE: Sydney swim spots are contaminated with 'faecal matter' Up to 40,000 Aussies are being urged to boil their water after E.

Almost 50,000 residents on the Central Coast have been told not to consume tap water unless it has been boiled, after sampling revealed the water supply had " potentially been compromised".

Users of water supply in Terrigal, North Avoca, Avoca Beach, Copacabana, MacMasters Beach, Picketts Valley, Erina, Erina Heights and Kincumber are advised to boil water prior to consumption. Central Coast Council issued the alert after 6pm today, Tuesday, February 5.

People on the Central Coast have been instructed to boil tap water after testing detected E. coli bacteria in the local water supply.

A number of affluent southern Central Coast suburbs are being urged to boil water with recent investigations by council revealing the presence of a harmful bacteria at the Terrigal Reservoir.