Sewage was discharged into Joss Bay yesterday (February 16) due to a fault at the Broadstairs pumping station.
The wastewater was released at around 9.50am.Southern Water is now assessing whether neighbouring beaches have been affected by the pollution.
A clean up is now underway.
A Southern Water spokesperson said: “We’re very sorry to report that due to a fault at the Broadstairs Wastewater Pumping Station at approximately 9:50am yesterday wastewater was released via the emergency outfall into the area around Joss Bay.
“This was the only action available to us to prevent internal flooding to local properties.
“A full investigation is taking place to assess if other beaches nearby have been affected and we will provide an update as soon as we can. A beach walk and clean up is under way.
“No pollution is acceptable to us or our customers. We are working with the Environment Agency and Local Authority to assess the negative impact on the environment.”
Joss Bay has previously been affected by sewage releases in 2012 and 2014. The discharge in 2014 followed very heavy rain and affected Walpole, Palm Bay, Botany Bay, Kingsgate Bay, Joss Bay, Stone Bay, and Viking Bay.
A Thanet council spokesperson said precautionary advice is being issued to beach users at Joss Bay, Kingsgate Bay, Botany Bay, Stone Bay, and Walpole Bay not to enter the water below the high tide mark.
They added: “This follows notification from Southern Water that there had been a fault at Broadstairs Pumping Station.
Temporary signs are on display at the affected beaches. This advice is expected to be in place until tomorrow when Southern Water has completed a full clean up operation.
“Southern Water is also carrying out a full investigation and the council is working closely with them and the Environment Agency to understand the impact of this incident.”
County Councillor Karen Constantine is calling for upgrades at the pumping station.
She said: “I’m extremely concerned to hear about this sewage discharge, future events such as this need to be avoided. I’m calling on Southern Water to upgrade maintenance and to implement additional contingency plans to avoid a repeat of this incident.
“Our local marine ecology is precious. Greater care needs to be taken with our unique coastline. Thanet’s chalk cliffs are very special on a global scale, they support very specialised rare algae of high marine conservation value. That’s why we have SSSI status and other marine designations, it is vital that we protect them.