Narberth River is being polluted by raw sewage because the drains in the town are too small and are unable to cope with demand.
Speaking at Tuesday night's meeting of the town council, Deputy Mayor, Clr. Henry Langen, said he was receiving an 'incredible' number of complaints about the problems which were being caused because sewage was starting to back-up and flow out into the storm drain which discharged into the river near Narberth Bridge.
"It is a total health risk, big time," he stated.
Members agreed to contact the public protection division at Pembrokeshire County Council about the problem as a matter of urgency and send copies of the letter to Welsh Water and the Environment Agency.