An estimated 5000 litres of sewage leaked into George Town’s York Creek on Friday, according to TasWater.
A blocked pipe was the cause of the spill, which saw York Cove beach closed down for 24 hours after the incident.
TasWater worked with the George Town Council to disinfect and clean the area of all potential contaminants.
As of Sunday morning the beach was re-opened, meaning the planned Launceston Triathlon Club event will proceed as planned.
TasWater said a foreign item was identified as the cause of the blockage and was dislodged using a high-pressure hose.
The identity of the item in question is unknown.
“This is disappointing and inconvenient to those in the area on Friday and Saturday, but at least our initial findings show the spill was not the result of a TasWater infrastructure failure,” TasWater general manager of service delivery Bennie Smith said.
“Given the dry weather conditions, we were keen to understand what had caused the spill.”