A LEAKING oil tank was found to be the source of pollution in a river near Llanberis.
Officers from Natural Resources Wales have identified a leaking heating oil tank from a nearby premises, which leaked into the foul sewer and entered the sewage treatment works, to be the source of reported pollution to Afon y Bala near Llanberis.
D?r Cymru Welsh Water announced yesterday (Thursday, June 12), that a turpentine-like substance had entered their sewage treatment works through the surface water system and entered into the river, which flows into Llyn Padarn.
A Natrural Resources Wales spokesman said: "After discovering the pollution, D?r Cymru Welsh Water acted immediately to contain as much of the oil as possible within the sewage network to prevent further pollution entering the river.
"The discharge has now stopped, but officers will continue to monitor the situation in the affected areas until water quality returns back to normal."
In the meantime, Gwynedd Council has placed signs on the bank of Afon y Bala near Llyn Padarn advising people not to swim in the area, and people may continue to notice some discolouration of the water over the weekend.
The spokesman added: "The council advised that warning signs have not been placed on the shore of Llyn Padarn, and watersports activity and swimming in Llyn Padarn is not restricted.
"Once the investigation into the cause of the leak is over, Natural Resources Wales will consider if it is appropriate to take any further action against the premises where the pollution originated from."