Swim warning after Llyn Padarn river pollution spill
A pollution spill has led to a warning people should not swim in the river feeding Llyn Padarn in Snowdonia.
Welsh Water said a strong smelling chemical had entered its sewage treatment works at Llanberis in surface water.
Natural Resources Wales (NRW) said a leaking heating oil tank from a nearby premises was the source and Welsh Water had contained the spill.
Warning signs have been placed on the Afon y Bala.
However, Natural Resources Wales said no restrictions have been imposed on the lake itself, which is a popular watersports destination.
A spokesperson for NRW said: "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."
Llyn Padarn is one of the deepest natural lakes in Wales, and home to a rare population of Arctic Char fish, which is a member of the salmon family.