SEATTLE -- Residents are encouraged to avoid contact with Lake Washington water near the site of a wastewater overflow that occurred Sunday afternoon.



An undetermined quantity of wastewater flowed into the lake for about 20 minutes near the South Mercer Pump Station. The pump station is located at the intersection of E. Mercer Way and SE 72nd Street on Mercer Island.



King County officials said the overflow from the pump station was caused by a mechanical problem during Sunday's power outage. The issue was fixed shortly after it was reported, and the station is now operating normally.



Officials said they will notify health and regulatory agencies of the spill, sample water quality and post signs warning people to avoid contact with the water over the next several days.