Whistle Lake Plant
In 1950 the city system added four more filters to the Whistle Lake plant, bringing the city’s capacity to 11 mgd.
Ranney Collector Wells
To meet the added demand of the Tesoro and Shell oil refineries, the city built two Ranney Collector Wells (lateral pipes located under the Skagit River bed) placing them into service on July 15, 1955. The south well contained three 28,000 gpm pumps with 400 high-pressure motors, and the north had two 2,800 gpm pumps with 400 high-pressure motors. Problems with iron content later developed with these wells and by the fall of 1957 the city was constructing a plant to filter the water from the Ranney collector wells outside of Mount Vernon. At the time, it was believed to be the largest pressure filter plant in the world. On March 11, 1958, this new filter plant was put into service.