On Wednesday, Sept. 6, the Resort Municipality of Whistler turns 20. The celebration is next weekend, at noon on Sept. 9, in the village. Cake will be served, there will be a display highlighting some of Whistler's history, and a reception at the museum. Expected to be on hand are Pat Carleton, Whistler's first mayor, Al and Nancy Raine, the Wallaces and many other people, both present and former residents, who have played a part in Whistler's history. The municipality has budgeted $10,000 for the birthday party. But Sept. 6 is the actual birthday. It was on that day in 1975 that the legislature proclaimed the Resort Municipality of Whistler Act. The events that led to that proclamation are complex, but one of the keys to the whole thing was the need for a proper sewer system to handle the growing population. Twenty years later, Whistler's sewage system is still expanding to meet the growth in the valley. Emergency improvements are underway to meet the existing loads on the plant. The first phase of a $21 million expansion of the plant is also being done, to meet the demands of the Whistler Valley when it reaches build-out. A study of the Cheakamus River is also being conducted to determine the source of phosphorus in the river.