The cloudy water some Challis residents might have noticed recently was caused by turbulence that produced air bubbles during a switch over to the city’s West Well No. 1, Mayor Michael Barrett said.
The cloudy, naturally bubbly water was nothing like it was in the bad old days. Slow sand filter settling ponds were installed 75 years ago and the chlorination plant followed. Before that, residents drank muddy runoff out of Garden Creek, which had run through upstream ranches and cattle herds.
The slow sand filter ponds are still filled every spring and the water that flows through them is released back to Garden Creek, Barrett said. In the event of an emergency, such as a long power outage that shuts down the city’s well pumps, water from the ponds can be run through the chlorination plant and into the city’s drinking water system.
Challis usually pulls its water from a series of four wells, three on the golf course that tap into the Garden Creek aquifer and one that taps the Salmon River aquifer. None of the water from the pristine underground water sources has to be treated. A couple of weeks ago some residents noticed the milky-cloudy water and wondered what was in it.
It was air bubbles that formed in the water drawn from West Well No. 1, Barrett said. The turbulence occurs because the well doesn’t have separate inlet and outlet pipes as the other wells do. The inlet and outlet connecting it to the city’s concrete water reservoir above the golf course are the same, Barrett said, which means that currents of water flowing out of the well and out of the reservoir at the same time collide, creating turbulence and air bubbles.
West Well No. 2 was offline temporarily this spring while a flow meter was pulled out and shipped off for repair, Barrett said. That was why West Well No. 1 was the primary source.
Every week the city rotates water flow among the three wells for efficiency and to give each pump a chance to rest.