Letter – New water filtration system good for Walla Walla’s future
I‘d like to point out a silver lining in the June 22 Union-Bulletin story about the $20 million filtering system the city of Walla Walla will be building at our water plant.
#About 15 years ago I was a member of the city Water Committee when it discussed how to deal with the cryptosporidium cysts found occasionally in our area’s untreated water. We considered two alternatives: ozone and filtration.
#A few committee members advocated for filtration because of its ability not only to catch the crypto but also to reduce sediment levels in the water. Our final recommendation, though, was to construct the less-expensive ozone plant. Ozone was then thought to be completely effective in disabling crypto, which was the specific problem before us.
#Since then, experience has revealed that ozone doesn’t work well when water is too cold, as it often is during winter months. Also, no disinfection system, including ozone, works well when water is full of sediment.
#In addition to assuring that those of us on city water won’t have to endure, or even pronounce, cryptosporidiosis, our new plant will also remove sediments so we can make use of water that would otherwise be too turbid because of wind, storms and floods, or rain following fires in the watershed.
#As climate continues to change, we face greater uncertainties in our water supply. We’ll likely see less snowpack, more large storms, more droughts and more wildfires.
#Because of its ability to remove part of the sediment in the water, our new filtration system should allow us to use more of the surface water we do have, and that will leave us and our children better prepared to handle some of the many changes ahead.
#Barbara Clark
# Walla Walla City Council member