Water-Main Replacement Big Challenge for Utility
Dameon Pesanti | The Columbian
Clark Public Utilities had a problem. It needed to replace a water main that connected wells in Salmon Creek Regional Park to a pipeline network to the north, but to get there it had to traverse Salmon Creek and a steep bluff to the north.
“So six years later, it’s still going on. Hopefully will be done in year seven,” said water engineering manager Russ Knutson. “It’s been the hardest job I’ve done in 25 years.”
Hard not because of the technical work involved but because of the permitting work associated with it.
It started in 2012 when a water main broke near Salmon Creek on the south side of the park. The broken line spilled some 11 million gallons of water before workers could find it — a challenge considering the line ran alongside the creek.
In 2013, the utility thought it could drill horizontally beneath the creek, run the pipe through the gap and then dig a trench up the slope, but that wouldn’t work. The slope material has evidence of an ancient landslide, its loose, rocky soil, choked with clays, mud and sand not conducive to the project. Project leaders then considered ramping a pipe into the ground and then drilling it out, but costs quickly ballooned…(Read the full story)