City switches water supply
Turbidity in Bull Run watershed causes reliance on groundwater wells.
On Saturday, the Portland Water Bureau switched from the Bull Run watershed to the Columbia South Shore Well Field as the source of the city's water.
The switch was made because recent heavy rains and increased stream flows have contributed to a rapid increase in turbidity - or suspended sediments - in the Bull Run system. The Bull Run water supply does not have a filter for reducing the contaminants. The well field draws on water in the aquifer along the Columbia River. It meets or surpasses all federal and state drinking water regulations.
"We are blessed to have two high quality sources of water available to us," bureau Administrator David Shaff said in a prepared statement. "When Mother Nature hits us hard, it's tremendously comforting to know that we can turn to our Columbia South Shore Well Field when the Bull Run system is shut down due to turbidity. It is extremely rare to have a backup system such as Portland's and it is one of the primary reasons we have been able to retain the Bull Run as an unfiltered source."
According to the bureau, it will take about 24 to 60 hours for groundwater to move through the distribution system, depending on a customer's location. Users will experience a switch from 100 percent Bull Run water to 100 percent during that time.
The bureau will operate the groundwater system as long as weather conditions and water quality require. Customers with questions can call the Water Line, 503-823-7525.