Recent Rains Impact Drinking Water Treatment but Not Quality
Heavy rain in the McKenzie Valley over the weekend gave EWEB's water quality team a close look at the potential impacts from the Holiday Farm Fire on source water. Although increased monitoring detected elevated turbidity and nutrient levels, the Hayden Bridge Water Filtration Plant was able to modify treatment processes to ensure safe, high quality drinking water to homes and businesses.
The Holiday Farm Fire burned 173,000 acres and more than 430 homes in the watershed that produces every drop of water flowing out of Eugene's taps. In the aftermath, we are working in partnership with local and state agencies, watershed researchers, forest management agencies and local non-profits to identify threats to our water supply and public health, prioritize watershed restoration activities and help with long-term community recovery.
EWEB is working with landowners and community partners to keep burned debris and toxic ash out of the river until it can be safely removed.
Partnering with Oregon State University and Pacific Northwest National Laboratory, EWEB recently placed additional water quality monitoring stations in the mainstem McKenzie River and several smaller creeks and tributaries. This enhanced monitoring provides key information on the impacts of the fire on water quality during major storm events. In addition, EWEB worked with the U.S. Geological Survey to expand the network of gaging stations that include water quality sensors as an early warning system to allow water treatment plant operators to prepare for and adjust treatment strategies prior to the river water entering the filtration plant.
During this weekend's heavy rainfall, monitors detected turbidity levels that were 12 times higher than typical for the McKenzie River—a result of sediment and other particles from the surrounding land washing into the river. Real-time water quality sensors also detected an increase in organic material coming from the burned and eroded landscape around and above the river.
Monitoring equipment at Simmonds Creek where it enters Blue River showed elevated turbidity, whch refers to cloudiness or haziness caused by suspended solids.
Fortunately, the turbidity and organic impacts experienced so far are well within EWEB's filtration plants capability and capacity to handle.
Over the weekend, our water treatment staff increased use of powdered active carbon (PAC) and rapid sand filtration systems to ensure safe, high quality water and to mitigate any potential taste and odor concerns.
At the Hayden Bridge Water Filtration Plant we use a three step process to turn water from the McKenzie River into safe drinking water.
We anticipate enhanced monitoring and treatment will continue for some time.
The Holiday Farm Fire damage to the watershed has the potential to degrade water quality, increase treatment costs, and reduce the production capacity of EWEB's Hayden Bridge treatment plant for years, a fact that is driving an intense, multi-agency effort to install erosion control measures and revegetate burned landscapes in the McKenzie watershed as quickly as possible.
Erosion control measures are being installed to keep sediment and other burned material from washing into the river.
"Protecting source water is protecting the community," said EWEB's Watershed Restoration Program Manager Karl Morgenstern. "On the heels of the Holiday Farm fire, there is a both a need and opportunity for community-wide mobilization to restore the watershed and continue to protect this valuable resource."
Learn more about Holiday Farm Fire Recovery and Watershed Restoration
