This article was published on: 12/15/10 12:00 AM
Water treatment decision on tap
By Nick Grube / The Bulletin
Published: November 26. 2010 4:00AM PST
Bend city councilors are scheduled to decide Wednesday on what water treatment method they want to include as part of a proposed $73 million overhaul of its Bridge Creek infrastructure that supplies about half the municipality’s annual water supply.
The city, in order to comply with U.S. Environmental Protection Agency regulations, must begin treating its water by 2012 to account for micro-organisms, such as Cryptosporidium, which can cause human illness.
City officials and engineering consultants have suggested two treatment options for councilors to choose from. One is to use ultraviolet lights to basically alter the DNA structure of micro-organisms so they can no longer reproduce and make people sick.
The other is to use a membrane filtration system that in essence would act like a strainer, taking out the micro-organisms and other debris.
The city’s preferred option is to use the membrane system, which is more expensive, because it can filter out debris and still treat for harmful micro-organisms should a wildfire occur in the Bridge Creek watershed.
With the UV system, city officials have said a wildfire would make treatment impossible because the water would be too murky for the lights to penetrate and debris couldn’t be filtered out. This would result in shutting off the system.
Estimated costs for a membrane filtration treatment plant are around $30 million, while a UV system would run about $25 million.
In addition to choosing one of these treatment options, the city will replace about 10 miles of aging pipelines that bring water from Bridge Creek, which is west of Bend near Tumalo Falls, to a facility about two miles west of the city off Skyliners Road before it’s diverted into town. This new pipeline is estimated to cost about $28 million.
The city is also exploring the possibility of adding a $13 million hydropower plant to the system to generate energy from the water rushing downhill from Bridge Creek to Bend. It was initially estimated this could generate up to $1.7 million in revenue in the first year of operation, but that number has since been revised to $700,000.
City Manager Eric King said councilors likely won’t decide whether to include the hydropower plant as part of the overall project until sometime in January or February when a more detailed analysis of the project costs and rate impacts will be available.
Depending on what councilors decide Wednesday and in the future for the Bridge Creek overhaul, ratepayers could see their monthly bills increase between 37.5 and 45.5 percent over the next five years, according to the most recent city estimates.
Those increases would be added to water rate hikes over the past three years, including a 7.1 percent increase in July, that were approved to help the city set money aside for the project.
If You Go
What: Bend City Council meeting
When: 5 p.m. work session, 7 p.m regular meeting Wednesday
Where: Bend City Hall, 710 N.W. Wall St., Bend
Nick Grube can be reached at 541-633-2160 or at ngrube@bendbulletin.com.
Published Daily in Bend Oregon by Western Communications, Inc. © 2010
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