Building a larger water treatment plant at a new location makes more sense than expanding operations at the current site or building a smaller additional plant that could run in tandem with the current plant, according to a city staff report up for discussion at Monday night’s City Council study session.
A plan to build a supplemental 2.5 million gallon per day (mgd) plant and 2.6 million gallon reservoir was included in the city’s 2012 Water Master Plan. Funding to proceed with engineering for the plant and reservoir were approved by the council in March 2017, only to be put on hold by the council in November at the recommendation of new Public Works Director Paula Brown, partly because installation of a connection to the Talent Ashland Phoenix water line offers a reliable alternative water source.
A cost comparison study concludes a new 7.5 mgd plant could be built without changing the current budget allocation of $22.7 million that had been intended for the supplemental 2.5 mgd plant and reservoir. The study was compiled by RH2 Engineering in partnership with Black and Veatch at a cost less than $34,900, according to a city staff report. Paula Brown, who has been spearheading the effort to reevaluate the city’s water needs after TAP was implemented, will give a report Monday night at the council’s study session. The report lays out staff’s recommendation of the 7.5 MGD treatment plant.
According to staff report, the city’s existing water treatment plant is facing three major risks — seismic stability, flooding and capacity for future growth — it “could not fully overcome” and “is not acceptable.”
“In addition, deferring construction of a new plant only imposes greater overall cost to the city,” the staff report reads. “The existing plant has a finite life and the city’s needs continue beyond that life span.”
While a 7.5 mgd plant would cost quadruple the estimated $5.6 million it would take to rehabilitate the existing plant, “deferring construction of a new plant beyond the 20-year planning horizon will impose a greater overall cost to the city,” according to the engineers’ report. The report also says the current plant, wedged between a steep hillside and Ashland Creek approximately midway between Lithia Park and Reeder Reservoir, is vulnerable to flooding in the event of heavy rain or the collapse of Hosler Dam and landslides in the event of an earthquake.
The staff report also says that the city will see a potential increase in operational costs due to the new location of a plant, new pumping costs and additional personnel.
The cost comparison is conducted under the assumption that the new plant employs similar treatment technologies.
According to staff report, the new plant will increase quality by including new treatment that would address algae, avoid natural hazards of floods, earthquake and landslides by locating the facility at a lower elevation down the stream, and reduce redundancy by operating only one treatment plant. The 7.5 mgd plant capacity will also accommodate the city’s water needs for at least the following 20 years, the staff report says.
The city came up with a plan for a 2.5 mgd plant as the current facility’s utilities and infrastructure — electrical systems, control systems, mechanical equipment — “is near the end of its useful life.”
The council won’t be voting at Monday meeting — it will give staff direction on the project. If the new plant is approval, staff will come back to present a Request for Quotation with recommendations of a consultant next year.
—Reach reporter Tran Nguyen at 541-776-4485 or tnguyen@rosebudmedia.com. Follow her on twitter @nguyenntrann.