A water filtration plant at Salmon Creek would allow the secondary water source to be used all year and could potentially increase its capacity, Engineering Director Rorie Watt told the City and Borough of Juneau Assembly Committee of the Whole Monday evening.
Juneau receives the majority of its drinking water from the Gold Creek water supply in Last Chance Basin, but the possibility of mining development near the basin, as well as interest in a redundant water source for the city and an Environmental Protection Agency regulation that will require a secondary disinfection system for Salmon Creek, has spurred discussion over the Salmon Creek supply.
Initial conversations about how to meet the federal regulation focused on using ultraviolet radiation to treat the water from Salmon Creek for parasites and viruses, according to Watt. He said a UV radiation system would cost approximately $1 million.
However, Watt added, staff have more recently been considering a water filtration plant that could both disinfect the water and curb turbidity, cloudiness of the water that can occur seasonally and has caused the Salmon Creek water supply to be taken offline several times since 2005, according to a draft Municipal Drinking Water Supply Plan dated June 12, to which Watt referred several times during the work session.
“Filtration allows us to use Salmon Creek, or would allow us to use Salmon Creek, during periods of turbidity and use it year-round,” Watt said.
Watt estimated project costs for a filtration plant at Salmon Creek would fall between $3.5 million and $6 million, depending on the size and capacity of the plant.
A larger plant would effectively double Salmon Creek’s output capacity — when it is being tapped, the Salmon Creek source typically provides between one million and two million gallons of water per day, Watt said after the work session — and would be able to accommodate future growth. But Watt told the committee that it would not be used to its full capacity of four million gallons of water per day in the “short to medium run.”
“It would be a quite a while before we would use that much water from Salmon Creek, barring any number of things happening,” said Watt. “I think that if we look at a filtration plant at the nearer term, we would probably look at phasing it and building maybe a plant half that size, and anticipating a larger plant in the future.”
Watt said staff recommends making Salmon Creek a year-round supply while simultaneously keeping Gold Creek online, as well as working to “protect” the latter supply in case of mining activity around Last Chance Basin.
If the Gold Creek supply were taken offline, water distribution system upgrades to establish Salmon Creek as a reliable primary source for all of Juneau would cost between $1 million and $2.3 million, according to a Nov. 30 memorandum Watt discussed with the committee. Those costs are based off an assessment by Carson Dorn Inc., the technical memorandum from which is also dated to last Friday.
On a motion by Assemblymember Johan Dybdahl, the Committee of the Whole forwarded a draft resolution supporting the Municipal Drinking Water Supply Plan recommendations to the full Assembly for public hearing.
After Assemblymember Karen Crane said she wants to ensure public testimony will be heard on the resolution, Mayor Merrill Sanford said he would work with staff to keep it off the consent agenda, which is typically adopted without discussion.
Assemblymember Jesse Kiehl, who questioned Watt during the committee work session, said afterward that he is concerned that the Salmon Creek water supply project costs will go beyond the cost of a filtration plant alone.
“I think we need to be able to use Salmon Creek year-round and have the increased capacity,” said Kiehl. “But I don’t believe in blank checks.”
The committee very briefly discussed Assembly goals for the coming year. Setting those goals and Assembly priorities has been an ongoing process since the Assembly’s retreat in late October.
“The mayor and the manager have sent us the top action items, responsibilities, timeframe and status as a result of our discussion on the retreat and our last meeting,” Deputy Mayor Mary Becker, chairwoman of the Committee of the Whole, told her fellow Assemblymembers.
A list provided at the committee work session identified the Assembly’s “overall goals” as being to “preserve and improve local quality of life,” “improve infrastructure and services to and within our community,” “promote a healthy, growing economy,” “improve Juneau as a regional center and as Alaska’s Capital,” and “enhance the effectiveness of Juneau’s local government.”
Those goals included a number of “implementing actions.” Numbering among them are several “top action items,” including hosting a meeting with builders, lenders and property owners on housing development; developing the municipal water supply; completing a feasibility study on the A-J mine; and electrifying Veterans’ Memorial Highway to the end of the road, among others.
Mayor Merrill Sanford encouraged Assemblymembers to review the list and advise him of any changes they recommend. He said he will be working with staff as well on the details of the list.
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