Despite what could be a good water year, city officials are seeking ways to conserve water by recycling, reusing and reapplying wastewater effluent.
Officials with the cities of Ketchum and Sun Valley and the Sun Valley Water & Sewer District attended a joint meeting Feb. 16 in which they heard a status report of wastewater treatment upgrades and possibilities for reuse.
The shared Ketchum/Sun Valley Wastewater Treatment facility is undergoing a $7.4 million, three-phase improvement project, under the direction of Pharmer Engineering.
When complete, wastewater effluent will be considered Class A, the highest quality as determined by the Department of Environmental Quality classification, said Steve Hansen, utilities manager for the city of Ketchum.
That classification allows water to be reapplied as irrigation on some publicly used lands, such as golf courses and parks, and to be used for purposes like snowmaking.
"That will provide us with other options than just putting it into the (Big Wood River)," he said.
Treated wastewater flowing into the river is considered Class C, disinfected and very clean, but not rising to the higher standard required for application on land or groundwater recharge.
"Our goal is to use (treated wastewater) in solving needs around Sun Valley and Ketchum," Hansen said after the meeting. "And by using that water for irrigation, that will lessen the need to pump water from the ground."
Reapplication has the additional benefit of recharging the aquifer, Hansen said, and limiting warmer, treated wastewater from affecting river waters that are naturally colder.
Reuse will have a payback period of less than 20 years, according to Pharmer Engineering.
Phase 2 of the project is in hiatus for the winter, but work will continue in April on the aeration basin.
"The basin is built, all the concrete is poured," Hansen said. "We'll be tying things together and testing everything."
Phase 2 should be done by July.
The city will soon solicit bids for Phase 3, wherein contractors will install filters for an added step in the treatment process.
"It'll take treated effluent and run it through a cloth filter process and remove even minute particles to give us a very, very clean effluent," Hansen said.
Once the project is done, residents will help decide recycled wastewater applications.
"We'll have public meetings as to how best to use this water," Hansen said, "because people need to buy into this."
Once sites and reuse options are hammered out, the next step is soil studies, regulatory approval, permits and other environmental reviews.
The first phase of the three-year project was completed last spring.
During Phase 1, a UV system was installed to disinfect wastewater and major electrical upgrades were completed.
In February 2004, Ketchum and Sun Valley voters approved a bond measure to finance the project.
The plant—which is located south of Ketchum, near the intersection of state Highway 75 and Elkhorn Road—is owned jointly by the cities of Ketchum and Sun Valley.
Capital costs for major upgrades are split between the two cities. Operating costs are determined by the percentage of flows.
