Medford, OR's wastewater treatment plant, the Regional Water Reclamation Facility (RWRF), serves 170,000 customers in southern Oregon's Rogue watershed. Data shows the population increasing to over 204,600 in 2020. Although the RWRF discharges treated effluent, as population grows and requirements get tighter, it has the potential to exceed its temperature or thermal limits, especially during low-flow periods in the fall. To keep this from happening, RWRF plant engineers studied several solutions, including installing mechanical chillers and storing treated wastewater in an expanded pit. If the city had decided to upgrade the wastewater treatment facility, the cost would have totaled about $16 million.
Instead, the city signed a $6.5 million contract with the Freshwater Trust, a not-for-profit river restoration organization. Medford chose water-quality trading to solve the projected exceedance of thermal load and the Trust was hired to implement and maintain the ongoing 20-year project. The Rogue River draws native coldwater fish, including Chinook salmon and steelhead trout. They are listed as "threatened" under the Federal Endangered Species Act and, the two species are adversely affected by warm water. The Rogue River is also used for recreation, with participants taking jet boat tours, whitewater rafting, and kayaking.
The water-quality trading program adapted by the Trust features riparian restoration -- that is, planting and maintaining trees and shrubs along the banks of the Rogue and its tributaries. This streamside vegetation on 10 -- 15 miles of the river will cool the water temperature by blocking solar load in this ongoing project, according to the plan.