Geren Island Water Treatment Plant

    Geren Island, a small island just Southeast of Salem, Oregon, is home to the Geren Island Water Treatment Plant (GIWTF) that treats freshwater from the Santiam River. For more than 80 years, the GIWTF has been an efficient, reliable component of Salem’s potable water system. The slow sand filtration treatment process has effectively treated water from the North Santiam River; however, recent changes in the North Santiam Watershed have created significant challenges for the GIWTF. Improving the resiliency and treatment capability of the GIWTF was key to the project’s success.



    The new Ozone Treatment Facility kills the bacteria found in the Santiam River by pumping ozone through the water, then breaking down the ozone molecule, producing safe drinking water as a result. MWA designed the ozone facilities and plant modifications required to support the new treatment process, including the process pump station modifications. The new ozone treatment building connects directly to the concrete ozone destruct building, which captures and breaks down residual free ozone from the water stream.


    Due to the hazardous nature of the building, it is not functional as a typical workspace. Employees enter the building for a short period of time to ensure that the process is running smoothly. To simplify wayfinding for staff, MWA focused the design on the exterior, creating a clearly defined entrance and adding dimension.

    Working with the predetermined concrete and CMU, designers blended the natural colors of the two buildings. Metal accents create contrast and texture, complimenting the rust-orange color at the entrance. Metal framing around the windows adds shading and dimension, creating form to a wall that would otherwise lack interest.