The Columbia Boulevard Wastewater Treatment Plant was constructed in 1950 as an industrial site to treat the city’s combined wastewater and storm water now serving 600,000 residents in Portland, Oregon. In recent times, this municipal works project has become increasingly public through efforts to highlight the importance of sustainable infrastructure. Over the past 16 years, engineering staff on site worked out of portable trailers that became unsuitable for occupation.
The new 11,490 square-foot Engineering Building and site development project was proposed to create replacement office space while also establishing a new public interface for the Plant. The program included office space for 36 engineers and construction management staff, a visitor reception space and public meeting spaces all to be developed within a sustainable landscape.
The new single-storey building was oriented along the path of the sun featuring seven folded cast-in-place concrete roof forms that channel storm water sustainably through the eco-roof. The storm water then drains along the berms into a visible storm water collection system leading back to the Columbia Slough.
As an intentional demonstration, the building and its immediate landscape employ signage and educational elements to celebrate the Columbia Slough ecosystem where the project is located as well as share information about the regional watershed. Inspired by the native landscape and its industrial past, the building is an elegant combination of landform, indigenous planting, formal geometry, and durable construction systems that support staff and the public interface.
The site development transformed and redefined the transportation traffic flow to create a newly formed pedestrian central green space used for educational tours of the plant and as a commons for the overall plant staff. This commons space replaced the original axial road leading into the plant improving vehicular circulation, plant security, parking organisation to create a shared central gathering space.
Juxtaposing the soft, vegetated southern edge, the building’s northern facade is a dynamic, serrated curtain wall that tracks the circular path of the commons. Exterior stainless steel solar shades and a system of clerestory windows create modulated day lighting in concert with a fully glazed operable north facade connecting the interior spaces with the central green space.
The mechanical system is a heat pump system that taps into the plant’s process water source for heating and cooling. While the building has a photovoltaic system it also benefits from an on- site co-generation plant for power.
Info and images © Skylab Architecture
