Design Explorations of Phytoremediation and Legibility: Case Study of a University Landfill

Laura Davis

Chair of the Supervisory Committee:
Associate Professor Kristina Hill,Landscape Architecture Department

2004

The neglect of contaminated urban places often reflects ambiguity about the present and future ramifications of the contamination. Some of this ambiguity results from a lack of understanding. A university campus brownfield presents an opportunity to develop an aesthetic of phytoremediation that could increase understanding of invisible ecological relationships, human impacts and the importance of partnership in ecological repair.

The study site is the Union Bay Natural Area (UBNA), a 55-acre portion of the former Montlake landfill. Now classified as a Superfund site, the City of Seattle operated this landfill from 1926 to 1966 to help turn a marshy lacustrine wetland owned by the University of Washington into usable land. It lies adjacent to Lake Washington on one of the state's deepest peat deposits, has an incomplete cap of glacial till and no lining. Four issues guide my remediation strategy: 1) University students, faculty and staff have begun restoration efforts on the study site; 2) seasonal wetlands are a magnet for a diverse bird population and birding community; 3) management practices require avoiding landfill disturbance and minimizing human exposure to toxic accumulations; and 4) the lake is advancing into the landfill, due to subsidence.

On this site, phytoremediation can actively remove, degrade and stabilize soil and groundwater contaminants, lessening the risk of their translocation to wetland habitat. This economical plant-based technology promotes multiple functions of wildlife habitat, restoration of plant communities and soils, human recreation and access to nature, in keeping with the goals of UBNA.

By examining local campus planting patterns and historic practices of plant cultivation and harvest, I have identified culturally meaningful planting forms that can be used to build a new aesthetic of applied ecological process that might be readable through multi-sensory participation. With this design thesis, I propose an integrative approach that goes beyond both passive approaches to site remediation and aggressive removal of contamination. Through visible, participatory forms, I seek to shape and reveal ecological processes to create a responsive partnership between nature and culture. Such an approach could restructure our perception of time and the environment and create a new understanding of change.