SYLVAN SLOUGH NATURAL AREA
The Sylvan Slough Natural Area is a private/public partnership to convert a contaminated 3-parcel brownfield industrial area to a public park at the edge of the Mississippi River. This important project for the Rock Island community acts as a 7.5 acre open space that initiates a public and private reinvestment in largely neglected area of the city. A cornerstone of this project is meshing US EPA mandated site remediation strategies with open space improvements in a manner that is cost effective, functional and aesthetically unique.
The site’s development over the last 100 years included everything from an ice house, which stored ice harvested from the adjacent Mississippi River slough, to a former oil-fueling station, a bulk petroleum storage facility, and a warehouse facility. Clean-up of soil contamination and toxic building materials were a major cost obstacle for future re-use of the property. The project design proposed a key strategy whereby the buildings would be carefully deconstructed, materials re-used on site, soil remediated and large industrial floors and foundations would remain intact. Initial work included careful inventory of existing building character and structural conditions to determine the deconstruction and park layout. Simultaneously soils were assessed and a bioremediation process was initiated. The bioremediation process involved mixing the contaminated soil with local manure from farms and woodchips from public facilities, to create “biopiles”. Once the soil was cured by UV radiation and micro-organisms, the soil was tested clean and re-utilized as landform fill throughout the site.
The park is also a demonstration for sustainable construction practices. For example, as the buildings were surgically deconstructed, materials were sorted for either on-site re-use or for off-site recycling. Materials that were toxic but non-mobile were entombed in the ice cooler basement and capped. Demolition and hauling costs were greatly reduced by retaining selected portions of existing site structures. Due to the uncoventional nature of the deconstruction, the design was tweaked as materials were uncovered or hidden walls revealed. What was originally thought to be solid concrete floor was actually large precast concrete panels. The panels were removed intact and re-used as risers and walkways through gardens. Where placement of traditional soil was infeasible, crushed clay tiles and compost were mixed to provide a planting medium for a sedum garden. Further, foundations, walls and pavements were selectively retained and reconditioned to articulate a network of walkways and rooms, with directed views to the slough, an eagle-viewing platform, or a small amphitheater. Building demolition materials were re-used as pedestrian paving materials and demolished concrete and brick block were crushed on site and either used as fill, permeable parking lot sub-base, or as a path surfacing material.
In addition to being the first significant public improvement in the transformation of a once prosperous industrial riverfront, the project now serves as a demonstration project for sustainable design and construction practices - all within the urban core of the Quad Cities. The project educates the public about the benefits of best management practices and the rich industrial heritage of the area with on-site interpretive programming. Upon completion, the project received several Illinois EPA awards and has been a case study at regional and national brownfield conferences.
City of Rock Island; River Action
Conservation Design Forum, Project designer and project manager from design through construction.
complete fall 2006