Authors: Michael T. Berger Environmental Scientist William R. Racine Assistant Project Engineer Mark A. Bergeon Associate STS Consultants, Ltd. Green Bay, WI 54311-8320 (920) 468-1978 (920) 468-3312 Fax Abstract This paper addresses the unique design and construction features used in covering approximately 14,800 m2 of low strength contaminated sediments. A site assessment indicated that the upper 3.7 m to 5.4 m of sediment contained 10% to 30% solids. Challenges for the project included solving access problems and preventing the cover and construction equipment from sinking. The solution was winter construction on the frozen site surface and development of a lightweight, bouyant cover system. STS developed a cover system incorporating high-strength geotextile, polystyrene sheets and yard mulch. The yard mulch was placed on top of the geotextile cover, providing beneficial reuse of material and alleviating storage problems for a local municipality. The geotextile and yard mulch cover was supported by polystyrene sheets to provide bouyancy in areas of extreme low solids. A gravel perimeter berm was incorporated into the cover system to provide anchoring of the geotextile and containment of the polystyrene. Approximate fertilizer and seed mixtures were applied to the site in the spring to promote cover vegetation. For a copy of the full article, call STS Consultants at (847) 279-2477.