Use of Ash as a Construction Material in the Vertical Expansion of an Existing Sludge Pond, 1995 Environmental Conference Proceedings

Richard M. Holland Environmental Packaging Corporation of America

R. Kent Nilsson

RMT, Inc.

Ray Chewning

Tensar Environmental Systems, Inc.

Jody Saiia

BEC/allwaste

Packaging Corporation of America (PCA) required additional capacity in an existing sludge basin. Expansion of the basin was necessary to meet both short-term and long-term needs. The basin was to provide adequate capacity and drainage to handle short-term dredge discharge from a primary settling basin. The sludge impoundment was to meet long-term desires to better utilize the impoundment. With this, future solid waste or dredge discharge could be placed in a way that would establish a stable subgrade suitable for ultimate closure. The expansion design included interior dikes constructed on the sludge surface using structural geogrid for reinforcement and wood ash as a fill material. The design also included an overflow structure and a drainage system that were constructed on the interior face of the ash dike to provide discharge of dredged liquids and storm water. A test section of the expansion system was constructed on the soft, compressible sludge surface. It was observed that with use of geogrid subgrade reinforcement, the ash could be placed, compacted, and shaped using conventional construction equipment. Full scale construction and in-service use found that the ash materials provided suitable dike stability.