Recomp Case Study

Temporary Ash Storage Facility

In 1989, Wilder Construction installed a modified asphalt concrete liner and cap at the RECOMP of Washington municipal incinerator in Whatcom County, WA. In this application, the system was used as both a liner and a cap. The modified asphalt was placed over an existing cell of the incinerator ash. A temporary incinerator ash cell was then constructed on top of the cap. Loaders, dozers and excavators have since operated directly on the cap, loading and unloading the temporary cell.

The original cap material was sampled in May of 1998 after nine years of use to test for physical degradation. No cracks were found in the modified asphalt. Core samples were tested for permeability and found to be identical with the core samples taken immediately after the original paving operation.

The modified asphalt concept proved highly successful and has drawn praise from the Washington State Department of Ecology and the operator of the site.

Aerial view of the incinerator ash cell showing re-exposed portion of the cap/liner after nine years of use.