American Council of Engineering Companies

2004 Engineering Excellence Grand Award

CATEGORY E - SPECIAL PROJECTS

SUB-SURFACE DRAINAGE/CONSOLIDATION SYSTEM

POWNAL, VERMONT

PROJECT HIGHLIGHTS

Photo and award plaque

• Reclamation of superfund site for location of a new wastewater treatment facility.
• Unstable clay layer at depth would result in excessive settlement of 3"-5" over 5-10 years.
• Pile foundations would not be cost effective or practical due to soils.
• Wick drains purge moisture from unstable clay layer and accelerate consolidation of clay layer to acceptable consolidation.
• $70,000 installation project saved 3-5 years of consolidation from conventional pre-loading, which would have delayed the project to the point that the site would have been unacceptable.
• Close coordination with EPA to integrate this work into the phases of their overall lagoon clean-up.
• Cost of wick drain installation and pre-loading of site were including in EPA clean-up project funding, saving the town of Pownal $400,000 in project costs as well as substantial time.