Project Overview

Waterway Sediment Dredging & Removal

Site Overview

A busy waterway located within a Superfund Site contained legacy contamination in sediments, shoreline soils, docks, and pilings from over 100 years of industrial operations. Over 161,000 cubic yards of material required dredging or excavation to restore the river bottom and shoreline and improve salmon and other native wildlife habitat in the area.

Project Highlights

  • Mechanically dredged over 161,000 cubic yards of contaminated sediments using a barge-mounted excavator in a navigable, industrial waterway
  • Removed 75,000 cubic yards of shoreline soils using long stick excavators
  • Placed 300,000 tons of backfill sand from a flat deck barge in dredged areas of the waterway
  • Completed shoreline and habitat restoration to promote and protect wildlife and native vegetation
  • Treated and discharged 45 million gallons of water with no exceedance of water quality standards
  • Project received the World Organization of Dredging Associations (WODA) Environmental Excellence Award in 2016

Value Delivered

Envirocon maximized the effective work time ( EWT) of the dredge plant (actual dredging time) to reduce the schedule and costs through efficient project controls including comprehensive resource planning and adhering to a strict equipment maintenance schedule. Envirocon averaged a 70% EWT (typical average 50%) for the 2-year project.