The Elliott Bay Seawall construction project spanned eight acres at Seattle’s waterfront. The original seawall had protected the city for decades, but exposure to the marine environment caused structural damage—cracks allowed saltwater to penetrate and deteriorate the timber piles supporting the wall.

Due to known contamination in the site's groundwater and soil, the seawall replacement project was regulated under the Department of Ecology’s National Pollutant Discharge Elimination System (NPDES) permit, with an additional Administrative Order imposing stricter controls to safeguard the waters of Elliott Bay.

A key challenge was managing two distinct dewatering systems under varying flow conditions while coordinating with complex and overlapping construction activities. Clear Water successfully mobilized and maintained dual treatment systems—one discharging to the sanitary sewer and one to surface waters. Throughout the project, Clear Water treated and discharged millions of gallons of clean effluent to Elliott Bay, maintaining full compliance with all environmental regulations.