Foss Maritime Stormwater Improvements

Client: Foss Maritime
Strategy, treatment design, and agency negotiations to transition site discharge from sanitary sewer to surface water for an 11-acre active shipyard on the Lake Washington Ship Canal in Seattle, Washington. Floyd|Snider also supports continued NPDES compliance.

Overview of Floyd|Snider Contributions

Design lead for environmental, civil, electrical, and geotechnical engineering for stormwater improvements
Stormwater management optimization
Successful agency negotiations
Site planning for active shipyard operations
Permit compliance

Project Summary

Foss Maritime operates an 11-acre shipyard offering full-service vessel repair, maintenance, and new construction at their facility along the Lake Washington Ship Canal in Seattle, Washington.

Facility operations require coverage under a NPDES Individual Stormwater Permit for discharge of dry dock flood water and a Discharge Authorization with King County for discharge of industrial stormwater to the sanitary sewer. Due to capacity constraints of the King County sanitary sewer, the facility is required to cease discharge to the sanitary sewer and treat stormwater for discharge to the Ship Canal. Foss Maritime is embarking on a strategy to implement interim flow reduction measures with the ultimate goal of installing robust treatment for stormwater discharge to the Ship Canal. Foss Maritime expects to complete flow reduction measures by 2022 and will then focus on implementation of full-scale treatment and discharge to the Ship Canal.

Foss Maritime operates an 11-acre shipyard offering full-service vessel repair, maintenance, and new construction at their facility along the Lake Washington Ship Canal in Seattle, Washington. Facility operations require coverage under a NPDES Individual Stormwater Permit for discharge of dry dock flood water and a Discharge Authorization with King County for discharge of industrial stormwater to the sanitary sewer. Due to capacity constraints of the King County sanitary sewer, the facility is required to cease discharge to the sanitary sewer and treat stormwater for discharge to the Ship Canal. Foss Maritime is embarking on a strategy to implement interim flow reduction measures with the ultimate goal of installing robust treatment for stormwater discharge to the Ship Canal. Foss Maritime expects to complete flow reduction measures by 2022 and will then focus on implementation of full-scale treatment and discharge to the Ship Canal.

Our Approach

Floyd|Snider provides strong site planning and project leadership to Foss Maritime through engagement with King County and Ecology for regulatory compliance and stormwater management.

Floyd|Snider leads the project team from agency negotiations through concept development for stormwater management, design, permitting, contractor selection, and construction oversight. Floyd|Snider worked with King County to establish interim stormwater control measures and an implementation timeline that works within Foss Maritime’s capital budget forecasts and shipyard operations. Through coordination with project team members, Floyd|Snider has led efforts to design and construct an additional 150,000 gallons of detention to reduce flow rates into the King County sanitary sewer and ultimately reduce the size of the treatment system necessary for discharge to surface waters in the future. In addition to long-term facility planning, Floyd|Snider supports Foss Maritime for continued compliance with the facility’s NPDES permit and discharge authorization.

Project Milestones:

2019–2022. Interim detention measures
2024–2027. Stormwater treatment implementation

Floyd|Snider provides strong site planning and project leadership to Foss Maritime through engagement with King County and Ecology for regulatory compliance and stormwater management. Floyd|Snider leads the project team from agency negotiations through concept development for stormwater management, design, permitting, contractor selection, and construction oversight. Floyd|Snider worked with King County to establish interim stormwater control measures and an implementation timeline that works within Foss Maritime’s capital budget forecasts and shipyard operations. Through coordination with project team members, Floyd|Snider has led efforts to design and construct an additional 150,000 gallons of detention to reduce flow rates into the King County sanitary sewer and ultimately reduce the size of the treatment system necessary for discharge to surface waters in the future. In addition to long-term facility planning, Floyd|Snider supports Foss Maritime for continued compliance with the facility’s NPDES permit and discharge authorization.

Project Milestones:

2019–2022. Interim detention measures
2024–2027. Stormwater treatment implementation

Project Team

Floyd|Snider
KPFF Consulting Engineers
Elcon Associates
Haley and Aldrich (Formerly Hart Crowser)