Environmental elements were analyzed by a team of technical analysts hired by the Port of Seattle. For each environmental element, the team evaluated the probable significant impacts associated with the proposed action, operation and cumulative impacts of the alternatives. 

Reasonable mitigation measures are identified in the FEIS that significantly mitigate these impacts. Mitigation refers to the ways to reduce the severity or seriousness of the impacts. Mitigation regarding air, noise, and transportation were areas of particular interest to the community based on comments submitted during the public scoping period and during the DEIS comment period. See below for a summary of the mitigation for the Preferred Alternative.

Air

PhasePotential ImpactsMitigation

Construction

  • Construction could cause short-term increases in local concentrations of dust and diesel-related air contaminants and possibly odors.
  • No significant air quality impacts are expected.
  • GHG emissions from construction activities were quantified during General Conformity review. GHG emissions were less than 10,000 tonnes/year. The Department of Ecology considers emissions under 25,000 tonnes/year not significant.
  • Construction activities would comply with local, state, and federal air quality regulations requiring minimization of construction-related emissions.
  • Implementation of BMPs to reduce potential for air quality impacts during construction identified in Chapter 3, Section 3.2.
  • Require contractors to prohibit Tier 0 and Tier 1 off-road equipment, to have on-road fleet meet 2007 EPA engine standards or better, and to enforce an idle reduction plan.

Operational

  • Model-predicted concentrations of criteria air pollutants, including shorepower capability, indicate that emissions do not exceed any National Ambient Air Quality standards (NAAQSs).
  • No significant impacts are expected with health-protective NAAQSs, air quality standards.
  • Facility operations would result in emission of GHG’s, but no impact thresholds have been established. Given the world-wide nature of climate change issues, and the relatively small contribution from this facility, the Project would not result in significant impacts from GHGs.
  • The Project would reduce world-wide emissions of GHGs due to improved efficiencies in commodity deliveries compared with existing transport systems – and due to improving emission controls in future years.
  • Measures intended to reduce operational emissions (including GHG Emissions) include:
    • Reduction of at-berth emissions from ocean-going vessels through the use of shorepower. The NWSA, the Port, and the terminal operator will prepare a shorepower utilization plan to meet projected shorepower utilizations levels.
    • Through the Northwest Ports Clean Air Strategy, the NWSA has adopted a plan to require trucks entering container terminals to meet model/year 2007 EPA emissions standards in 2018.
    • Development of facility will utilize an electrical power supplier that obtains >90% of their power from non-fossil fuel sources, reducing greenhouse gas emissions for terminal operations.
    • Operational management plans to reduce truck queuing and wait times, as outlined in proposed Queue Management Plan (FEIS, Volume II, Appendix C) will reduce idling of diesel drayage vehicles.
    • Port will analyze Terminal 5 air quality performance following resumption of container cargo operations to ensure air quality evaluations included in the EIS are consistent with operations. Data and analysis will be in consultation with PSCAA.
PhasePotential ImpactsMitigation

Construction

  • Pile driving may be intrusive and potentially annoying at times. However, pile driving sound levels are expected to fully comply with the noise limits applied by the City of Seattle to these types of activities.
  • Typical construction activities would be limited to between 7 AM and 10 PM weekdays and between 9 AM and 10 PM weekends and legal holidays.
  • Impact pile driving would be limited to between 8 AM and 5 PM weekdays and between 9 AM and 5 PM weekends and holidays.
  • Noise from all on-site construction activities would be subject to noise limits established by the City of Seattle.
  • The Port will develop a construction noise management plan prior to start of construction in consultation with the Seattle Department of Construction & Inspections (DCI).

Operational

  • Noise analyses and evaluation calculations indicate potential nighttime noise exceedances from cargo handling equipment and truck operations for future, more intense cargo activity.
  • Pure tone safety alarms on mobile cargo handling equipment, although not regulated, are an annoyance noise.
  • Train horn noise required for public and private crossings and presence of human activity, although not regulated, are an annoyance noise.
  • On-vessel power generators are perceived as annoyance noise.
  • Establish an Operational Noise Management Plan/Program. Use of a noise management program would provide objective noise monitoring data and a mechanism to identify reasonable and feasible best practices to ensure compliance with applicable noise limits. The noise management program would include measurement, reporting, and compliance steps to meet applicable Seattle City noise limits. This program would be developed in consultation with the Seattle Department of Construction & Inspectionsli>DCI). (See Volume II, Appendix M, Operational Noise Management Plan.) Annoyance Control Measures:  
  • Ensure that all mobile cargo handling equipment uses ambient-sensing, broadband safety alarms.
  • Addition of safety measures to the rail corridor between the bridge across the Duwamish and the terminal. Adding safety measures to the rail use area, including perimeter fencing and installation of crossing gates would reduce the need for locomotive horns. These measures could also be used by the City of Seattle as a basis to begin the process of requesting this section of rail lines be converted into a railroad quiet zone.
  • Reduction in noise from on-vessel power generators due to the provision of shorepower for moored vessels.

PhasePotential ImpactsMitigation

Construction

  • Construction activities would generate truck and employee trips, but less than No Action Alternative.
  • Potential detours required during construction.
  • BMPs for traffic control and safety during construction and adherence to SDOT permits and requirements. Coordination with other construction projects.
  • Prepare a Haul Route Plan and Traffic Control Plan for work in City right-of-way.
  • Coordinate with other construction projects in site vicinity.

Operational

  • Trains could increase from 9 to 18 trains in the peak week.
  • Increased closure time at near-terminal grade crossing due to increased train volumes and switching movements.
  • Expected additional utilization of storage tracks in the West Seattle Yard (WSY) to support the increased rail volume.
  • Alternative 2 is projected to result in 1,080 additional Design Day truck trips. It would have the highest peak hour truck trips and is estimated to generate an additional 130 truck trips during the AM peak hour and 31 truck trips during the PM peak hour on the Design Day.
  • Highest traffic impact on Lower Spokane Street and East Marginal Way between S Hanford Street and Duwamish Avenue S, which are the primary routes between Terminal 5 and near-dock intermodal yards.
  • The Project would increase vehicle delay at key intersections along SW Spokane Street.
  • Gate queuing could increase.
  • Pedestrian access to terminal could be affected by increased train blockages at West Marginal Way.
  • At full operation, north leg of the intersection at SW Spokane Street/West Marginal Way SW/Chelan Avenue SW closed. All traffic to and from Terminal 5, as well as local industrial businesses located north and east of the rail lines north of West Marginal Way Southwest, should be directed to use the Terminal 5 Access Bridge. Interim measures could convert surface access to entrance only and install advance notification signs.
  • When surface access is closed, provide alternative pedestrian access to terminal.
  • Comprehensive signal improvement along SW Spokane Street from Harbor Avenue SW to E Marginal Way S, and include the signal at E Marginal Way S/S Hanford Street. This project should include upgrading the signal controller at the five-legged intersection and improving interconnection equipment, if needed.
  • Implement Gate Queue Management Plan.
  • Implement additional driver information systems include advance signage about rail blockages and add Terminal 5 to the NWSA’s Wait Time Awareness System.
  • Improve access for industrial business located north and east of rail lines serving Terminal 5 and West Seattle Rail Yard by providing additional lane on Terminal 5 Access Bridge (if feasible), adding signage and striping along existing surface routes, and other measures.
  • Continue to work with SDOT related to off terminal truck parking.