Item No. 8b_supp
Meeting Date: October 26, 2021
Snow Storage Expansion Project (C801171)
Mike Tasker & Chris Coulter
AVPMG
C801171
October 26, 2021

Action Requested
Request Commission authorization to design and prepare
construction documents for the Snow Storage Expansion Project
(CIP 801171) at Seattle Tacoma International Airport. The total
request for this action will be $2,500,000 for a total project
authorization to date of $2,794,000. The estimated overall cost
of the project is $17,500,000.


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Project Overview
This is a regulatory project
Provide Additional Snow Storage Capacity Connected to
Industrial Waste System (IWS)
Existing capacity is inadequate
All snow melt areas must be connected to IWS for NPDES Permit Compliance
Historical excess snow storage areas now occupied by Cargo/RON aircraft
Increase operational safety for snow operations vehicles
Reduce operational expenses from rehandling snow
Snow storage capacity at completion of the project:
Target: single snowfall of 12 Inches plus 20% extra capacity for smaller storms
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Snow Storage Expansion Sites
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Scope Summary
Phase 1-2023 Construction
North Snow Storage Area
Expand existing asphalt pad and upgrade the IWS Pump Station
South Snow Storage Area*
Expand existing truck turnaround for maneuverability and safety
Vehicle Service Road (south and west of RW 34R)
Widen asphalt surface for snow removal vehicle safety
Phase 2-2024 Construction
Construct New Storage Area NE of Lagoon 3
Includes wetland mitigation

*SAMP TW A/B project will remove this snow storage area, decreasing overall capacity by 10,000 CY
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Construction Schedule
Phase 1
Commission Authorization for Construction Q4 2022
Issue Notice to Proceed: Q1 2023
In-Service: Q4 2023
Phase 2
Commission Authorization for Construction Q4 2023
Issue Notice to Proceed: Q1 2024
In-Service Q4 2024

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Budget
Snow Storage Expansion                         This Request                    Total Program
Project (C801171)

Design                                                  $2,500,000                           $2,794,000
Construction                                                       $0                           $14,706,000
Total                                                               $2,500,000                                $17,500,000




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Project Risks
RISK                DESCRIPTION                PROBLEM    IMPACT      MITIGATION PLAN
Permitting Delays        Wetland permit and mitigation     Med            Med           Separate design schedule for
implementation could delay                                      Phase 2 that allows for
construction of Phase 2                                            permitting and agency
negotiation period
Increased Cost           Wetland permit conditions and     Med            High           Increase project contingency
mitigation requirements will be                                     due to risk.
further refined during design
phase affecting potential cost of
mitigation

Unforeseen Site         Possible conditions include:        Med           Med           Implement monitoring and
Conditions                 Buried debris                                                  action plan for construction for
Archaeological                                                                     possible discoveries.
Unsuitable soil conditions


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Project Opportunities
Support other program scopes and schedules
Airfield Pavement and Supporting Infrastructure Replacement Program
Perimeter Intrusion detection System (PIDS)
Mid-field Checkpoints
Reduce operational impacts and safety risks by bundling



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