COMMISSION 
AGENDA MEMORANDUM                        Item No.          6d 
ACTION ITEM                            Date of Meeting     September 8, 2020 
DATE:     August 17, 2020 
TO:        Stephen P. Metruck, Executive Director 
FROM:    Tina Soike, Chief Engineering Director, Engineering Services 
Janice Zahn, Assistant Engineering Director, Construction Services 
SUBJECT:  South Satellite (SSAT) Infrastructure Upgrade (CIP #C800798) Change Order Over
$300,000 

Amount of this request:            $0 
Total estimated project cost:        $52,232,000 
ACTION REQUESTED 
Request Commission authorization for the Executive Director to execute a Change Order to
Contract MC-0319530  South Satellite Infrastructure Upgrade for repair, replacement and
modifications to the heating hot water circulating pumps at the South Satellite (SSAT), Seattle-
Tacoma International Airport for an estimated amount up to $600,000.00. 
EXECUTIVE SUMMARY 
This change order will replace the existing 50-year-old constant volume hot water circulating
pumps and piping system with a new variable volume hot water circulation system. The new
variable volume system will provide both the new and existing HVAC systems with the required
hot water at the required operating pressure for a fully functioning heating system for the South
Satellite.  Adequate contingency exists within the current project budget and therefore no
additional funding is required. 
JUSTIFICATION 
This project was authorized for construction by Commission on October 23, 2018. When
completed in the fourth quarter of 2021, the project will improve the effectiveness, reliability, 
and increase the capacity of the Heating, Ventilation, and Air Conditioning (HVAC) system for the
SSAT, a terminal that has seen dramatic passenger growth since its construction in 1970's and
expansion in 1982. The scope of the work includes replacement and upgrade of the existing
original air handler and HVAC system on the concourse level, ceiling, lights and associated
electrical equipment, fire sprinkler system, signage, portions of the terminal-wide voice paging
system, column cladding, and carpet. 

Template revised September 22, 2016.

COMMISSION AGENDA  Action Item                                        Page 2 of 4 
Meeting Date:
The new HVAC system, currently under construction, was designed with a variable hot water
recirculating system to provide greater energy efficiency for the Port.  The variable hot water
recirculating system is a critical component required to meet Washington State Energy Code.
While performing initial testing and balancing of the new HVAC system, it was discovered that
the operating pressure of the existing hot water circulating system was less than 2 psi compared
to the required operating pressure of 50 to 60 psi. Upon investigation, it was determined the
existing 50-year-old constant volume hot water circulating pumps and piping configuration is not
compatible with the variable volume flow requirements of the new system and will not provide
the required operating pressure to allow the HVAC system to operate as needed. Unfortunately,
the implications of providing water to a variable volume system from a constant volume system
were overlooked during design.
The additional HVAC capacity will also accommodate the expansion of the Airport Dining and
Retail (ADR) at the SSAT, providing needed customer amenities. Maintaining comfortable heating
and cooling is a necessity for a satisfying customer experience. While the Port is interested in
undertaking a major renovation of the SSAT within the next 10 to 15 years, the project currently
underway is addressing the inadequacy of the old HVAC system and its risk of failure. Currently 
the SSAT Concourse level is supported by a temporary HVAC system; the old HVAC system has
been demolished; and the new permanent HVAC system is being installed.
In addition to providing a more reliant HVAC system, upon completion it is anticipated the Port
will realize an increased heating and cooling energy efficiency of 15% to 20% on the SSAT
concourse level system. Calculations estimate electric savings of 163,300 kwh/year and natural
gas savings of 20,600 therms per year for a total energy savings of 21,168 therms/year and
reduced greenhouse gas emissions of 110 metric tons/year. (Approximately $20,000/year in
energy savings) 
When design on this project began in 2015 the Port undertook a very detailed review of the scope
of work to be performed in the SSAT. This revi ew focused on maintaining a minimal scope of
repairs and improvements to the SSAT to maintain building operations for a 10 to15 year period
while the Port planned for a major renovation of the SSAT. An outcome of the scope review was
a determination that the existing constant volume (CV) hot water circulating system could be
operated and maintained for the next 10 to 15 years. 
The project's design team has developed a design solution which will be implemented with this
change order.
.
FINANCIAL IMPLICATIONS 
There is no additional funding being requested in this memo.

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item                                        Page 3 of 4 
Meeting Date:
ALTERNATIVES AND IMPLICATIONS CONSIDERED 
Alternative 1  Perform work as separate Major Contract. $800,000 to $900,000 
Pros: 
(1)   None 
Cons: 
(1)   The cost of a separate Major Works contract would exceed cost of a Change Order.
Performing  this work as a separate major contract would result in additional
administrative costs to prepare and issue bid documents and manage the contract. For
projects of this size, the costs typically range from 33% to 50% of direct construction
costs ($200,000 to $300,000 additional). 
(2)   A separate major contract would result in delays to the current construction contract. 
Completion of the SSAT HVAC renovation project will not occur until the hot water
circulation system has been modified. The time required to procure and complete this
work under a separate contract is estimated to be 6-9 months. This delay would impact
the completion of the SSAT project by 4-6 months with the Port responsible for the
delay costs of approximately $100,000 per month. 
(3)   Complicates Warranty Management. Every Major Works contract comes with a one -
year warranty on the work. Doing this work as a separate contract would result in two
warranties from two different contractors on a single system. If there was a system
problem during this time, maintenance staff would be required to perform additional
investigation to determine which warranty applies.  Additionally, either contractor
could dispute the findings resulting in additional time and effort by the Port to
determine responsibility further delaying repairs. 
This is not the recommended alternative. 
Alternative 2  Approve the Change Order request 
Pros: 
(1) Adequate contingency exists within the current project budget. 
(2) Eliminates the 6-9-month procurement time and maintains the project schedule.
Planning to execute the work is underway. 
(3) Single point of contact for warranty issues. All work will have been performed under a
single contractor. The contractor will be the single point of contact for warranty issues. 
Cons: 
(1) None. 
This is the recommended alternative. 
ATTACHMENTS TO THIS REQUEST 
None. 

Template revised September 22, 2016; format updates October 19, 2016.

COMMISSION AGENDA  Action Item                                        Page 4 of 4 
Meeting Date:
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS 
April 8, 2019  Commission approved execution of Regulated Materials Management Monitoring
Specific Service agreement of $1,000,000 
June 26, 2018 -Commission approved the additional scope and authorized design at a cost of
$800,000 that was briefed on June 12, 2018. 
June 12, 2018 -Commission was briefed on irregular bid and adding scope to the project to reduce
risk to the Port and Contractor. 
November 28, 2017 -The Commission authorized $1,425,000 additional, for a total project cost
of $13,925,000. 
August 8, 2017 -The Commission authorized $11,200,000 for the advertisement, bid, and award
the construction contract for the South Satellite HVAC Upgrade project. November 8, 2016 - The
Commission authorized $3,450,000 for the preparation of design  and construction bid
documents, the advertising and execution of a major works construction contract, and the
utilization of Port crews for the South Satellite Structural Improvements (CIP C800818). 
July 24, 2012 - The Commission authorized $6,500,000 for the redesign the SSAT HVAC systems
to meet current and future requirements. The design included adding an additional penthouse
system, replacing three existing systems, reconfiguring the ductwork, and replacing all the
distribution boxes. The 2012 estimated costs of these improvements were about $37 million. The
design effort was suspended in 2013 and canceled in 2014 after staff determined that: 
(1)      The SSAT would require a seismic upgrade to facilitate any new systems. 
(2)      IAF and SAMP may change the use of SSAT. 
May 3, 2011 - The Commission authorized the negotiation and execution of a professional
services contract for design services. No funding was associated with this authorization. 
September 22, 2009 - The Commission was briefed on the condition of the HVAC systems of the
North and South Satellites. 





Template revised September 22, 2016; format updates October 19, 2016.