Template revised January 10, 2019.
COMMISSION
AGENDA MEMORANDUM
Item No.
8b
ACTION ITEM
Date of Meeting
September 26, 2023
DATE: September 15, 2023
TO: Stephen P. Metruck, Executive Director
FROM: Eileen Francisco, Director, Aviation Project Management
Sarah Cox, Director, Aviation Environment & Sustainability
SUBJECT: Industrial Wastewater Treatment Plant (IWTP) Enhancements – CIP# C801234
30% Design Funding
Amount of this request:
$11,500,000
Total estimated project cost:
$250,000,000 - $350,000,000
ACTION REQUESTED
Request Commission authorization for the Executive Director to (1) advertise and execute a
project specific contract for Architecture and Engineering (A&E) services, (2) develop a project
notebook document and progress the overall design to 30%, (3) utilize port crews for enabling
work related to the Industrial Wastewater Treatment Plant (IWTP) project at Seattle-Tacoma
International Airport. The amount being requested under this authorization is $11,500,000.
EXECUTIVE SUMMARY
This project will install a pre-treatment system and upgrade the existing systems at the IWTP to
ensure compliance with future King County Department of Natural Resources Industrial Waste
Discharge permit limits.
The airport’s IWTP manages and treats stormwater associated with industrial activities from
aircraft fueling and maintenance operations as well as wastewater from other airport related
operations such as aircraft deicing. Stormwater runoff with low Biochemical Oxygen Demand
(BOD) discharges to the Puget Sound under conditions of National Pollutant Discharge
Elimination Systems (NPDES) permit. Stormwater runoff with high BOD discharges to King County
South Treatment Plant for secondary treatment under King County Department of Natural
Resources Permit No. 7810-05. The primary source of high BOD is aircraft deicer runoff. Effective
in 2026, the King County BOD permit limits will be restricted to a level that will require an on-site
pre-treatment system at the Seattle–Tacoma International Airport (SEA).
The amount of this request is $11,500,000 to complete 30% Design and the Project Notebook.
The total estimated project cost is currently $250,000,000 - $350,000,000. Staff will return to the
Commission following the completion of 30% design work; at this time staff will provide an
COMMISSION AGENDA – Action Item No. 8b Page 2 of 6
Meeting Date: September 26, 2023
Template revised June 27, 2019 (Diversity in Contracting).
updated project cost estimate and request authorization for design funding to move forward
with the remaining detailed design phase.
JUSTIFICATION
Since 2007, the IWTP has discharged industrial wastewater runoff containing aircraft deicers to
the King County Wastewater Treatment System. Through each permit cycle, King County has
restricted discharges because under sustained heavy deicer loads, the performance of the
County’s treatment plant has been disrupted by the Port’s discharges.
Over the past five years, the Port has evaluated technologies and methods to reduce impacts to
the King County treatment plant. This evaluation included a comprehensive assessment of
deicing source control, storage, and treatment technologies. This assessment resulted in
measures to reduce the amount of aircraft deicer applied and implemented operational
efficiencies. For example, most of the aircraft deicer applicators switched to an application
technology reducing the amount of deicer applied. This source reduction reduces the amount of
future storage needed.
Under the terms of the July 2021 Industrial Waste Discharge (IWD) permit, the Port is required
to implement infrastructure and operational modifications by 2026 to comply with future
discharge limits. The previous BOD mass loading limit of 60,000 lb/day will be reduced to 15,000
lb/day maximum daily and 10,000 lb/day on a monthly average basis as of July 20, 2026, with
interim limits imposed in the current permit cycle. The IWTP modifications needed to comply
with these reduced limits include significant additions to the system for storage and
pretreatment of IWS stormwater containing spent aircraft deicing fluid. The 2021 IWD permit
also includes a compliance schedule over the next five years to reflect progress toward
implementation of measures to meet reduced 2026 effluent limitations. Given the complexity of
the scope, the current project schedule shows a completion date more than 2 years after the
IWD permit limits have taken effect. The Port has been in communication with King County
Department of Natural Resources regarding this schedule and has received an extension on the
60% and 100% design deliverables only. The Port will continue to collaborate to meet permit
limits during construction of the project.
While the Port has developed a preliminary design of the pretreatment and storage systems,
some elements of the design scope present risks to overall cost and schedule (phasing, controls
architecture, storage requirements, seasonal modeling, etc.). Development of a 30% Design
package will further develop these elements and provide an accurate cost estimate for long-term
decision making. The requested authorization will facilitate this process and keep the project on
the approved compliance schedule with King County.
Diversity in Contracting
There will be a 15% WMBE aspirational goal associated with this contract.
DETAILS
Requested funds will be used to develop:
COMMISSION AGENDA – Action Item No. 8b Page 3 of 6
Meeting Date: September 26, 2023
Template revised June 27, 2019 (Diversity in Contracting).
• 30% Design Package
• Project Notebook
• Updated cost estimate
• Further development of siting and permitting requirements
The 30% Design will develop scope of the pre-treatment system, water storage, and all associated
mechanical support systems. The pre-treatment system will need to be integrated into the
existing IWTP. The current plan is to procure and execute a project-specific contract for A&E
services.
Scope of Work
30% Design of the following systems will be included in the scope of the Project Notebook:
(1) Upgrades to existing IWTP systems (dissolved air flotation systems, pumps, controls,
etc.).
(2) Pre-treatment flow diversion and influent system
(3) Storage systems to facilitate pre-treatment.
(4) BOD treatment system (aerated gravel beds, oil-water separators, drainage, etc.).
(5) Effluent discharge systems.
(6) Pumps and systems.
(7) New support systems (controls building, power supply, controls, HVAC).
The Scope of Work will also include a preliminary phasing plan and cost estimate.
Schedule
The current project schedule shows an in-use date between Q4 2026 - Q2 2027. The dates shown
below are based on conservative assumptions in procurement, permitting, and construction.
Options to further compress the schedule will be evaluated during the planning phase to ensure
that discharge to the King County STP complies with anticipated 2026 BOD permit levels.
Activity
Design start
Commission full design authorization
Commission construction authorization
Construction start
In-use date
Cost Breakdown
This Request
Total Project
Design
$11,500,000
$28,000,000
Construction
$0
TBD in 30% Design
Total
$11,500,000
$250M - $350M
COMMISSION AGENDA – Action Item No. 8b Page 4 of 6
Meeting Date: September 26, 2023
Template revised June 27, 2019 (Diversity in Contracting).
ALTERNATIVES AND IMPLICATIONS CONSIDERED
Alternative 1 – Do not proceed with this project.
Cost Implications: Approximately $1,500,000 would need to be expensed. BOD levels would
exceed permit allowances and likely result in significant fines indefinitely. The Port would not be
in compliance with Wastewater Discharge Permit No. 7810-05.
Pros:
(1) No capital investment required at this time.
Cons:
(1) Failure to meet King County permit levels for the new permit cycle will leave limited
options for managing de-icing runoff at STIA. High BOD wastewater at the IWTP will not
be able to discharge to the King County South Treatment Plant.
(2) In order to comply with reduced limits, the IWTP current storage is not sufficient and
could result in overflow of untreated water into adjacent receiving waters.
(3) High risk of violating King County and NPDES permit requirements. Increased risk of King
County restricting or ceasing discharges during high-risk operational periods.
This is not the recommended alternative.
Alternative 2 – Develop 30% Design to determine approach for implementation of a pre-
treatment system at the Industrial Wastewater Treatment Plant (IWTP).
Cost Implications: $11,500,000
Pros:
(1) Implementation of a pre-treatment facility on-site at STIA will allow continued discharge
to the King County South Treatment Plant.
(2) King County Department of Natural Resources requires submittal of the Draft Design
Documents (60%) by September 30, 2025 and the Final Design Documents (100%) by
March 20, 2026. This approach will allow the Port to meet the current permit schedule.
Note that while King County has approved these project milestone dates via the Final
Engineering Report, management of BOD effluent limits after June 2026 will require
further collaboration between the Port and KCIW.
(3) The 30% Design will allow the long-term design team to develop an overall design
philosophy for the final system, reducing uncertainties which could have an impact on
project cost and schedule. Comprehensive existing conditions and permit requirements
will be evaluated, and an updated project cost estimate will be developed.
Cons:
(1) Capital investment of $11,500,000 is required to develop 30% Design (current total
project estimate is $250M - $350M).
This is the recommended alternative.
COMMISSION AGENDA – Action Item No. 8b Page 5 of 6
Meeting Date: September 26, 2023
Template revised June 27, 2019 (Diversity in Contracting).
FINANCIAL IMPLICATIONS
Following a third-party cost estimate, as part of the 30% Design, the project will update the
revised estimate for total project cost.
Cost Estimate/Authorization Summary
Capital
Expense
Total
COST ESTIMATE
Original estimate
$127,000,000
$0
$127,000,000
Transfer from IWTP Controls
$10,600,000
$0
$10,600,000
Current Budget Estimate
$137,600,000
$0
$137,600,000
Revised Estimate Range
TBD
$0
$250,000,000 -
$350,000,000
AUTHORIZATION
Previous authorizations
$2,135,000
$0
$2,135,000
Current request for authorization
$11,500,000
$0
$11,500,000
Total authorizations, including this request
$13,635,000
$0
$13,635,000
Remaining amount to be authorized
TBD
$0
TBD
Annual Budget Status and Source of Funds
This project, CIP C801234 was included in the 2023-2027 capital budget and plan of finance with
a budget of $127,000,000. The capital increase of $10,600,000 was transferred from the
Aeronautical Allowance
1
CIP C800753 resulting in no net change to the Airport capital budget.
Note that the initial cost of C801234 was set at $100,000,000 for a new pretreatment system;
this value was set before the system scale required to meet the King County permit limits was
understood. This was combined with $37,600,000 from projects C801123 and C801122, which
were intended to upgrade mechanical and controls systems at the existing IWTP. The current
budget of $137,600,000 does not account for the overall complexity of a project of this
magnitude.
The cost is estimated to be within a range of $250 - $350 million. This cost is based on estimates
developed from the preliminary design, and the wide range is a result of large uncertainty in the
capability of the existing storage capacity of the system to meet pretreatment requirements.
These uncertainties will be evaluated in the 30% Design to allow for final decision-making by
project stakeholders. The funding sources would include the Airport Development Fund and
revenue bonds. Most of the project costs would be recovered through airlines rates. The
Majority-In-Interest ballot would be submitted to the airlines for approval in late 2024, once the
30% Design and cost estimate has been developed.
1
The Aeronautical Allowance is included in the Capital Improvement Plan to ensure funding capacity for
unspecified projects, cost increases for existing projects, new initiatives, and unforeseen needs. This ensures funding
capacity for unanticipated spending within the dollar amount of the Allowance CIP.
COMMISSION AGENDA – Action Item No. 8b Page 6 of 6
Meeting Date: September 26, 2023
Template revised June 27, 2019 (Diversity in Contracting).
Financial Analysis and Summary
Project cost for analysis
$250,000,000 - $350,000,000
Business Unit (BU)
Industrial Waste System
Effect on business performance
(NOI after depreciation)
NOI after depreciation will increase due to inclusion of
capital (and operating) costs in airline rate base.
IRR/NPV (if relevant)
N/A
CPE Impact
$0.57 - $0.87 in 2029
Future Revenues and Expenses (Total cost of ownership)
Aviation Operations and Maintenance have reviewed the preliminary design of the system, and
meetings have been held with leadership from each group to discuss expected additional costs
of ownership. The preliminary design documentation includes a summary of expected additional
operators needed to support the system, as well as additional maintenance and spare part
requirements. A full evaluation of the future expenses will be provided with the completed
Project Notebook.
ADDITIONAL BACKGROUND
N/A
ATTACHMENTS TO THIS REQUEST
(1) Presentation
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS
December 14, 2021 (Item 8l) – The Commission authorized execution of a contract for
Architecture and Engineering (A&E) services to complete planning and preliminary design
for the Industrial Wastewater Treatment Plant (IWTP) Program (CIP C801234). The
amount of this request was $2,000,000.