PORT OF SEATTLE
MEMORANDUM
COMMISSION AGENDA
Item No.
6b
Date of Meeting
October 27, 2009
DATE: September 25, 2009
TO: Tay Yoshitani, Chief Executive Officer
FROM: George England, Program Leader, Aviation Project Management Group
Elizabeth Leavitt, Manager, Aviation Environmental Programs
Richard Ottele, General Manager, Aviation Facilities and Infrastructure
SUBJECT: Perform design and construction of new stormwater quality improvements at
Northeast and Southeast portions of airfield to meet national permit requirements.
Amount of This Request: $0 Source of Funds: Previously Authorized
ACTION REQUESTED:
Request Port Commission authorization, using previously authorized funds under the
Comprehensive Stormwater Management Program (CSMP), to:
1) Prepare final designs and construction contract documents; negotiate and execute a
service directive under an existing professional services agreement for final
engineering and construction management support; and
2) For Central Procurement Office to advertise for construction bids;
for the Stormwater Adaptive Management work in the SDE4/SDS1, SDN1, and SDS4
stormwater sub-basins for an estimated total project cost of $1,500,000.
SYNOPSIS:
The Comprehensive Stormwater Management Program (CSMP) was initiated in June 2002 in
response to permit conditions associated with the Airport’s Master Plan Update. Numerous
stormwater facilities were designed and constructed to meet regulatory requirements and are
currently operational. The stormwater program has now moved into its Adaptive Management
phase under which additional or upgraded stormwater facilities will be implemented, as needed,
to meet new regulatory conditions or to resolve other stormwater problems not previously
anticipated. Earlier commission authorizations anticipated this work. As a result, no budget is
necessary for this work. The proposed work, which is part of the CSMP Adaptive Management
phase, involves capital upgrades to existing stormwater quality treatment facilities and
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 2 of 7
construction of additional facilities in the SDE4/SDS1, SDN1, and SDS4 drainage sub-basins
(see attachment 1 for locations). The work is intended to provide increased treatment capability
to meet the effluent limits set forth in the new (effective April 2009) Stormwater National
Pollutant Discharge Eliminations System (NPDES) Permit that regulates stormwater outfalls at
the Airport. This work will reduce the risk of non-compliance with the permit conditions.
Implementation will be as a major public works project.
PROJECT DESCRIPTION AND JUSTIFICATION:
Stormwater flow control and water quality treatment facilities best management practices
(BMPs) were implemented during 2005 through 2007 under the CSMP and are now operational.
The Stormwater Engineering Report submitted to the Department of Ecology guided the
implementation of BMPs to meet the effluent limitations prescribed in the NPDES permit in
effect at that time. The BMPs were based on an All Known Available and Reasonable methods
of Treatment (AKART) report approved by Ecology. The original design and construction of
each CSMP facility incorporated an approach focused on minimizing initial capital costs with the
understanding that future upgrades may be needed to meet the conditions of a renewed, but more
stringent, NPDES permit. In 2006, the Adaptive Management phase of the CSMP was authorized
to provide for increased treatment capability, if needed. The renewed NPDES permit became
effective in April 2009, the permit lowered copper, and zinc effluent limits as summarized in the
following table:
Water quality monitoring of the sub-basin outfalls conducted over the last several years provides
data on the effectiveness of pollutant removal. The monitoring data has revealed several
instances where copper and zinc concentrations exceeded the limits set forth in the renewed
permit. Except for one exceedance that occurred in August 2009, approximately twelve other
exceedances did not cause permit non-compliance conditions since they occurred when the
previous permit was in effect.
Copper*
Zinc*
Receiving Water
Associated
Outfall
Previous
Permit
Previous
Permit
East Branch Des Moines
Creek
SDE4/SDS1
63.6
117
West Des Moines Creek and
Northwest Ponds
SDS4
63.6
117
Lake Reba
(*micrograms per liter)
SDN1
63.6
117
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 3 of 7
In response, under the Adaptive Management phase of the CSMP, selected stormwater sub-
basins were evaluated to determine what additional BMP improvements could be made to reduce
the risk of exceeding effluent limits in the renewed permit. The proposed work is an outcome of
that evaluation.
Several previous Port Commission actions authorized the entire CSMP. The Adaptive
Management phase was identified as an element of the CSMP scope of work in an April 11,
2006 Commission action. Funding for this project request is included within that 2006
authorization.
Project Statement:
Design and construct stormwater capital improvements to the SDE4/SDS1, SDN1, and SDS4
drainage sub-basins, including new facilities and upgrades to existing facilities, to increase water
quality treatment capability by December 2010 for a total project budget of $1,500,000.
Project Objectives:
Increase treatment capability in three stormwater sub-basins to reduce the risk of exceeding
effluent limits set forth in the renewed NPDES permit and being in a permit non-compliance
condition.
PROJECT SCOPE OF WORK AND SCHEDULE:
Scope of Work:
SDE4/SDS1 Sub-Basin: Modify two existing bio-swales to improve bio-infiltration and
treatment capability. Modify an existing vault to enable separation of the SDE4 and SDS1 flows
into separate bio-swales.
SDN1 Sub-Basin: Install a new pond drainpipe, using either a siphon or gravity flow pipe with
pump backup capability and an infiltration system to enable modified pond operation in batch
mode during summer low flow conditions, or install a new energy dissipation structure on the
pond inflow pipe to reduce re-suspension of settled material captured in the pond.
SDS4 Sub-Basin: Install a new bio-filtration and media contact channel downstream of the
existing flow control pond to provide water quality treatment.
Schedule:
Design completion: February 2010
Bid and award completion: May 2010
Construction and commissioning completion: September 2010
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 4 of 7
STRATEGIC OBJECTIVES:
This project supports the following Port-wide strategies to exhibit Environmental Stewardship
through our Actions to become the cleanest, greenest, and most energy efficient Port in the
world.
The project also supports the Airport’s Environmental strategies:
Improve Water Quality: Implement stormwater best management practices to improve
stormwater runoff quality.
Meet Environmental Obligations: The Port is obligated as a steward within the
community to comply with all environmental regulations. In addition, the conditions
within the 401 Certification and other permits are mandatory and must be complied with
as part of the implementation of the Master Plan Update.
Monitor for Long-term Compliance (2002-2017): As a direct requirement of the 401
Certification and other permits, the Port is obligated to monitor stormwater quality and
quantity and ensure protection of local creeks.
FINANCIAL ANALYSIS:
Capital Budget/Authorization Summary:
This project utilizes existing surplus and previous authorized stormwater budget for adaptive
management work. No additional budget is requested. The following capital budget and
authorization summary is for CIP 102030, Comprehensive Stormwater Management Program:
Original Budget
$76,749,495
Budget Transfers
$(17,134)
Revised Budget
$76,732,361
Budget Reductions
($18,276,573)
Current Budget
$58,455,788
CIP 102030 includes $12,400,000 identified for potential projects in the
Adaptive Management phase; approximately $454,000 has been expended
to date for other Adaptive Management efforts.
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 5 of 7
Previous Authorizations
$78,853,027
Authorization Transferred with Budget Transfers
$(2,120,666)
Net Previous Authorizations
$76,732,361
Current Request for Authorization
$0
Total Authorizations
$76,732,361
Estimate of Remaining Budget to be Authorized
$0
Project Cost Breakdown:
Construction plus sales tax
$1,138,000
Design
$156,000
Other
$206,000
Total
$1,500,000
Source of Funds:
The project is included in the 2009 – 2013 capital budget and plan of finance under CIP 102030.
The funding source will be Airport Development Fund 03040.
Financial Analysis:
CIP Category
Compliance
Project Type
Environmental
Risk adjusted discount rate
Not Applicable
Key risk factors
Not Applicable
Project cost for analysis
$1,500,000
Business Unit (BU)
Stormwater costs are allocated 86% to
Airfield cost center and 14% to Landside
Effect on business performance
NOI after depreciation for this project will be
positive due to recovery of 86% of the
operating and capital costs in the airfield cost
center through landing fees
IRR/NPV
Not Applicable
CPE Impact
CPE will increase by less than $0.01 in 2011.
However, no change to business plan forecast
as this project was included.
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 6 of 7
SUSTAINABILITY AND LIFE CYCLE COSTS:
Stormwater quality treatment facilities require on-going maintenance to perform at the design
intent and work towards meeting regulatory conditions over the long run. The proposed
treatment bio-swale at the SDS4 site and the drainpipe, infiltration system, and energy dissipater
at the SDN1 site will be new facilities requiring a slight increase in the overall stormwater
maintenance level of effort at a cost of approximately $2,000 per year, which will be addressed
in the 2011 and subsequent annual Maintenance Department budgets. The proposed work at the
SDE4/SDS1 site involves upgrades to existing facilities and is therefore not expected to change
the current level of maintenance effort.
ALTERNATIVES CONSIDERED AND THEIR IMPLICATIONS:
Alternative 1 – Implement the facility upgrades and additions as proposed. This alternative will
substantially increase treatment capability and reduce the chance of exceeding effluent standards
that would result in permit non-compliance. This is the recommended alternative.
Alternative 2 – Reduce the scope of the proposed work by eliminating one or more of the facility
upgrades or additions. This will reduce the project budget, but will not provide the increased
treatment capability believed to be necessary to significantly reduce the risk of exceeding
effluent limits. This alternative is not recommended.
Alternative 3 – Do not implement any of the proposed improvements. The facilities would
remain in their existing condition, exceedances of effluent limits would likely occur in the future,
and an increased probability of permit non-compliance situations would result. The Department
of Ecology could impose penalties for permit non-compliance. This alternative is not
recommended.
TRIPLE BOTTOM LINE:
The CSMP is driven by Port environmental stewardship, environmental regulatory requirements,
and the mandatory conditions of the 401 Certification for the Master Plan Update and NPDES
402 Permit. The program provides a cost-effective means of accomplishing necessary
environmental regulatory requirements. Facilities completed under this program provide an
overall benefit to the drainage basins, the community, and the region by enhancing stormwater
flow control and water quality that enhances fish habitat and improves the ability for further
development within the Airport and the adjacent communities.
PREVIOUS COMMISSION ACTIONS OR BRIEFINGS:
Previous Commission funding actions on CIP 102030 Comprehensive Stormwater Management
Plan include:
COMMISSION AGENDA
T. Yoshitani, Chief Executive Officer
September 25, 2009
Page 7 of 7
On June 11, 2002, the Commission authorized $1,000,000 to conduct preliminary studies
and finalize program definition and planning for a new Comprehensive Stormwater
Management Program, CIP 102030.
On March 11, 2003, the Commission authorized $9,354,000, which included an
additional $4,125,000 for continuation of CIP 102030 Comprehensive Stormwater
Management Program Plan and Definition; $3,731,000 for initiating CIP 102108 Drives
Connection to IWS Project; $668,000 for initiating CIP 102109 Stormwater Pollution
Prevention Project; and $830,000 for initiating CIP 102146 Low Flow Pilot Program.
On February 10, 2004, the Commission authorized $10,000,000 for continuation of CIP
102030, Comprehensive Stormwater Management Program Plan and Definition.
On May 5, 2005, the Commission authorized $14,981,000 for continuation of CIP
102030, Comprehensive Stormwater Management Program Plan and Definition.
On October 25, 2005, the Commission authorized $12,408,000 for continuation of CIP
102030, Comprehensive Stormwater Management Program Plan and Definition.
On April 11, 2006, the Commission authorized an additional cost of $36,208,000 for
continuation of CIP 102030, Comprehensive Stormwater Management Program Plan and
Definition. Funding for Adaptive Management phase stormwater projects was authorized
by this action.
On March 31, 2009, the Commission authorized final design and construction of capital
upgrades to the North Snowmelt and North Cargo stormwater pump stations under the
Adaptive Management phase of the CSMP.