Volume i executive summary

City of Oak Harbor

WASTEWATER FACILITIES PLAN
Executive Summary
DRAFT

March 2013

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ASSOCIATED FIRMS

This Wastewater Facilities Plan was developed in coordination with:

CAROLLO ENGINEERS DRAFT – March 2013

City of Oak Harbor

Wastewater Facilities Plan

TABLE OF CONTENTS

Page No.
ES.1 INTRODUCTION ....................................................................................................... 1
ES.1.1 Project Need ............................................................................................ 1
ES.1.2 Project Goal ............................................................................................. 1
ES.2 PLANNING AREA CHARACTERISTICS .................................................................. 2
ES.2.1 Service Area ............................................................................................ 2
ES.3 EXISTING FACILITIES.............................................................................................. 2
ES.3.1 Existing Treatment Facilities .................................................................... 2
ES.3.2 Existing Effluent Outfalls .......................................................................... 4
ES.3.3 Existing Wastewater Collection System .................................................. 4
ES.4 WASTEWATER FLOWS AND LOADS ..................................................................... 5
ES.4.1 Flow and Load Projections ...................................................................... 5
ES.4.2 Phasing Scenarios For Growth ................................................................ 7
ES.5 REGULATORY REQUIREMENTS ............................................................................ 8
ES.5.1 Effluent Quality Goals .............................................................................. 8
ES.5.2 Biosolids Management .......................................................................... 10
ES.5.3 Other Environmental Documents ........................................................... 10
ES.6 ALTERNATIVES DEVELOPMENT AND EVALUATION ......................................... 11
ES.6.1 Project Objectives and Evaluation Criteria ............................................ 11
ES.6.2 Preliminary Alternatives ......................................................................... 11
ES.6.3 Initially Proposed Sites .......................................................................... 13
ES.6.4 Final Sites and Alternatives ................................................................... 18
ES.7 PROPOSED ALTERNATIVE................................................................................... 22
ES.7.1 Wastewater Treatment Facility .............................................................. 22
ES.7.2 Wastewater Conveyance System .......................................................... 24
ES.7.3 Treated Effluent Outfall .......................................................................... 24
ES.7.4 Project Phasing Scenarios..................................................................... 24
ES.7.5 Phase 1 Cost Summary ......................................................................... 26
ES.8 IMPLEMENTATION PLAN ...................................................................................... 28
ES.8.1 Financial Analysis Summary .................................................................. 28

CAROLLO ENGINEERS i DRAFT – March 2013

LIST OF TABLES

Table ES.1 Population Projections ................................................................................... 5
Table ES.2 Current Flows and Loads............................................................................... 6
Table ES.3 Projected Flows and Loads ........................................................................... 7
Table ES.4 Effluent Quality Goals .................................................................................... 8
Table ES.5 Windjammer Vicinity MBR Key Considerations ........................................... 21
Table ES.6 Crescent Harbor North MBR Key Considerations ....................................... 21
Table ES.7 Crescent Harbor North AS Key Considerations........................................... 22
Table ES.8 Phase 1 Capacity Summary ........................................................................ 26
Table ES.9 Total Phase 1 Cost Comparison (in millions)............................................... 28
Table ES.10 City Share of Phase 1 Capital Costs (escalated, in millions) ....................... 30

LIST OF FIGURES

Figure ES.1 Study Area, Topography, and Existing System ............................................. 3
Figure ES.2 Growth Scenarios for Phasing ....................................................................... 9
Figure ES.3 Project Objectives ........................................................................................ 12
Figure ES.4 Potential WWTP Sites ................................................................................. 14
Figure ES.5. TBL+ Analysis of Preliminary Alternatives ................................................... 15
Figure ES.6 Six Sites For Further Evaluation .................................................................. 16
Figure ES.7 TBL+ Analysis of Refined Alternatives ........................................................ 17
Figure ES.8 Windjammer Vicinity Charrette Results ....................................................... 19
Figure ES.9 Crescent Harbor North Charrette Results.................................................... 20
Figure ES.10 Treatment Process Flow Schematic ............................................................ 23
Figure ES.11 Conveyance Improvements for Scenario 1.................................................. 25
Figure ES.12 Estimated Phase 1 Project Costs ................................................................ 27
Figure ES.13 Proposed Schedule ..................................................................................... 29
Figure ES.14 Monthly Sewer Rate Analysis ...................................................................... 31

CAROLLO ENGINEERS ii DRAFT – March 2013

Acronyms & Abbreviations
AA annual average
AACE Associate of the Advancement of Cost Engineering
AAF average annual flow
AC asbestos cement
ADA Americans with Disability Act
AS Activated Sludge
BAF Biologically Aerated Filter
BOD biochemical oxygen demand
BWF base wastewater flow
CBD Central Business District
CCI Construction Cost Index
CCP concrete cylinder pipe
CDBG Community Development Block Grant
CERB Community Economic Revitalization Board
CFR Code of Federal Regulations
City City of Oak Harbor
CMP corrugated metal pipe
DHAP Department of Archaeology & Historic Preservation
DI ductile iron
DIN dissolved inorganic nitrogen
DMR discharge monthly report
DNS determination of nonsignificance
DO dissolved oxygen
DOH Washington State Department of Health
DS determination of significance
DWF dry weather flow
Ecology Washing State Department of Ecology
EDC endocrine disrupting compuonds
EFH essential fish habitat
EID Environmental Information Document
EIS Environmental Impact Statement
ENR Engineering News-Record
EPA Environmental Protection Agency

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F/M ratio food-microorganism ratio
FDA Food and Drug Administration
GMA Growth Management Act
gpad gallons per are per day
gpcd gallons per capita per day
gpd gallons per day
gpd/sf gallons per day per square foot
gpm gallons per minute
GT gravity thickener
HDPE high –density polyethylene
hp horsepower
HPA Hydraulic Project Approval
HRT hydraulic retention time
IFAS integrated fixed film activated sludge
I/I Infiltration and inflow
JARPA Joint Aquatic Resources Permit Application
JPA Joint Planning area
Lagoon Plant Seaplane Base Lagoon WWTP
LOTT Lakehaven, Olympia, Tacoma, Tumwater area
MBR membrane bioreactor
MBBR moving bed bioreactor
MDNS mitigated determination of nonsignificance
mg/L milligrams per liter
mgd millions of gallons per day
MHHW mean higher high water
MHI median household income
MLE Modified Ludzack Ettinger
MLLW mean lower – low water
MLR mixed liquor return
MLSS mixed liquor suspended solids
MM maximum month
MMF maximum month flow
MR Marine Reach

CAROLLO ENGINEERS ii DRAFT – March 2013

NAS Naval Air Station
NH3 ammonia
NHPA National Historic Preservation Act of 1966
NOAA National Oceanic and Atmospheric Administration
NPDES National Pollutions Discharge Elimination System
NRDC Natural Resources Defense Council
NTU nephelometric turbidity units
NWCAA Northwest Clean Air Agency
O&M Operation and Maintenance
OHMC Oak Harbor Municipal Code
OS Open Space
PBP Planned Business Park
PD peak day
PDF peak day flow
PF public facilities
pH chemical balance measurement
PHF peak hour flow
PIP Planned Industrial Park
Plan Facilities Plan
POTW publicly owned treatment works
pp pounds per day
ppcd pounds per capita per day
ppd pounds per day
PRE Planned Residential Estate
PVC polyvinyl chloride
PWTF Public Works Trust Fund
RBC Rotating biological contactor
RCP reinforced concrete pipe
ROW right-of-way
SDC system development charges
SERP State Environment Review Process
SLR solids loading rate
SOR surface overflow rate

CAROLLO ENGINEERS iii DRAFT – March 2013

SRF State Revolving Fund
SRT solids retention time
STAG State and Tribal Assistance Grants
SVI sludge volume index
TBL+ Triple Bottom Line Plus Technical
TF Trickling Filter
TF/SC Trickling Filter/Solids Contact
TIN total inorganic nitrogen
TMDL total maximum daily load
TOrC trace organic chemical
TSS total suspended solids
UFC Uniform Fire Code
UGA Urban growth area
USEDA United States Economic Development Administration
USDA-RD United States Department of Agriculture-Rural Development
UV ultraviolet
UVT ultraviolet transmittance
VFD variable frequency drive
VFW Veterans of Foreign Wars
WAC Washington Administrative Code
WDFW table 6.8
WDNR Washington State Department of Natural Resources
WSEC Washington State Energy Code
WWTP Wastewater treatment plant

CAROLLO ENGINEERS iv DRAFT – March 2013

Executive Summary

ES.1 INTRODUCTION
The City of Oak Harbor (City) must replace two aging wastewater treatment facilities with a
new facility that meets modern standards for reliability and performance. This Wastewater
Facilities Plan (Plan) describes the proposed alternative for wastewater collection,
treatment, and effluent discharge (marine and/or reclamation), in accordance with
Washington Administrative Code (WAC) 173-240. Completing the projects recommended in
this Plan will allow the City to provide continued reliable wastewater service to the
community of Oak Harbor while protecting and preserving the surrounding environment.

ES.1.1 Project Need
The City’s wastewater system serves approximately 24,000 people within the City and the
Navy Seaplane Base. Wastewater is currently treated at two facilities: a rotating biological
contactor (RBC) facility near Windjammer Park, and a lagoon facility on the Navy’s
Seaplane Base. A project is needed to replace the City’s two existing treatment facilities
with a modern facility capable of meeting the objectives listed below. Although the existing
facilities are currently able to meet the requirements of the City’s National Pollution
Discharge Elimination System (NPDES) Permit, they are not able to provide reliable long-
term service for a number of reasons:
 The existing RBC facility is nearing the end of its useful life.
 Both the RBC and Lagoon Plants lack the technology to meet increasingly stringent
water quality standards, and have inadequate capacity to keep pace with anticipated
population growth.

 Both effluent outfalls have seen major failures; the RBC Oak Harbor outfall no longer
functions and the Crescent Harbor outfall is functional but damaged.

 The area surrounding the Seaplane Base Lagoon Plant was reclaimed as a saltwater
marsh in 2009. The lagoons are now surrounded by environmentally sensitive areas
and are subject to frequent high water conditions, making expansion or modifications
to the new lagoons infeasible.

ES.1.2 Project Goal
The goal of this project is to “obtain the highest level of water quality practical while
recognizing the limitations of the rate payers of the City to fund the improvements.” Specific
project objectives include:
1. Providing continued reliable wastewater treatment service;
2. Meeting high standards for water quality;

CAROLLO ENGINEERS ES-1 DRAFT – March 2013
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3. Allowing phased expansion to meet future demands; and
4. Delivering construction and operation of a new facility by 2017 in a cost-effective
manner.

ES.2 PLANNING AREA CHARACTERISTICS
The City of Oak Harbor is located near the northern end of Whidbey Island in Island
County, Washington. The United States Navy operates two bases on Whidbey Island: the
Seaplane Base located in the eastern portion of the City, and Ault Field which lies to the
north of the City. The City covers approximately 6,030 acres (9.4 square miles), of which
2,820 acres (4.4 square miles) is occupied by the Navy’s Seaplane Base. The City’s Urban
Growth Area (UGA) includes all of the City of Oak Harbor, as well as unincorporated areas
to the north, between the City and Ault Field, and to the south and west of the City. The
UGA represents the vicinity that is likely to be needed to accommodate growth over the
next 20 years.

ES.2.1 Service Area
Figure ES.1 shows the study and service areas for this Plan, which includes all of the UGA,
encompassing 7,540 acres (11.8 square miles) of land. A Joint Planning Area (JPA) which
includes areas that may be developed beyond the 20-year planning period is not included
in the study area, as these areas are not expected to require City sewer service within the
next 20 years. An estimated 136 households within the current city limits are not connected
to the City’s sewer system and are using on-site sewer systems. This equates to less than
two percent of the City’s population. For the purpose of estimating future flows and loads,
this Plan assumes that all currently unsewered areas will be served by the City within the
20-year planning horizon.

ES.3 EXISTING FACILITIES
The locations of the City’s existing wastewater facilities are shown in Figure ES.1. Existing
facilities include two treatment plants, two effluent outfalls, approximately 74 miles of pipe,
and 11 wastewater lift stations.

ES.3.1 Existing Treatment Facilities
Wastewater flows and loads treated at the City’s existing RBC Plant are approaching
permitted limits, triggering the need for this Plan. Portions of the RBC Plant are over 50
years old and have reached the end of their service life. In recent years the City has
experienced an increasing number of mechanical failures at the RBC Plant, particularly for
outdated treatment equipment that is no longer prevalent in the treatment industry. Various
analyses completed prior to this Plan have concluded that there is little or no salvage value
in the existing RBC Plant. Due to its age and condition, and an inability to meet future


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regulatory requirements using installed technology, alternatives presented in this Plan
assume the existing RBC Plant will be abandoned and demolished.

The Seaplane Base Lagoon Plant (Lagoon Plant) was constructed and originally operated
by NAS Whidbey to serve the Seaplane Base. In 1990 the City secured a 50-year lease
from the Navy to operate the Lagoon Plant. Wastewater flows and loads treated at the
Lagoon Plant are approaching permitted limits, triggering the need for this Plan. The current
lagoon treatment process does not provide sufficient capacity to accommodate projected
City growth. A capacity increase at the lagoons will trigger more stringent effluent standards
that cannot be met with conventional lagoon treatment. Expansion or modification of the
existing lagoons is infeasible due to surrounding environmentally sensitive areas. Due to
capacity limitations, an inability to meet future regulatory requirements, access issues
during flood events, and surrounding environmentally sensitive areas, alternatives
presented in this Plan assume the existing Lagoon Plant will not be used in the future to
treat wastewater from the City’s collection system.

ES.3.2 Existing Effluent Outfalls
Historically, effluent treated at the RBC Plant was discharged through an 18-inch diameter
corrugated metal pipe outfall and diffuser into Oak Harbor, terminating at approximately
minus 15 feet mean lower low water (MLLW). The diffuser has had a history of sediment
buildup and blockage. In the summer of 2010 a significant portion of the diffuser was found
to be filled with sediments. In September 2010 the outfall failed and was abandoned. Since
that time all flow treated at the RBC Plant has been pumped to the Lagoon Plant.

Effluent treated at the Lagoon Plant is currently discharged through an 18-inch diameter
concrete pipe outfall and diffuser into Crescent Harbor, terminating at approximately minus
15 feet MLLW. The outfall was inspected in October 2010. Several sections of leaking pipe
and joints were identified at that time. Portions of the pipe and diffuser will need to be
repaired, replaced, and up-sized if the outfall is used as a component of the City’s future
wastewater system.

ES.3.3 Existing Wastewater Collection System
The collection system was analyzed in previous planning efforts to determine the capacity
of the existing network and to identify other issues that would trigger upgrades or
improvements over the next 20 years. The results indicate a maximum peak hour flow of
7.9 million gallons per day (mgd) would be generated in the collection system discharging
to the City’s existing RBC plant. Additionally, approximately 2 mgd of peak flow is
generated on the Seaplane Base. The sum of these peak hour flows (9.9 mgd) provides the
basis for peak hydraulic treatment capacity under current conditions.


Potential capacity limitations were identified in portions of the sewer system, and certain
segments of the existing collection system were identified as being under-capacity for
current flows. However, no segments require upgrades in the initial years of planning
unless flow from the Navy is routed to existing gravity pipe segments that are near capacity.
The timing for collection system capacity improvements is evaluated as a component of the
alternatives analysis presented in this Plan.

ES.4 WASTEWATER FLOWS AND LOADS
Influent flow is derived from residential and commercial sources that discharge to the City’s
RBC Plant, and from the Seaplane Base. There are no significant industrial sources in the
City’s service area. Existing data were analyzed to determine current flows and loads on a
total and per-capita basis. Future flows and loads were projected using current per-capita
values and estimates for future population that are consistent with the City’s comprehensive
planning documents.

ES.4.1 Flow and Load Projections
Existing and projected population data are shown in Table ES.1. Current wastewater flows
and loads are shown in Table ES.2 and project wastewater flows and loads are shown in
Table ES.3.

Table ES.1 Population Projections
City of Oak Harbor
Navy Seaplane
Year City UGA Sewered(2) Total
Base(1)
2000 15,395(3) 4,400 0 19,795(4)
2010 17,675(3) 4,400 0 22,075(4)
2030 23,776 4,400 731 28,907
2060 36,654 4,400 1,637 42,691
Notes:
(1) Summarized from the City of Oak Harbor Comprehensive Sewer Plan (Tetra Tech,
December 2008) Table 3-2.
(2) Assumes the UGA is not served currently and will be linearly incorporated into the service
area from 2012 through 2060.
(3) Total flow minus Navy flow.
(4) US Census data (2010).


Table ES.2 Current Flows and Loads
City of Oak Harbor
Parameter City Total
Flow, mgd(1)
BWF 1.4 1.8
AAF 1.7 2.1
MMF 2.3 3.0
PDF 3.4 4.7
PHF 7.9 9.9
BOD, ppd(2,3)
AA 3,556 4,127
MM 4,412 5,049
PD 5,556 6,510
TSS, ppd(2,4)
AA 2,931 3,371
MM 4,153 4,792
PD 7,383 8,373
NH3, ppd(2,5)
AA 390 487
MM 470 586
PD 596 745
Notes:
(1) Total flow includes both City flow and flow from Navy facilities. Since the Navy population is
projected to remain constant through 2060, the Navy flows are projected to equal 0.37 mgd for
BWF, 0.43 mgd for AAF, 0.65 mgd for MMF and 1.23 for PDF.
(2) Total load includes load from both the City and the Navy facilities.
(3) The Navy BOD load is projected to equal 514 ppd for AA, 732 ppd for MM, and 942 for PD.
(4) The Navy TSS load is projected to equal 440 ppd for AA, 638 ppd for MM, and 990 ppd for PD.
(5) The Navy NH3 load is projected to equal 84 ppd for AA, 110 ppd for MM, and 128 ppd for PD.


Table ES.3 Projected Flows and Loads
City of Oak Harbor
2030 2060
Parameters
City Total City Total
(1)
Flow, mgd
BWF 1.9 2.3 3.0 3.4
AAF 2.4 2.8 3.7 4.1
MMF 3.2 3.9 5.0 5.7
PDF 4.6 6.0 7.4 8.6
PHF 9.0 11.0 11.4 13.4
BOD, ppd(2,3)
AA 4,931 5,444 7,704 8,217
MM 6,117 6,849 9,557 10,290
PD 7,704 8,646 12,037 12,979
TSS, ppd(2,4)
AA 4,064 4,504 7,704 6,789
MM 5,759 6,397 9,557 9,636
PD 10,237 11,227 12,037 16,984
NH3, ppd(2,5)
AA 541 638 845 942
MM 651 768 1,017 1,134
PD 827 975 1,292 1,440
Notes:
(1) Total flow includes both City flow and flow from Navy facilities. Since the Navy population is
projected to remain constant through 2060, the Navy flows are projected to equal 0.37 mgd for
BWF, 0.43 mgd for AAF, 0.65 mgd for MMF and 1.23 for PDF.
(2) Total load includes load from both the City and the Navy facilities.
(3) The Navy BOD load is projected to equal 514 ppd for AA, 732 ppd for MM, and 942 for PD.
(4) The Navy TSS load is projected to equal 440 ppd for AA, 638 ppd for MM, and 990 ppd for PD.
(5) The Navy NH3 load is projected to equal 84 ppd for AA, 110 ppd for MM, and 128 ppd for PD.

Population projections for the City are based on the City’s Draft Water System Plan. Navy
population (and associated flows and loads) on the Seaplane Base are assumed to be
constant over the planning period. Future flow and load projections also assume that the
UGA will be uniformly incorporated into the sewer service area by Year 2060.

ES.4.2 Phasing Scenarios For Growth
Throughout this planning effort, year 2060 flows and loads are used to determine “ultimate”
land area requirements for a WWTP that will serve the City’s needs well into the future.
Year 2030 flows and loads are used to size and compare alternatives on a capital and life-
cycle cost basis. The actual rate of growth of the City’s population, and corresponding
increases in flows and loads, will likely be different than the values used for planning. To


account for these potential differences, phasing options are developed for the selected
alternative to achieve the right balance between reliable capacity and affordability. Figure
ES.2 shows the range of growth scenarios used for this analysis. Phase 1 facilities
proposed in this Plan are based on the moderate growth scenario (approximately one
percent annual growth in City population).

ES.5 REGULATORY REQUIREMENTS
Recognizing that the City is connected to the waters of Puget Sound via Oak Harbor and
Crescent Harbor, the City’s goal is to obtain the highest level of water quality practical while
recognizing the limitations of the rate payers of the City to fund improvements. A primary
goal of the City is the continued protection of the water quality of the waters in and around
Oak Harbor, thereby meeting the goals outlined in the Puget Sound Action Plan developed
by the Puget Sound Partnership for the Cleanup and Protection of Puget Sound.

ES.5.1 Effluent Quality Goals
The City has established the effluent quality goals for conventional pollutants that are more
stringent than the City’s current NPDES permit limits. These effluent goals are summarized
in Table ES.4.

Table ES.4 Effluent Quality Goals
City of Oak Harbor
RBC Plant NPDES Lagoon Plant New Facilities
Permit Limit NPDES Permit Limit Target / Goal
TSS 30 mg/L 75 mg/L 10 mg/L
85% removal 85% removal 95% removal
CBOD5 25 mg/L 25 mg/L 10 mg/L
85% removal 85% removal 95% removal
Turbidity Not applicable Not applicable 1 NTU
Chlorine Residual 0.114 mg/L 0.5 mg/L No discharge
Fecal Coliform 200/100 mL 200/100 mL 100/100 mL


4.5
Measured Data
Scenario 1, No Growth
4.0
Scenario 2, Intermediate Growth
Scenario 3, Comprehensive Plan
3
3.5
2
1
3.0

2.5

2.0

Maximum Month Flow, mgd
1.5

1.0 Notes:
1
1:  Current measured capacity is 3.0 mgd.
2
2:  Capacity required at projected year of startup (2017) ranges from 3.0 to 3.2 mgd.
0.5 3:  Assuming 3.4 mgd of capacity is constructed in Phase 1, years of service
3
(prior to Phase 2) range from 4 to 13 years.

0.0
2000 2005 2010 2015 2020 2025 2030 2035

GROWTH SCENARIOS
FOR PHASING
FIGURE ES.2

CITY OF OAK HARBOR

pw://Carollo/Documents/Client/WA/Oak Harbor/8549A00/Deliverables/Facilities Plan/Fig_ES_02.docx

Alternatives are evaluated largely on their ability to meet current NPDES permit limits.
However, the flexibility to adapt to future regulatory requirements is an important planning
consideration for the City. Potential future NPDES permit limits considered in this analysis
include the ability to meet nutrient (nitrogen) limits and potential future trace organic
chemical (TOrC) limits. While it is not yet clear how Ecology will establish future limits on
these or other parameters, a number of Western Washington municipalities have begun to
evaluate future nitrogen removal. In evaluating alternatives for Oak Harbor, the City is
considering the need to meet a TIN level of 8 mg/L in the future, should these limits be
enforced in subsequent permit cycles. Also, the City is interested in technologies that have
demonstrated some ability to reduce TOrC concentrations in treated effluent, such as the
MBR process or AS process with an extended solids residence time (SRT).

ES.5.2 Biosolids Management
The federal document that regulates the use and disposal of sewage sludge is the CFR,
Part 503 (40 CFR §503, EPA 1993). Land-applied biosolids must meet requirements in the
Part 503 regulations for reducing pathogens and vector attraction. The rule establishes two
basic classes for pathogen reduction: Class A and Class B. The City is considering
alternatives that will meet the 503 requirements for Class B initially, and Class A in future
phases.

ES.5.3 Other Environmental Documents
The City has adopted the policies of the State Environmental Policy Act (SEPA) by
reference (OHMC 20.04.010). A SEPA review will be completed to ensure that there are no
adverse environmental impacts from proposed projects. The City will issue a threshold
determination as to whether significant environmental impact may be expected as a result
of the projects recommended by this Plan. This determination will be sent to Ecology for
concurrence.

To be eligible for financial assistance from the State Water Pollution Control Revolving
Fund, this Plan must also comply with the State Environmental Review Process (SERP;
WAC 173-98-100). The SERP was established “to help ensure that environmentally sound
alternatives are selected and to satisfy the state’s responsibility to help ensure that
recipients comply with the NEPA and other applicable environmental laws, regulations, and
executive orders.” Other environmental components of this Plan include a Biological
Assessment (BA) that will be submitted to the Corps of Engineers, as well as documents
prepared in accordance with Section 106 of the National Historic Preservation Act (NHPA).


ES.6 ALTERNATIVES DEVELOPMENT AND EVALUATION
Alternatives presented in this Plan are comprised of three components: 1) a Wastewater
Treatment Process; 2) an Effluent Discharge (Outfall) Location; and 3) a Wastewater
Treatment Facility Site. At the onset of the Project, the City took a position that all sites,
outfall locations, and treatment processes should be considered potentially viable.

The project team used a comprehensive process to develop project objectives and
evaluation criteria; and to identify and screen alternatives. The process generally consisted
of major milestones between December 2010 and August 2012. Community input was a
critically important factor in the development, evaluation and selection of alternatives. The
City began proactively working with stakeholders in November of 2010 and continues to
integrate a high level of community input to implement the proposed alternative.

ES.6.1 Project Objectives and Evaluation Criteria
The City’s 2009 Comprehensive Plan states that the City “…recognizes the value of its
natural environmental and supports environmental protection and enhancement. The
community recognizes that total preservation may not be feasible in an urban area. Rather,
the City should seek to implement environmental goals within the context of planned
growth.” To reflect the City’s values, the project team evaluated alternatives for upgrading
the City’s wastewater treatment system considering impacts and benefits of the project to
the community as a whole. The Triple Bottom Line is a commonly used approach that
weighs three areas of cost and benefit: financial, social, and environmental. The category of
“Technical” was included in this analysis to address industry standards in related to
performance, implementability, operations, and maintenance. The approach of combining
these four perspectives is referred to herein as “TBL+”.

For this evaluation, each of the four TBL+ categories was divided into three, equally
weighted objectives. City staff meetings, stakeholder workshops, and community interviews
were completed to establish project objectives and evaluation criteria for comparing
alternatives. A summary of the TBL+ objectives and criteria is illustrated in Figure ES.3.

ES.6.2 Preliminary Alternatives
After a preliminary evaluation, the City selected two wastewater treatment processes as the
basis for alternatives development: a membrane bioreactor (MBR) process and an
activated sludge (AS) process with tertiary treatment. Analysis of outfall locations was also
completed early in the Project. Oak Harbor was determined to be the most cost-effective
and preferred location, largely to eliminate the risk of impact fees that could be assessed
through the aquatic land use lease process. Once these decisions had been made, the
process of developing and evaluating alternatives was focused on selecting a site for the
City’s new treatment facility.


PROJECT OBJECTIVES
FIGURE ES.3

CITY OF OAK HARBOR

pw://Carollo/Documents/Client/WA/Oak Harbor/8549A00/Deliverables/Facilities Plan/Fig_ES_03.docx

ES.6.3 Initially Proposed Sites
In December 2010, stakeholder and community input was used to identify 22 sites
illustrated by the yellow dots on Figure ES.4. Two additional sites were added based on
public input received later in the process (illustrated by yellow triangles on the figure). Over
the next several months the Project team considered public input and technical criteria to
develop 13 preliminary alternatives on eight potential sites, shown in blue on Figure ES.4.

Following the March 2011 City Council meeting, the project team completed an initial TBL+
evaluation of 13 preliminary alternatives (shown in Figure ES.5), generated by combining
the eight potential sites with the two potential treatment processes options, each
discharging to Oak Harbor. In the spring of 2011, additional coordination between the City
and US Navy resulted in one previously identified site (Crescent Harbor) being added back
to the list of potential sites. Over the next six months, the Project team conducted a series
of public involvement efforts additional technical analysis, and coordination with the US
Navy. During this time, the City was approached by the owners of property inside of the
UGA and adjacent to Crescent Harbor Drive. As a result of the discussions that followed,
the City elected to add this site (Crescent Harbor North) to the sites being considered.
Figure ES.6 shows the six sites proposed for further evaluation. They include:
 Windjammer Park
 Marina/Seaplane Base
 Old City Shops
 Beachview Farm
 Crescent Harbor
 Crescent Harbor North

To better illustrate differences between the six sites being considered further, the TBL+
analysis was modified to compare all alternatives on an equal basis (i.e. assuming MBR
process discharging treated effluent to Oak Harbor). Figure ES.7 shows the modified TBL+
comparison of the refined alternatives. Based on this analysis, the City elected to complete
a more detailed comparison of three final alternatives:

 Windjammer Vicinity MBR
 Crescent Harbor North MBR
 Crescent Harbor North AS


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