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Comprehensive Sewer Plan
Prepared for
City of Auburn, Washington
October 19, 2015
701 Pike Street, Suite 1200
Seattle, WA 98101-2310
Phone: 206-624-0100
Fax: 206-749-2200
Comprehensive Sewer Plan
Prepared for
City of Auburn, Washington
October 19, 2015
v
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Table of Contents
List of Figures ............................................................................................................................................... ix
List of Tables ................................................................................................................................................ x
List of Abbreviations .................................................................................................................................... xi
Executive Summary ............................................................................................................................... ES-1
ES.1 LOS Goals ............................................................................................................................. ES-2
ES.2 Evaluation of the Sewer Utility ............................................................................................ ES-3
ES.3 Implementation Plan ........................................................................................................... ES-3
ES.3.1 6-Year and 20-Year CIP ......................................................................................... ES-3
ES.3.2 Monitoring .............................................................................................................. ES-6
ES.3.3 Asset Management and Maintenance and Operations ...................................... ES-6
1. Introduction .........................................................................................................................................1-1
1.1 Purpose and Objectives ..........................................................................................................1-1
1.2 Document Organization ..........................................................................................................1-2
2. Background .........................................................................................................................................2-1
2.1 Previous Auburn Comprehensive Sewer Plans .....................................................................2-1
2.2 City Comprehensive Plan........................................................................................................2-1
2.3 Sanitary Sewer Service Area ..................................................................................................2-1
2.4 Existing Land Use Plans .........................................................................................................2-1
2.4.1 King County Comprehensive Plan ...........................................................................2-1
2.4.2 King County Regional Wastewater Services Plan ...................................................2-2
2.4.3 City of Auburn Water Resources Protection Report ...............................................2-7
2.5 Neighboring Sewer Utilities ....................................................................................................2-7
2.5.1 Soos Creek Water and Sewer District and City of Kent .........................................2-7
2.5.2 City of Pacific ............................................................................................................2-7
2.5.3 Muckleshoot Indian Tribe Reservation ...................................................................2-7
2.5.4 Lakehaven Utility District .........................................................................................2-8
2.5.5 City of Algona ............................................................................................................2-8
2.5.6 City of Bonney Lake ..................................................................................................2-8
2.5.7 King County ...............................................................................................................2-8
3. Wastewater System Policies ..............................................................................................................3-1
3.1 Sewer Comprehensive Plan Policies, Standards, and Guidelines .......................................3-1
3.2 City Comprehensive Plan and Auburn City Code Goals and Policies ...................................3-1
3.3 Sanitary Sewer Level of Service .............................................................................................3-1
3.4 Business Practices Policy .......................................................................................................3-1
4. Description of Existing System ..........................................................................................................4-1
4.1 Overview ..................................................................................................................................4-1
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4.1.1 Valley Sewer Basin ...................................................................................................4-1
4.1.2 West Hill Sewer Basin ..............................................................................................4-1
4.1.3 Lea Hill Sewer Basin .................................................................................................4-2
4.1.4 Auburn Way South Sewer Basin ..............................................................................4-2
4.1.5 South Hill Sewer Basin .............................................................................................4-2
4.2 Sanitary Sewer Facilities ........................................................................................................4-2
4.2.1 Critical Infrastructure ...............................................................................................4-7
4.2.2 Pump Stations ..........................................................................................................4-7
4.2.3 Gravity and Force Main Collection System .............................................................4-8
4.2.4 Side Sewer Laterals..................................................................................................4-8
4.2.5 River Crossings .........................................................................................................4-8
4.3 King County Conveyance ..................................................................................................... 4-12
4.4 Infiltration and Inflow ........................................................................................................... 4-12
4.5 Industrial Waste Discharges ............................................................................................... 4-12
4.6 Water Reclamation and Reuse ........................................................................................... 4-14
4.6.1 Regulatory Framework .......................................................................................... 4-14
4.6.2 Potential Reclaimed Water Sources ..................................................................... 4-14
4.6.3 Potential Reclaimed Water Users ......................................................................... 4-15
4.6.4 Reclaimed Water Summary .................................................................................. 4-16
5. Wastewater System Analysis .............................................................................................................5-1
5.1 Hydraulic Capacity Analysis ....................................................................................................5-1
5.1.1 Hydrologic and Hydraulic Model ..............................................................................5-1
5.1.2 Assessment Criteria .................................................................................................5-1
5.1.3 Existing-Conditions Evaluation ................................................................................5-2
5.1.4 Future-Conditions Evaluation ..................................................................................5-4
5.2 Inflow and Infiltration ........................................................................................................... 5-11
5.2.1 Initial Inflow and Infiltration Assessment ............................................................. 5-11
5.3 Sewer Extensions ................................................................................................................. 5-15
5.4 Asset Management .............................................................................................................. 5-21
6. Maintenance and Operations ............................................................................................................6-1
6.1 Utility Responsibility and Authority ........................................................................................6-1
6.1.1 Organizational Structure ..........................................................................................6-1
6.1.2 Staffing Level ............................................................................................................6-2
6.1.3 Level of Service ........................................................................................................6-3
6.1.4 Operator Training and Education ............................................................................6-3
6.2 Routine Operations .................................................................................................................6-3
6.2.1 Pump Station Maintenance .....................................................................................6-3
6.2.2 Collection System Maintenance ..............................................................................6-5
6.2.3 Field Operations .......................................................................................................6-6
6.3 Fats, Oils, and Grease Reduction Program ...........................................................................6-6
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6.4 Non-Routine and Emergency Operations ..............................................................................6-7
6.4.1 Customer Service Requests ....................................................................................6-7
6.4.2 Emergency Response Program ...............................................................................6-8
6.5 Communications, Data Collection, and Record-Keeping .....................................................6-8
6.5.1 Telemetry and Pump Station Controls ....................................................................6-8
6.5.2 Data Collection and Record-Keeping ......................................................................6-9
6.6 Existing Staffing Requirements ........................................................................................... 6-10
6.7 Potential Improvement Opportunities and Capital Needs ................................................ 6-11
7. Recommended Plan ...........................................................................................................................7-1
7.1 Capital Improvement Program ...............................................................................................7-1
7.1.1 Project Priority...........................................................................................................7-2
7.1.2 Project Cost ...............................................................................................................7-2
7.2 Project Summary.....................................................................................................................7-2
8. Finance ................................................................................................................................................8-1
8.1 Past Financial Performance ...................................................................................................8-1
8.1.1 Statement of Revenues, Expenses, and Changes in Net Position ........................8-1
8.1.2 Statement of Net Position ........................................................................................8-2
8.1.3 Outstanding Debt Principal ......................................................................................8-5
8.2 Available Capital Funding Resources ....................................................................................8-5
8.2.1 Internal Utility Resources .........................................................................................8-5
8.2.2 Government Programs and Resources ...................................................................8-7
8.2.3 Public Debt Financing ..............................................................................................8-9
8.2.4 Capital Resource Funding Summary .................................................................... 8-10
8.3 Financial Plan ....................................................................................................................... 8-10
8.3.1 Utility Fund Structure ............................................................................................ 8-11
8.3.2 Financial Policies ................................................................................................... 8-11
8.3.3 Capital Funding Plan ............................................................................................. 8-12
8.4 Financial Forecast ............................................................................................................... 8-14
8.4.1 Cash Flow Test ....................................................................................................... 8-14
8.4.2 Coverage Test ........................................................................................................ 8-14
8.4.3 Financial Forecast ................................................................................................. 8-14
8.4.4 City Funds and Reserves Balances ...................................................................... 8-17
8.5 Existing Rate Structure and Projected Schedule ............................................................... 8-17
8.6 Affordability .......................................................................................................................... 8-18
8.7 Conclusion ............................................................................................................................ 8-19
9. Implementation Plan ..........................................................................................................................9-1
9.1 6-Year and 20-Year CIP ..........................................................................................................9-1
9.2 Monitoring ...............................................................................................................................9-2
9.3 Asset Management and Maintenance and Operation .........................................................9-3
9.3.1 Collect Asset Data ....................................................................................................9-3
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9.3.2 Criticality ...................................................................................................................9-7
9.3.3 Defining Maintenance Strategies ............................................................................9-7
9.3.4 Condition Assessments ............................................................................................9-9
9.3.5 Continual Improvement ........................................................................................ 9-10
9.4 Discharge Quality Control .................................................................................................... 9-10
9.4.1 Control of Fats, Oils, and Greases ........................................................................ 9-10
9.4.2 Industrial Waste..................................................................................................... 9-10
9.4.3 Public Education .................................................................................................... 9-10
9.5 Hazard Planning ................................................................................................................... 9-11
9.6 Maintenance Issues ............................................................................................................ 9-11
9.6.1 105th Place SE and Lea Hill Road SE .................................................................. 9-11
9.6.2 Sewers Crossing Freeway ..................................................................................... 9-11
9.6.3 Sewers within Easements ..................................................................................... 9-11
9.7 SEPA Compliance ................................................................................................................. 9-11
9.8 Schedule............................................................................................................................... 9-11
10. Limitations ................................................................................................................................... 10-1
11. References ................................................................................................................................... 11-1
Inter-local Agreements and Outside Agency Correspondence .......................................... A-1 Appendix A:
Hydraulic Capacity Analysis ................................................................................................ B-1 Appendix B:
Pump Station Information ....................................................................................................C-1 Appendix C:
SEPA Compliance ................................................................................................................ D-1 Appendix D:
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List of Figures
Figure ES-1. Implementation schedule ................................................................................................ ES-7
Figure 2-1. Vicinity .....................................................................................................................................2-3
Figure 2-2. Plan study area ......................................................................................................................2-5
Figure 4-1. Sewer service basins .............................................................................................................4-3
Figure 4-2. Existing wastewater conveyance system .............................................................................4-5
Figure 4-3. Critical sewers ........................................................................................................................4-9
Figure 4-4. City of Auburn collection system summary statistics ....................................................... 4-11
Figure 4-5. Potential reclaimed water users within Auburn city limits ............................................... 4-17
Figure 5-1. HGL for surcharged condition ...............................................................................................5-2
Figure 5-2. Wastewater model network and results: existing conditions, 20-year flow .......................5-5
Figure 5-3. Wastewater model network and results: future conditions, 20-year flow ..........................5-9
Figure 5-4. Primary components of an I/I management program ...................................................... 5-12
Figure 5-5. Inflow and infiltration comparative levels ......................................................................... 5-13
Figure 5-6. Existing and proposed sewer facilities .............................................................................. 5-17
Figure 5-7. Sewer extension for unsewered areas estimated costs .................................................. 5-19
Figure 6-1. City of Auburn Department of Community Development and Public Works
organizational chart ..........................................................................................................................6-2
Figure 7-1. CIP development flow chart ..................................................................................................7-1
Figure 9-1. Sanitary sewers with missing attribute information ............................................................9-5
Figure 9-2. Example of identifying asset criticality .................................................................................9-7
Figure 9-3. Maintenance strategies based on risk .................................................................................9-8
Figure 9-4. City of Auburn Sewer Plan implementation timeline ........................................................ 9-12
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List of Tables
Table ES-1. Utility Level of Service ........................................................................................................ ES-2
Table ES-2. Annual CIP Project Cost Summary .................................................................................... ES-5
Table 3-1. Sewer Comprehensive Plan Policies ......................................................................................3-2
Table 4-1. City of Auburn Sewer Pump Station Inventory .......................................................................4-7
Table 4-2. City of Auburn Industrial Waste Discharge Permits ........................................................... 4-13
Table 5-1. Simulated 20-Year Flows to Pumping Stations, Existing Conditions Scenario ...................5-4
Table 5-2. Simulated 20-Year Flows to Pumping Stations, Future (2020) Conditions Scenarioa .......5-8
Table 5-3. King County I/I Rates ........................................................................................................... 5-11
Table 6-1. Sewer Utility M&O Field Personnel .........................................................................................6-2
Table 6-2. Sewer System Maintenance and Operation Task Summary ............................................. 6-11
Table 7-1. Annual Project Cost Summary for 6-Year and 20-Year CIP ..................................................7-3
Table 8-1. City of Auburn Statement of Revenues, Expenses and Changes in Fund Net Position ......8-2
Table 8-2. City of Auburn Statement of Net Position ..............................................................................8-4
Table 8-3. City of Auburn Outstanding Debt Principal ............................................................................8-5
Table 8-4. City of Auburn Current System Development Charge Schedule ..........................................8-6
Table 8-5. Funding Programs ...................................................................................................................8-8
Table 8-6. City of Auburn Sewer CIP ..................................................................................................... 8-13
Table 8-7. City of Auburn Capital Financing Plan ................................................................................. 8-13
Table 8-8. City of Auburn Financial Forecast ....................................................................................... 8-16
Table 8-9. City of Auburn Cash Balance Summary .............................................................................. 8-17
Table 8-10. City of Auburn Projected Local Rate Schedule.................................................................. 8-18
Table 8-11. City of Auburn Affordability Test ........................................................................................ 8-18
Table 9-1. Annual Project Cost Summary for 6-Year CIP (in millions of dollars) ...................................9-1
Table 9-2. Cost Summary for 20-Year CIP (in millions of dollars) ..........................................................9-2
Table 9-3. Criticality-Based Maintenance Strategy Summary ................................................................9-9
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List of Abbreviations
ACC Auburn City Code
AMWA Association of Metropolitan Water
Agencies
APWA American Public Works Association
BAB Build America Bonds
bgs below ground surface
ccf 100 cubic feet
CCTV closed-circuit television
CDPW Community Development and Public
Works Department
CERB Community Economic Revitalization
Board
CFP Capital Facilities Program
CIP Capital Improvement Program
City City of Auburn
CMMS computerized maintenance
management system
Comp Plan City of Auburn Comprehensive
Plan
CSI Conveyance System Improvements
CSWD Criteria for Sewage Works Design
d/D depth to pipe diameter
DOH Washington State Department of Health
Ecology Washington State Department of
Ecology
Engineering Engineering Services Division
EPA U.S. Environmental Protection Agency
FOG fats, oils, and grease
fps foot/feet per second
FSE food service establishment
FTE full-time equivalent
GIS geographic information system
GO general obligation
gpad gallon(s) per acre day
gph gallons per hours
gpm gallon(s) per minute
H&H hydrologic and hydraulic
HDPE high-density polyethylene pipe
HGL hydraulic grade line
I/I inflow and infiltration
IT Innovation and Technology
LACP Lateral Assessment and Certification
Program
LEED Leadership in Energy and Environmental
Design
lf linear feet
LFC local facilities charge
LOS level of service
LUD Lakehaven Utility District
M&O maintenance and operations
MACP Manhole Assessment and Certification
Program
MBR membrane bioreactor
MIT Muckleshoot Indian Tribe
MUD Muckleshoot Utility District
NASSCO National Association of Sewer Service
Companies
PAA potential annexation area
PACP Pipeline Assessment and Certification
Program
PdM predictive maintenance
Plan Comprehensive Sewer Plan
PM preventive maintenance
psi pound(s) per square inch
PSRC Puget Sound Regional Council
PVC polyvinyl chloride
PWB Public Works Board
RCE residential customer equivalent
RCW Revised Code of Washington
R&R repair and replacement
RWSP Regional Wastewater Services Plan
SARA Superfund Amendments and
Reauthorization Act of 1986
SCADA supervisory control and data acquisition
SCAQMD South Coast Air Quality Management
District
SCWSD Soos Creek Water and Sewer District
SDC system development charge
SEPA State Environmental Policy Act
SOS Save Our Streets
SSO sanitary sewer overflow
SSSA sanitary sewer service area
ULID utility local improvement district
Utility Sanitary Sewer Utility
WAC Washington Administrative Code
WSDOT Washington State Department of
Transportation
WWCPA Washington Wastewater Collection
Personnel Association
ES-1
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Executive Summary
This Comprehensive Sewer Plan (Plan) for the City of Auburn, Washington (City) is an update to the
previous plan that was completed in December 2009 (Brown and Caldwell). This plan should be
considered a General Sewer plan under authority of WAC 173-250-050. Within this document,
Comprehensive Sewer Plan and General Sewer Plan should be considered the same. Evaluation of
the sanitary sewer system for this Plan incorporated a policy review; system-wide hydraulic modeling;
review and documentation of maintenance and operations (M&O) practices; and evaluation and
update of the Capital Improvement Program (CIP) to account for completed projects, changes in
system conditions, and new development, as well as to incorporate new financial information.
This Plan contains time frames that are the intended framework for future funding decisions and
within which future actions and decisions are intended to occur. However, these time frames are
estimates and, depending on factors involved in the processing of applications and project work, and
availability of funding, the timing may change from the included time frames. The framework does
not represent actual commitments by the City, which may depend on resources available.
The purpose of the Plan is to guide the City’s Sanitary Sewer Utility (Utility) with respect to future
activities and improvements for the Utility. To fulfill this stated purpose, the following objectives were
achieved:
• provide background information regarding development and planning of the Utility, the sanitary
sewer service area (SSSA), and neighboring utilities (Chapter 2)
• evaluate environmental, social, and regulatory drivers to develop level-of-service (LOS) goals for
capital facility infrastructure development, operation, maintenance, and other key elements of
utility management (Chapter 3)
• characterize the current sewer system and facilities (Chapter 4)
• perform a hydraulic modeling analysis to evaluate system capacity, review inflow and infiltration
(I/I), identify possible sewer extensions to provide City sewer service to the entire SSSA, and
provide a means to update the economic life model (Chapter 5)
• establish a baseline understanding of the proactive and responsive maintenance procedures to
evaluate Utility staffing and data collection needs (Chapter 6)
• develop a CIP based on the results of hydraulic and condition analyses by meeting required
customer service levels, effectively managing risks, and minimizing the City’s costs of sewer
asset ownership (Chapter 7)
• develop a funding plan that optimizes use of rates, system development charges (SDCs), and/or
other service fees based on projected Utility spending requirements and a review of funding
sources and City financial policies (Chapter 8)
• prioritize capital improvement projects and repair and replacement (R&R) activities to
accommodate both 6- and 20-year funding frameworks and create an implementation plan to
meet LOS goals (Chapter 9)
The following sections summarize the development of the Plan and outline the recommendations
contained in the implementation plan.
Executive Summary City of Auburn Comprehensive Sewer Plan
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ES.1 LOS Goals
LOS goals provide a framework for the Utility to assess its staffing levels, prioritize its resources,
justify its rate structure, and document its successes. It is important that LOS goals include clear
criteria to use in evaluating how well those goals are being met. LOS goals for the Utility that were
developed for this Plan are based on relevant City policies. LOS goals and associated City polices are
listed in Table ES-1.
Table ES-1. Utility Level of Service
Item* Policy, standard, or guideline statement
Planning considerations
6 The City will size gravity sewers for peak wet weather flow rates that include I/I flows. Gravity sewers will be sized to convey the
once-per-20-year peak hour flow without surcharging.
7 The City will size pump stations and force mains for peak wet weather flow rates that include I/I flows. Pump stations will be sized
to convey the once-per-5-year flow with one pump out of service and convey the once-per-20-year flow with all pumps in service.
Protection and improvement of the environment and public health
16 The City will comply with all federal, state, and local regulations in operation and maintenance of the City’s wastewater collection
and conveyance infrastructure.
17
The City will evaluate Utility activities to emphasize sustainability practices. City staff will identify specific areas to measure
sustainability. Examples could include weighing energy consumption impacts more heavily during capital project development,
selecting less impactful cleaning and maintenance products, and structuring maintenance activities to minimize vehicle travel
miles. While maintaining minimum flows for efficient operation of the system, water conservation will be practiced whenever
possible. City staff will benchmark practices and log changes.
18 The City will support the use of reclaimed water technologies where economically feasible. City staff will evaluate opportunities for
reclaimed water use and support initiatives where the benefits outweigh costs.
19 The City shall pursue I/I reduction for the purposes of eliminating or reducing required capacity upgrades and reducing
maintenance costs (to include reducing wear and tear on pump stations) when determined to be cost-effective.
Customer satisfaction
21
The City will evaluate and strive to maintain customer satisfaction with Utility service delivery.
• The City will create a baseline against which to evaluate future improvements:
• Annual assessment of complaints/citizen reports
• The City will communicate proactively with the community and stakeholders regarding wastewater service
improvements.
Utility financing
36
Appropriate rates and SDCs shall be assessed to fund the ongoing maintenance, operation, and capital expenditures of the Utility,
in accordance with the Comprehensive Wastewater Plan. Periodic (typically every 5 years) cost-of-service studies shall be
completed to reassess the monthly service and SDCs (both City and King County portions). Updates will coincide with 6-year CIP
updates.
37 The City will track the cost of claims as a metric. The City will create a baseline against which to evaluate future improvements.
38 The City will track schedule and budget accuracy and performance in CIP implementation.
Business practice
42
The City will monitor the frequency and causes of any service disruptions and develop programmatic methods for reducing the
number of disruptions (e.g., backups). The City will investigate all customer service calls within 24 hours and record results in the
computerized maintenance management system (CMMS). The City will develop an M&O plan to set goals for minimizing
blockages, backups, response time, etc.
43
The City will maintain an asset criticality database to be used in prioritizing asset maintenance and R&R. The existing criticality
database will be refined to include more asset age and material information, and will be validated using the results of M&O
inspections. The database will transition from a spreadsheet-based process to an internal process within the City’s CMMS.
44 The City will perform condition assessments of critical assets. The City will develop and implement a condition assessment
schedule for all critical assets.
City of Auburn Comprehensive Sewer Plan Executive Summary
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Table ES-1. Utility Level of Service
Item* Policy, standard, or guideline statement
45
The City will assign industry standard design lives for sewage assets. The actual physical assessment will be compared to the
theoretical design life to determine the optimal economic life. The City will attempt to repair or replace system assets before they
exceed their economic life. The number of high-criticality assets beyond their economic life will be minimized.
46
The City will conduct maintenance activities at a level that is consistent with optimizing system reliability, asset economic life, and
system performance. The City will develop schedules for maintenance of wastewater collection and conveyance assets and link its
implementation to system performance; e.g., record instances of missed maintenance and identify inadequate performance
related to maintenance (grease and roots blockages) including missed scheduled maintenance.
47
The City will maintain a level of reliability for pump stations provided by redundancy of critical mechanical and electrical
components. The City will provide backup power generators or dual power feeds and provide a minimum of two pumps at each City
pump station.
48
The City will implement the use of the National Association of Sewer Service Companies (NASSCO) Pipeline Assessment and
Certification Program (PACP) for inspection of all pipelines, Lateral Assessment and Certification Program (LACP) for inspection of
all laterals, and Manhole Assessment and Certification Program (MACP) for inspection of all manholes. The City will minimize the
number of assets with condition grades of 4 and 5.
* Item numbers refer to the policy item number presented in Table 3-1 in Section 3.4.
ES.2 Evaluation of the Sewer Utility
In order to develop a plan for future improvements to the Utility, the existing collection system was
evaluated. This included hydraulic modeling and a review of M&O practices, which are described
below:
• Hydraulic modeling: The existing hydraulic model developed in the 2009 plan was recalibrated
with King County flow monitoring data. The hydraulic capacity analysis of the City’s sewer
conveyance system assessed the capacity for current and projected wastewater flows. The
analysis also provided the basis for identifying improvements that may be necessary for the City
to provide the adopted LOS. The hydraulic model indicated that, based on current planning and
growth assumptions, there are no capacity-related issues for both current and future conditions.
• Maintenance and operation: The City provided information on its M&O activities to include
ongoing maintenance activities, the number of staff required to undertake the activity, and
frequency of activities. Current staffing levels were compared to anticipated staffing levels
required to meet the City’s desired operation goals listed in Chapter 6. The results of this
analysis indicate that, to meet these goals, two additional M&O staff are required and the
creation of a new position is recommended to facilitate computerized maintenance
management system (CMMS) integration across all three service utilities (Sewer, Water,
Drainage).
ES.3 Implementation Plan
The implementation plan brings together information from the preceding chapters to form a work
plan of future activities for the Utility. The implementation plan consists of the 6-year and 20-year
CIP, recommendations including monitoring and data collection, and recommendations for using
asset management strategies to improve Utility maintenance and operations with an outlook on
long-term sustainability.
ES.3.1 6-Year and 20-Year CIP
The CIP projects consist primarily of ongoing and programmatic capital improvements. Ongoing
projects include projects identified through previous studies. The City has previously allocated
funding to each of these projects, which are currently in various stages of execution. These projects
Executive Summary City of Auburn Comprehensive Sewer Plan
ES-4
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must continue to receive funding under the CIP until completion and have been included in this Plan
to provide a complete picture of the program. Programmatic projects are included in the CIP to
provide funding for maintaining and/or improving the LOS. These projects do not address a specific
problem, but allocate budget for addressing LOS goals.
The results of the system evaluation indicated very few new projects to be added to the 6-year CIP.
The system hydraulic analysis indicated no need for capacity-related capital projects.
Table ES-2 lists nine capital improvement projects included in this Plan and lays out annual
expenditures for the 6-year and 20-year CIP time frames.
City of Auburn Comprehensive Sewer Plan Executive Summary
ES-5
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Table ES-2. Annual CIP Project Cost Summary
Project
number Project name Priority 2016 2017 2018 2019 2020 2021 2022–35 Project Cost
CIP
allocations
(repair/
replacement)
CIP
allocations
(upgrade/
expansion)
1
Sanitary Sewer Repair
and
Replacement/System
Improvements
1 $1,873,000 $300,000 $1,500,000 $300,000 $1,500,000 $300,000 $12,600,000 $18,373,000 100% 0%
2 Street Utility
Improvements 1 $200,000 $200,000 $200,000 $200,000 $200,000 $200,000 $2,800,000 $4,000,000 100% 0%
3 Vactor Decant Facility 1 $150,000 $0 $0 $0 $0 $0 $0 $150,000 0% 100%
4
Sewer Pump Station
Replacement/
Improvement 1 $0 $141,000 $500,000 $168,000 $900,000 $141,000 $2,850,000 $4,700,000 100% 20%
5 Siphon Assessment 1 $0 $524,000 $0 $0 $0 $0 $524,000 $1,048,000 100% 0%
6 Pump Station Condition
Assessment 1 $187,000 $0 $0 $0 $0 $0 $187,000 $374,000 100% 0%
7 Manhole Ring and
Cover Replacement 2 $80,000 $80,000 $80,000 $80,000 $80,000 $80,000 $1,120,000 $1,600,000 100% 0%
8 Cleaning and Inspection
of Large-Diameter Pipe 2 $0 $400,000 $0 $0 $0 $0 $400,000 $800,000 100% 0%
9 Inflow and Infiltration
Study 3 $0 $135,200 $135,200 $135,200 $135,200 $135,200 $0 $676,000 100% 0%
10 Plan Update 1 $0 $0 $0 $0 $350,000 $0 $700,000 $1,050,000 50% 50%
Total cost for priority 1 projects $2,410,000 $1,165,000 $2,200,000 $668,000 $2,950,000 $641,000 $19,661,000 $29,695,000
Total cost for priority 2 projects $80,000 $480,000 $80,000 $80,000 $80,000 $80,000 $1,520,000 $2,400,000
Total cost for priority 3 projects $0 $135,200 $135,200 $135,200 $135,200 $135,200 $0 $676,000
Total CIP cost $2,490,000 $1,780,200 $2,415,200 $883,200 $3,165,200 $856,200 $21,181,000 $32,771,000
Executive Summary City of Auburn Comprehensive Sewer Plan
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ES.3.2 Monitoring
The current and projected future levels of I/I within the City’s collection system do not appear to
cause capacity-related issues. However, high I/I can be indicative of either deteriorating pipe
condition or storm drainage connections to the sewer system so, to be proactive, it is recommended
that the City initiate additional flow monitoring that can be used during the next Plan update to
further assess I/I and add confidence to the hydraulic model.
ES.3.3 Asset Management and Maintenance and Operations
The following additional recommendations were made for activities that will support asset
management and ongoing M&O:
• Continue system inventory: Asset management practices and M&O activities can best be utilized
with a completed inventory of assets owned and maintained by the City. Many of the City’s
assets are currently included in Cartegraph, its CMMS, but not all assets are currently included
and some assets are missing important identifying information (such as age and material of
construction). Completing the asset inventory will help the City continue to best apply its M&O
resources.
• Migrate the economic life model to the CMMS: The economic life model created as part of the
2009 plan should be implemented with the CMMS to facilitate use and most up-to-date model
accuracy.
• Optimize M&O program: Optimizing M&O activities through an asset management-based
program will lead to increased effectiveness in prioritizing M&O resources and managing risk,
public perception, regulatory compliance, and costs to the Utility.
• Discharge quality control: The City should continue its efforts to minimize the impact of harmful
components in the sewage discharged to the City’s collection system. Specifically, the fats, oils,
and grease (FOG) reduction program, industrial waste permitting, and public education programs
support the collection system’s ability to convey and pump sewage effectively and the County
treatment facility’s ability to protect the environment.
• Hazard planning: The City should assess vulnerability of the sewer collection system to examine
the potential for natural disasters such as flood, erosion, earthquake, or volcanic activity to
cause system failures. The associated probabilities of failure should be weighed with the
consequences of failure to determine if action is necessary and to identify appropriate mitigation
measures.
• Maintenance issues: Three known problem sites did not rise to the level of a CIP project based
on currently available information. It is recommended that the City investigate these known M&O
issues. The issues include odor issues near the 8th Street siphon and access issues with sewers
crossing freeways and those within easements on private property.
A timeline was developed to illustrate how CIP and monitoring activities in the implementation plan
fit together within 6-year and 20-year time frames. This timeline is presented on Figure ES-1.
City of Auburn Comprehensive Sewer Plan Executive Summary
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Project
number Project name 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
6-year CIP 7–20-year CIP
1 Sanitary Sewer Repair &
Replacement/System Improvements
2 Street Utility Improvements
3 Vactor Decant Study
4 Sewer Pump Station
Replacement/Improvement
5 Siphon Assessment
6 Pump Station Condition Assessment
7 MH Ring and Cover Replacement
8 Cleaning and Inspection of Large-
Diameter Pipe
9 Inflow and Infiltration Study
10 Plan Update
Figure ES-1. Implementation schedule
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Chapter 1
Introduction
This Comprehensive Sewer Plan Update (Plan) for the City of Auburn, Washington (City) is an update
to the previous plan, prepared in 2009. This plan should be considered a General Sewer plan under
authority of Washington Administrative Code (WAC) Section 173-250-050. Within this document,
Comprehensive Sewer Plan and General Sewer Plan should be considered the same. This Plan
reflects changes in existing and projected land use and population since the previous plan, as well
as sewer capital projects that have been constructed. In addition, since the previous plan, King
County has performed extensive flow monitoring of the City’s collection system that, along with
updated asset information, provides valuable information for updating the hydrologic and hydraulic
(H&H) model used for assessing system capacity.
This Plan contains time frames that are the intended framework for future funding decisions and
within which future actions and decisions are intended to occur. However, these time frames are
estimates and, depending on factors involved in the processing of applications and project work and
availability of funding, the timing may change from the included time frames. The framework does
not represent actual commitments by the City, which may depend on resources available.
This Plan meets the requirements of the Washington State Department of Ecology (Ecology) as set
forth in WAC Section 173-240-050. The Plan was submitted to Ecology; the Washington State
Department of Health (DOH); King and Pierce counties; the cities of Algona, Bonney Lake, Kent, and
Pacific; Lakehaven Utility District (LUD); Soos Creek Water and Sewer District (SCWSD); and the
Muckleshoot Indian Tribe (MIT). Relevant correspondence with these agencies related to this Plan is
included in Appendix A.
1.1 Purpose and Objectives
The purpose of the Plan is to guide the City with respect to future activities and improvements for the
Sanitary Sewer Utility (Utility). To fulfill this stated purpose, the following objectives were achieved:
• evaluate environmental, social, and regulatory drivers to develop level-of-service (LOS) goals for
capital facility infrastructure development, operation, maintenance, and other key elements of
Utility management
• update the comprehensive sanitary sewer system inventory, based on the City’s geographic
information system (GIS), that incorporates currently available infrastructure data into a digital
database that can be directly linked with the hydraulic model used for analyzing the system
• perform hydraulic modeling analysis to evaluate system capacity
• develop a plan for sewer service extensions, including where extensions will occur and how the
City will serve these areas
• document the City’s existing Maintenance and Operation (M&O) program, and evaluate existing
Utility staffing
• complete a financial analysis of the Utility, including a projection of cost to provide sewer service
and development of a funding strategy for the identified LOS goals
• develop a capital improvement program (CIP) by sustainably meeting required customer service
levels, effectively managing risks, and minimizing the City’s costs of sewer asset ownership
Chapter 1 City of Auburn Comprehensive Sewer Plan
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• prioritize capital improvement projects to accommodate both 6- and 20-year funding frameworks
1.2 Document Organization
This Plan is organized to focus on the actions that the Utility will take while implementing Plan
recommendations. Supporting documentation and background information is included in
appendices where appropriate. The Plan is organized into the following chapters:
Chapter 1 Introduction: explains the need for updating previous sewer planning documentation,
and outlines specific objectives of the Comprehensive Sewer Plan Update
Chapter 2 Background: provides background information regarding the Utility and sanitary sewer
service area (SSSA)
Chapter 3 Wastewater System Policies: specifies the Utility policies and LOS goals used to develop
capital improvements and future M&O activities
Chapter 4 Description of Existing System: describes the existing conditions of the City’s sanitary
sewer system
Chapter 5 Wastewater System Analysis: presents methodologies used to evaluate system capacity
and future sewer extensions
Chapter 6 Recommended Plan: describes recommended capital improvement projects including
cost estimates
Chapter 7 Maintenance and Operations: provides an overview of the organization and common
procedures associated with the ongoing M&O program, and evaluates existing Utility
staffing needs based on established LOS goals
Chapter 8 Finance: develops a funding plan that optimizes use of rates, systems development
charges, and/or other service fees based on projected Utility spending requirements and
a review of funding sources and City financial policies
Chapter 9 Implementation Plan: prioritizes capital improvement projects and lays out a future work
plan
Appendix A Inter-local Agreements and Outside Agency Correspondence: provides copies of inter-
local agreements related with sanitary sewer conveyance and disposal
Appendix B Hydraulic Capacity Analysis: provides a detailed review of the hydraulic modeling
completed for near- and long-term modeling scenarios to identify areas of capacity
concern
Appendix C Pump Station Information: provides detailed information related to the pump stations
(pump sizes, wet well size, etc.)
Appendix D SEPA Compliance: provides a letter documenting the “Determination of Non-
Significance”
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Chapter 2
Background
This chapter includes background information related to the development of the City’s current
wastewater collection and conveyance system, including changes to the City’s Comprehensive Plan
(Comp Plan) policies that influence the design and operation of the system. Also included is a
description of the City SSSA along with information on adjacent sewer utilities, which will facilitate an
understanding of existing and potential opportunities for collaborative activities with other purveyors
to enhance system reliability or reduce costs. Changes to land use planning efforts affecting the City
SSSA are also discussed.
The city of Auburn vicinity is shown on Figure 2-1.
2.1 Previous Auburn Comprehensive Sewer Plans
The current wastewater planning effort supersedes previous plans prepared in 1968, 1982, 2001,
and 2009. This Plan builds upon concepts established in the four previous plans, modifying or
updating goals, policies, and analyses to account for present conditions.
2.2 City Comprehensive Plan
The City most recently revised its Comp Plan in June 2015. The City Comp Plan incorporates the
Comprehensive Sewer Plan by reference.
2.3 Sanitary Sewer Service Area
The City SSSA has not changed significantly since the 2009 Comprehensive Sewer Plan, which
proposed the extension of service to a small area of unincorporated King County located west of
Algona that abutted the existing SSSA. Service has now been extended to that area. The current
SSSA is shown on Figure 2-2.
As of June 2015, the City currently serves 12,723 single family residential customers within its SSSA.
In addition, non-residential customers equate to 18,504 Residential Customer Equivalents (RCEs)
based on total water consumption records for non-residential connections. The City tracks total RCEs
and reports to the County quarterly.
The City coordinates service at the boundary of its SSSA with nearby sewer utilities. When the City’s
SSSA extends beyond current corporate limits, a franchise is required by the City of Auburn to own,
maintain, and manage the wastewater facilities within King and Pierce counties’ rights-of-way. This
coordination with other utilities and King and Pierce counties is discussed in Section 2.5.
2.4 Existing Land Use Plans
Various land use plans govern development with the City of Auburn SSSA; these plans are described
in the following sections.
2.4.1 King County Comprehensive Plan
Urban unincorporated areas of the City’s SSSA are subject to the King County Comprehensive Plan,
as most recently updated and adopted in November 2013. This section describes changes in the
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King County document affecting policy direction for functional plans, such as this City of Auburn
Comprehensive Sewer Plan Update.
In the updated 2013 King County Comprehensive Plan, policy F-255 states:
In the Urban Growth Area, all new development shall be served by public sewers unless:
a. Application of this policy to a proposal for a single-family residence on an individual lot
would deny all reasonable use of the property; or
b. Sewer service is not available for a proposed short subdivision of urban property in a timely
or reasonable manner as determined by the Utility Technical Review Committee. These on-
site systems shall be managed by one of the following entities, in order of preference:
1. The sewer utility whose service area encompasses the proposed short subdivision; or
2. The provider most likely to serve the area; or;
3. an Onsite Sewage System Maintainer certified by the Seattle-King County Department of
Health.
The onsite system shall meet all state and county approval requirements. The approved short
subdivision shall indicate how additional lots to satisfy the minimum density requirement of the
zoning will be located on the subject property in case sewers become available in the future. There
shall be no further subdivision of lots created under this policy unless served by public sewers.
In conjunction with policy F-255, policy F-256 states:
In the Urban Growth Area, King County and sewer utilities should jointly prioritize the replacement
of on-site systems that serve existing development with public sewers, based on the risk of
potential failure. King County and sewer utilities should analyze public funding options for such
conversion and should prepare conversion plans that will enable quick and cost-effective local
response to health and pollution problems that may occur when many on-site systems fail in an
area.
Chapter 5 discusses potential sewer extensions within currently unsewered areas. The City’s SSSA
currently includes two areas of unincorporated King County, as shown on Figure 2-2.
2.4.2 King County Regional Wastewater Services Plan
In 2007, King County adopted a revised Regional Wastewater Services Plan (RWSP), which outlines
proposed wastewater conveyance improvements. Improvements that impact the City of Auburn
collection and conveyance system include the following:
• Stuck River Trunk: new gravity pipe constructed to convey flow away from the M Street Trunk to
the Auburn West Interceptor
• Pacific Pump Station discharge: new pipe to convey flow north from the Pacific Pump Station to
the Auburn West Interceptor
• Auburn West Interceptor Parallel: new gravity pipe to replace or parallel an existing portion of the
Auburn West Interceptor between 15th Street SW and West Main Street
The Stuck River Trunk was completed in 2013. The Pacific Pump Station discharge and Auburn West
Interceptor Parallel are currently planned for construction in 2016.
In conjunction with the RWSP, the City participated in an inflow and infiltration (I/I) study as a
component sewer agency of King County. I/I is discussed in Section 4.4.
The County is in the process of updating the Conveyance System Improvements Program based on
decennial flow monitoring data and updated land use and population projections.
Algona
Pacific
Bonney
Lake
Kent
Federal Way
Sumner
COMPREHENSIVE SEWER PLAN
1 inch = 16,667 feet
October 2015
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Area of Kent Served by Auburn
Area of Pierce County Served by Auburn
Area of Pacific Served by Auburn
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Other Sewer Utilities within City of Auburn
City of Algona
Soos Creek Water and Sewer District
City of Kent
Lakehaven Utility District
Auburn City Boundary
County lineAdjacent Cities
Algona
Kent
Pacific
Sumner
Muckleshoot Indian
Reservation
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2.4.3 City of Auburn Water Resources Protection Report
As identified in the City’s 2009 Sewer Plan, coordination with the Water Utility will be necessary in
the future, as many of the City’s unsewered areas lie within the Water Resource Protection Areas
identified in the Water Resources Protection Report completed in 2000. In particular, planning for
future wastewater infrastructure could include the importance of removing potential contamination
(i.e., onsite sewer systems) from the Water Resource Protection Areas, based on coordination with
the Water Utility.
2.5 Neighboring Sewer Utilities
The communities that surround the city of Auburn administer their own wastewater conveyance and
collection systems. The following sections describe these systems and discuss interlocal agreements
between the City and these communities that establish SSSA boundaries and other conditions of
service. Neighboring sewer utilities are identified in Figure 2-2.
2.5.1 Soos Creek Water and Sewer District and City of Kent
In the northeast corner of the city, within the Lea Hill sewer basin (as shown on Figure 4-1), are small
areas served by the SCWSD and the City of Kent. In 2001, prior to annexation, the City of Auburn
executed interlocal agreements with SCWSD and Kent establishing sanitary sewer service area
boundaries. The agreements enable SCWSD and Kent to provide the most efficient method of
sanitary sewer service to this portion of the city while ensuring that the City’s development standards
are maintained. Copies of these agreements are included in Appendix A.
2.5.2 City of Pacific
An interlocal agreement establishing sanitary sewer service area boundaries between the cities of
Auburn and Pacific was executed in 2008. This agreement allows Auburn to provide sanitary sewer
service to property located on the eastern portion of Pacific’s municipal boundary, which lies in the
vicinity of Auburn’s wastewater infrastructure. The agreement recognizes that Auburn has sufficient
wastewater conveyance capacity to support the SSSA with maximum efficiency in the use of existing
and future facilities, together with orderly and efficient sanitary sewer planning. A copy of this
agreement is included in Appendix A.
2.5.3 Muckleshoot Indian Tribe Reservation
The MIT reservation is located within and to the southeast of Auburn city limits, as shown in Figure 2-
2. In 1997, the MIT, Indian Health Service, and City of Auburn entered into an agreement for the City
to provide wastewater service to the MIT property located outside city limits, outside the potential
annexation area (PAA), and outside the Urban Growth Area. An additional agreement, signed in
2004, outlined improvements to the conveyance system from the south end of the city on Auburn
Way South to the connection to King County’s M Street Trunk. Two outcomes of that agreement were
that (1) the MIT become a component agency of the King County Wastewater Treatment Division,
which officially occurred in July 2004, and (2) the MIT would own a portion of the capacity within the
Auburn Way South sewer line for the conveyance of sewage to King County. Lands owned by the MIT
within the City SSSA are billed as ordinary ratepayers. Development of lands within the MIT
reservation must be in accordance with the agreement approved under Resolution 4902. MIT-
related agreements are included in Appendix A.
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2.5.4 Lakehaven Utility District
In 2004, an interlocal agreement was established between LUD and the City of Auburn delineating a
mutual sewer service area boundary within a portion of the West Hill Service Area, an area recently
annexed by the City. It was determined that LUD should continue to provide sewer service to this
area in an efficient, cost-effective way.
An amendment to this agreement was established in 2005, transferring sewer service from LUD to
the City for the area known as Jovita Heights-West Hill. Copies of both LUD agreements are included
in Appendix A.
2.5.5 City of Algona
The city of Algona borders the city of Auburn to the southwest. In 2003, the cities of Algona and
Auburn executed an interlocal agreement establishing sanitary sewer service area boundaries. The
agreement allows Algona to provide sewer service to a small area in southwest Auburn, within the
city limits and adjacent to Algona. Sewer service by Algona provides efficiency in the use of existing
and future facilities. A copy of the Algona agreement is included in Appendix A.
2.5.6 City of Bonney Lake
An addendum to a 1998 interlocal agreement establishing sanitary sewer service area boundaries
between the cities of Bonney Lake and Auburn to roughly coincide with Auburn’s PAA boundaries was
executed in February 2005. The addendum added a single parcel to the City SSSA because the
parcel was partially located in both Auburn’s and Bonney Lake’s service areas as a result of the
previous agreement.
In April 2005, an interlocal agreement was established for Auburn to provide sanitary sewer service
to a parcel within Bonney Lake’s SSSA (and designated within Pierce County’s Urban Growth Area).
The maximum efficiency in the use of existing and future facilities is achieved by having Auburn
provide sewer service to this area within Bonney Lake. A subsequent agreement, executed in August
2005, allows for Bonney Lake to serve the parcel in question once a sewer franchise with Pierce
County has been secured for the area of Pierce County in which this parcel is located. Copies of both
Bonney Lake agreements are included in Appendix A.
2.5.7 King County
In 2002, the City of Auburn was granted a sanitary sewer franchise from King County to operate,
maintain, repair, and construct sewer mains, service lines, and appurtenances in, over, along, and
under County roads and rights-of-way in areas that at that time were located within unincorporated
areas of King County. The legal descriptions of the areas covered by that agreement were updated
through an amendment approved in January 2013. Copies of the agreement and amendment
(Resolution 5027) are included in Appendix A.
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Chapter 3
Wastewater System Policies
This chapter presents policies and standards that guide the operation and development of the City’s
wastewater collection and conveyance system. The policies and standards are derived from the
City’s Comp Plan, the Auburn City Code (ACC), and the 2009 Comprehensive Sewer Plan.
3.1 Sewer Comprehensive Plan Policies, Standards, and Guidelines
This Plan presents a number of policies or standards related to system development, maintenance,
funding, and generally how the Utility should operate. Table 3-1 organizes these various policies or
standards within topics related to service area, planning consideration, design standards, protection
of the environment and public health, customer satisfaction, Utility financing, wastewater quality,
business practice, and system performance and reliability. Taken together with the City
Comprehensive Plan and ACC, these policies define limits and outline how the wastewater collection
system shall be operated and maintained.
3.2 City Comprehensive Plan and Auburn City Code Goals and
Policies
The City Comp Plan is the City’s growth management plan and contains policies for protecting critical
areas and natural resource lands, designating urban growth areas, preparing comprehensive utility
plans, and implementing them through capital investments and development regulations. Therefore,
the Comp Plan provides a framework of policies for development, expansion, and maintenance of
the Utility.
The ACC is a collection of all the regulatory and penal ordinances and certain administrative
ordinances of the City. Title 13 of the ACC, Water, Sewers, and Public Utilities, contains the
ordinances most relevant to how the Utility operates.
It is an overarching policy that the Utility will comply and follow the City Comprehensive Plan and
ACC. References to the ACC are included in Table 3-1 where applicable.
3.3 Sanitary Sewer Level of Service
Wastewater utilities have begun to identify and articulate LOSs that define both the public service
they provide and a measurable representation of that service. By defining service in a quantifiable
way, the Utility is better able to determine whether it is meeting its own minimum performance
standards and, conversely, determine whether reallocation of resources or additional funding may be
justified to improve performance. Some LOSs might even be set for internal functions for the same
reason of helping to prioritize spending by recognizing critical activities. Policies that reflect or help
determine the LOS are spread throughout the various parts of Table 3-1, and are annotated with
“LOS” under their item number.
3.4 Business Practices Policy
The City desires to employ recognized best business practices that result in efficient and cost-
effective operation of the Utility. The City shall identify the key business functions within the Utility
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(e.g., billing, permitting, asset management, and planning) and develop supporting best business
practices for each. The Utility will conduct a performance audit every 6 years in conjunction with its
capital projects planning cycle to evaluate how well best business practices are being implemented
and how effective they are.
The City understands that defining and implementing best business practices is a long-term effort
and will require a stepwise approach. Given that the Utility is made up largely of physical assets that
have the greatest value and deserve the greatest commitment to operate and maintain, the City
shall address the business practice of asset management first.
Asset management is a systematic approach to maintaining assets in good working order to
minimize future costs of maintaining and replacing them, especially to avoid costly deferred
maintenance. The best practices for asset management involve systematically basing choices on an
understanding of asset condition and performance, risks, and costs in the long term. Asset best
practices include:
• having knowledge about assets and costs (i.e., detailed inventories)
• maintaining desired LOSs confirmed by customers
• taking a life-cycle approach to asset management planning
• implementing the planned solutions to provide reliable, cost-effective service
The Utility shall begin implementing the above best practices during the next planning period and
report progress annually. Policy items related to business practice include items 41–48 in Table 3-1.
Table 3-1. Sewer Comprehensive Plan Policies
Item Policy, standard, or guideline statement Related Auburn
City Code
Service Area
1 The City of Auburn comprehensive planning includes the provision for future sewer service to all properties
located within its current city limits and potential annexation area.
2 The Utility will consider, but not encourage, providing sanitary sewer service to properties outside the SSSA.
Property owners outside the SSSA bear the burden of approaching adjacent sewer providers for service.
3 The Utility does not intend to extend sanitary sewer service to or through King County rural zoned property.
4
Development where sewer service is not readily available may be served by individual onsite systems if the
individual lots are suitable for onsite systems per the requirements and approval of King County or Pierce
County Department of Health.
ACC 13.20.060
13.20.080
13.20.090
Planning Considerations
5 Future land use patterns for the SSSA are expected to correspond to existing uses or current designations. 6
LOS The City will size the sewer collection system for peak wet weather flow rates that include I/I flows. Gravity
sewers will be sized to convey the once-per-20-year peak hour flow without surcharging.
7
LOS
The City will size pump stations and force mains for peak wet weather flow rates that include I/I flows. Pump
stations will be sized to convey the once per 5-year flow with one pump out of service and convey the once per
20-year flow with all pumps in service.
Design Standards
8
The City has the authority to set design standards. The technical criteria used by the City for the design and
construction of its sanitary sewer infrastructure are based on the most recent versions of the Ecology
publication Criteria for Sewage Works Design (CSWD) and Washington State Department of Transportation
(WSDOT)/American Public Works Association (APWA) Standard Specifications. The City’s modifications and
supplements to this criterion are found in the City’s Engineering Design Standards and Construction Standards.
ACC 13.20.270
9 It is the City’s policy to transport sewage by gravity as the most cost-effective method.
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Table 3-1. Sewer Comprehensive Plan Policies
Item Policy, standard, or guideline statement Related Auburn
City Code
10 If public pump stations are required, the City will give preference to the construction of fewer large pump
stations over a greater number of smaller pump stations.
11 The City prefers to serve all properties by gravity sewer. Pumped systems will be allowed only when it is not
feasible to install a total gravity system.
12
Non-gravity services (e.g., grinder pumps, low-pressure force mains, or other on-site pumping facilities) are
prohibited except in extenuating circumstances when service by gravity is infeasible. The cost of installation,
operation, and maintenance of a non-gravity system shall be borne by the property owner, community
association, developer, etc. The City will not install, own, or maintain (outside of emergencies) any part of a
non-gravity system. The property owner shall select the non-gravity system from a list of accepted pump
manufactures and models. Prior to approval to install a non-gravity system, the property owner shall grant site
access to the City for emergency repairs in circumstances where a prompt repair is necessary to reduce the risk
of overflow. (See related Policy #20)
ACC 13.20.500,
13.20.510
13
All work on side sewers shall be completed with City licensed side sewer contractors. Side sewer contractors
shall have adequate financial resources for posting all required bonds commensurate with the size and type of
work.
14 Properties will be required to connect to the public sewer system in accordance with requirements listed in the
ACC. ACC 13.20.060
15
Private sewer systems are allowed within the SSA as long as they are designed and operated per City standards,
including access, and not part of sewer extensions to other parcels. Multiple connections per parcel are
allowed.
ACC 13.20.500
Protection and Improvement of the Environment and Public Health
16
LOS
The City will comply with all federal, state, and local regulations in operation and maintenance of the City’s
wastewater collection and conveyance infrastructure.
17
LOS
The City will evaluate Utility activities to emphasize sustainability practices. City staff will identify specific areas
to measure sustainability. Examples could include weighing energy consumption impacts more heavily during
capital project development, selecting less impactful cleaning and maintenance products, and structuring
maintenance activities to minimize vehicle travel miles. While maintaining minimum flows for efficient
operation of the system, water conservation will be practiced whenever possible. City staff will benchmark
practices and log changes.
18
LOS
The City will support the use of reclaimed water technologies where economically feasible. City staff will
evaluate opportunities for reclaimed water use and support initiatives where the benefits outweigh costs.
19
LOS
The City shall pursue I/I reduction for the purposes of eliminating or reducing required capacity upgrades and
reducing maintenance costs (to include reducing wear and tear on pump stations) when determined to be cost-
effective.
20
To protect public health and the environment, the City will require a property owner to promptly repair any non-
gravity system failure. If the property owner fails to do so, the City will take such action as it deems necessary to
prevent or rectify an overflow, including but not limited to temporarily suspending occupancy of the premises or
repairing the non-gravity system at the property owner’s expense.
ACC 13.20.500
13.20.510
Customer Satisfaction
21
LOS
Utility service delivery. The City will create a baseline against which to evaluate future improvements and
comparing to an annual assessment of complaints/citizen reports. The City will communicate proactively with
the community and stakeholders regarding wastewater service improvements.
Utility Financing
ACC 13.20.044,
13.20.048,
13.20.410,
13.20.440
22 Capacity issues within the existing system created by future development should be funded by future
developers.
23 The Utility shall implement an adequate system of internal financial controls and shall adopt an annual budget.
24 The Utility shall remain a self-supported enterprise fund; however, grants and other alternative financing may be
sought and used.
Chapter 3 City of Auburn Comprehensive Sewer Plan
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Table 3-1. Sewer Comprehensive Plan Policies
Item Policy, standard, or guideline statement Related Auburn
City Code
25 The funding for the CIP shall be sustained at a level sufficient to maintain system integrity. 26 The Utility shall establish fees and charges to recover all Utility costs related to development. 27 Sewer rates shall be established at a level sufficient to pay expenses and maintain adequate reserves. 28 Sewer rates shall be evaluated as part of the budgeting process. 29 The sewer rate structure shall allocate costs fairly among different customer classes. 30 Rates charged shall be uniform for all Utility customers of the same class throughout the SSSA.
31 Rate assistance programs may be provided for qualified specific low-income seniors or totally or permanently
disabled citizens.
32
The Utility should maintain adequate reserves for operation and maintenance, capital improvement, and Sewer
revenue bond obligations in order to ensure that the Utility can provide continuous, reliable service and meet its
financial obligations under reasonably anticipated circumstances.
33
The City shall require new customers to substantially pay for the costs of improvements designed to
accommodate growth, while the costs to operate, maintain, repair, and improve the existing system capacity
are paid by all sewer system customers.
34 The City will reinvest in Utility capital assets in order to ensure that the integrity of the existing Utility plant and
equipment is maintained. This reinvestment is generally referred to as repair and replacement (R&R).
35
In addition to projects designed to maintain and replace existing facilities, the City shall seek to invest annually
in system improvements designed specifically to upgrade the system in order to meet State regulations and the
City’s standards and criteria. These improvements may include upgrades to the sanitary sewer supervisory
control and data acquisition (SCADA) and data management systems, and upgrades to increase safety for both
City personnel and the public, bring noncompliant infrastructure into compliance, and reduce environmental
impacts.
36
LOS
Appropriate rates and SDCs shall be assessed to fund the ongoing maintenance, operation, and capital
expenditures of the Utility, in accordance with the Comprehensive Wastewater Plan. Periodic (typically every 5
years) cost of service studies shall be completed to reassess the monthly service and SDCs (both City and King
County portions). Updates will coincide with 6-year CIP updates.
37
LOS
The City will track the cost of claims as a metric. The City will create a baseline against which to evaluate future
improvements.
38
LOS The City will track schedule and budget accuracy and performance in CIP implementation.
Wastewater Quality
39
The City, in cooperation with King County, shall seek to maximize compliance with limits established in the ACC
that designate prohibited discharges to the public sanitary sewer. Waters and wastes including, but not limited
to, industrial process chemicals; pharmaceuticals; grit; and fats, oils, and greases (FOG) are limited or
prohibited from discharge to the public sewer according to the code.
ACC 13.20.140,
13.20.156,
13.20.158,
13.20.160
40 The City will actively discourage discharge of “flushable” wipes and other non-dispersible products to the
wastewater collection system. ACC 13.20.140
Business Practice
41
The City will develop and implement system improvements, infrastructure renewal (repair, rehabilitation, or
replacement), and M&O programs for the wastewater system according to asset management principles that
address LOSs, address the triple bottom line (economic, social, and environmental benefits and costs),
minimize asset life-cycle costs, and incorporate risk management into decision making.
42
LOS
The City will monitor the frequency and causes of any service disruptions and develop programmatic methods
for reducing the number of disruptions (e.g., backups). The City will investigate all customer service calls within
24 hours and record results in the computerized maintenance management system (CMMS). The City will
develop an M&O plan to set goals for minimizing blockages, backups, response time, etc.
43
LOS
The City will maintain an asset criticality database to be used in prioritizing asset maintenance and R&R. The
existing criticality database will be refined to include more asset age and material information, and will be
validated using the results of M&O inspections. The database will transition from a spreadsheet-based process
to an integral process within the City’s CMMS.
City of Auburn Sewer Comprehensive Plan Chapter 3
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Table 3-1. Sewer Comprehensive Plan Policies
Item Policy, standard, or guideline statement Related Auburn
City Code
44
LOS
The City will perform condition assessments of critical assets. The City will develop and implement a condition
assessment schedule for all critical assets.
45
LOS
The City will assign industry standard design lives for sewage assets. The actual physical assessment will be
compared to the theoretical design life to determine the optimal economic life. The City will attempt to repair or
replace system assets before they exceed their economic life. The number of high-criticality assets beyond their
economic life will be minimized.
46
LOS
The City will conduct maintenance activities at a level that is consistent with optimizing system reliability, asset
economic life, and system performance. The City will develop schedules for maintenance of wastewater
collection and conveyance assets and link its implementation to system performance; e.g., record instances of
missed maintenance and identify inadequate performance related to maintenance (grease and roots
blockages) including missed scheduled maintenance.
47
LOS
The City will maintain a level of reliability for pump stations provided by redundancy of critical mechanical and
electrical components. The City will provide backup power generators or dual power feeds and provide a
minimum of two pumps at each City pump station.
48
LOS
The City will implement the use of the National Association of Sewer Service Companies (NASSCO) Pipeline
Assessment and Certification Program (PACP) for inspection of all pipelines, Lateral Assessment and
Certification Program (LACP) for inspection of all laterals, and Manhole Assessment and Certification Program
(MACP) for inspection of all manholes. The City will minimize the number of assets with condition grades of 4
and 5.
System Performance and Reliability
49 The City shall create, update on a routine basis, and use an emergency response plan for critical facilities.
50
The City may work on private property on private assets when the private asset is negatively impacting the public
system. If the condition requiring such work is the responsibility of the owner, the City shall seek to recover the
costs for the work.
ACC 13.20.182,
13.2.510
51
LOS
The City may replace or repair private side sewers as part of a City initiated project to reduce I/I of extraneous
water into the sanitary sewer system where shown to be cost-effective versus capacity improvements.
52
The City will monitor the frequency, location, and details of all odor-related complaints. At a minimum, the City
will respond, research the cause of, and propose control methods once three complaints per month at a site are
documented.
53
Adequate measures shall be taken to ensure system security. At a minimum, the City shall maintain security at
pump stations by using the SCADA system (motion detection, intrusion alarms) to alert City personnel when
unauthorized access is occurring.
54
The City encourages employee participation in workshops, seminars, and other education programs to improve
job skills. The City may pay fees and employees’ time for the required certification testing, as well as required
annual renewal fees if such certification is a job requirement.
4-1
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Chapter 4
Description of Existing System
This chapter describes the existing wastewater collection and conveyance system and SSSA. The City
provides wastewater collection service to city residences and businesses through a variety of
facilities including gravity sewers, pump stations, and force mains. The wastewater flow is conveyed
to the King County Regional Wastewater System for treatment and disposal. The City’s system
consists of 15 sewer pump stations 1, approximately 5,200 manholes, and approximately 200 miles
of sewers and force mains. The City’s system is intended to collect and convey only sanitary flow, but
the flow also includes rainfall-derived I/I. According to City staff, there are no known sanitary sewer
overflows (SSOs) in the system.
4.1 Overview
For purposes of discussion, the City’s wastewater collection system is divided geographically into five
major sewer basins. The descriptions of the five major sewer basins (Valley, West Hill, Lea Hill,
Auburn Way South, and South Hill) are presented below and shown on Figure 4-1.
4.1.1 Valley Sewer Basin
The Valley Sewer Basin is located on the valley floor and contains the oldest portions of the City’s
sewer collection system. Three primary King County trunk sewer lines (Stuck River Trunk Sewer, M
Street Trunk Sewer, and Auburn West Interceptor Sewer) convey flow from south to north along this
sewer basin, providing the backbone for service to Auburn. The Valley Sewer Basin receives flows
from the other four sewer basins and conveys these flows to the King County sewer trunk lines. The
topography of the valley is very flat with a minor incline, sloping down from the south end of Auburn
(elevation 109 feet) to the north end of Auburn (elevation 53 feet). Seven pump stations are located
within the Valley Sewer Basin to serve areas unable to reach the King County trunk lines by gravity.
The City provides service to two small areas of unincorporated King County, located within the sewer
basin. The Valley Sewer Basin is bounded by the Lea Hill and Auburn Way South sewer basins to the
east, the South Hill Sewer Basin and the cities of Algona and Pacific to the south, the West Hill Sewer
Basin to the west, and the city of Kent to the north.
4.1.2 West Hill Sewer Basin
The West Hill Sewer Basin is located on the West Hill above the valley floor. Flows from the West Hill
Basin are conveyed to two King County trunk lines—the Auburn West Valley Interceptor and the
Auburn Interceptor. One pump station, Peasley Ridge, serves a small area within the West Hill Sewer
Basin. The West Hill Sewer Basin is bounded by the Valley Sewer Basin to the east, city of Algona to
the south, LUD to the west, and city of Kent to the north.
The western boundary of the West Hill Sewer Basin, which is also the western boundary of the
service area, was established by interlocal agreements with LUD in 2004 and 2005 (see
Appendix A).
1 Utility staff also maintain five sewer pump stations owned by and serving other City agencies (see Chapter 7).
Chapter 4 City of Auburn Comprehensive Sewer Plan
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4.1.3 Lea Hill Sewer Basin
The Lea Hill Sewer Basin is the portion of the city located to the east of the Green River. Sewer flows
exit the basin into the Valley Sewer Basin by river crossings at the 8th Street Bridge or the Green
River Siphon (see Section 4.2.4). There is a significant unsewered area in the north portion of the
Lea Hill Sewer Basin. A portion of the city of Kent lies within this sewer basin, and is served by City
sewer infrastructure, including the new Verdana Pump Station. The northwest area of the sewer
basin is served by SCWSD and the City of Kent (see Figure 4-1).
The north and east boundaries of the Lea Hill Sewer Basin are defined by a 2001 interlocal
agreement with the City of Kent and by a 2006 interlocal agreement with the Soos Creek (see
Appendix A).
4.1.4 Auburn Way South Sewer Basin
The Auburn Way South Sewer Basin is located east of the Valley Sewer Basin along Auburn Way
South on the Enumclaw Plateau. It is geographically bounded by State Route 18 to the north and the
White River to the south. The southeast portion of the Auburn Way South Sewer Basin borders the
MIT reservation sewer service area. The City and the Muckleshoot Utility District (MUD) jointly own a
major trunk line that discharges to King County’s newly constructed Stuck River Trunk Line at the
northwest edge of the sewer basin.
4.1.5 South Hill Sewer Basin
The South Hill Sewer Basin is bounded by the White River to the north and east, city of Pacific to the
west, and city of Sumner and Pierce County to the south. The western half of the South Hill Sewer
Basin has been developed as a residential area. Although most of the major sewer infrastructure
serving the residential area is already in place, several significant developments are currently being
constructed. The eastern half (east of Kersey Way) of the sewer basin is currently developed as low-
density rural area and is unsewered. Three pump stations (Area 19, Terrace View, and North Tapps)
serve the southern extent of the sewer basin. All of the flow from the South Hill Sewer Basin is
conveyed to King County’s Lakeland Hills Pump Station, from where it is pumped to King County’s
Lakeland Hills Trunk sewer located in the Valley Sewer Basin.
4.2 Sanitary Sewer Facilities
The following sections provide information regarding the City’s wastewater facilities. Locations of the
pumping facilities, river crossings, King County trunk lines, and other key system elements are
shown in Figure 4-2. Ownership of interceptor and collection system pipelines is indicated on the
figure by line color. Figure 4-2 also shows the City’s potable water pumps, wells, and reservoirs. The
City of Auburn draws its potable water from deep aquifer wells located throughout the city. While no
sewage treatment facilities are located within the city, portions of the conveyance system are located
in the vicinity of some of those wells. Most of the sewer lines are located more than the 100 feet
from the wellheads as stipulated for new sewer works by Ecology’s Criteria for Sewage Works Design
(CSWD) (G2-1.5.3), two wellheads are located less than 100 feet from existing sanitary sewers, as
shown on Figure 4-2.
xxx
GreenRiver
LakeTapps
BigSoos C re e k
MillCreek
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Sumner
Kent
Area of Bonney Lake served
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WhiteRiver
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King County
textUnincorporated King County
Unincorporated
Pierce County
text
Area of Kent
served by Auburn
Sewer System
Area of Pacific servedby Auburn Sewer System
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 4-1SEWER SERVICE BASINS3,500 0 3,500 7,000
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Pierce County
L E G E N D
Sanitary Sewer Basins
Auburn Way South
Lea Hill
South Hill
Valley
West Hill
King County Collection System
Major Roads
Street
Area of Pacific Served by Auburn
Area of Bonney Lake Served by AuburnOther Sewer Utilities within City of Auburn
City of Algona
Soos Creek Water and Sewer District
City of Kent
Lakehaven Utility District
Auburn City Boundary
County line
Water
Streams
Streets
Political Boundaries
M StreetTrunk Sewer
Auburn
Interceptor
Auburn West ValleyInterceptor
Auburn West
Interceptor Sewer
Stuck RiverTrunk Sewer
Lakeland HillsTrunk Sewer
West HillSewer Basin
Lea HillSewer Basin
Auburn Way SouthSewer Basin
South Hill Sewer Basin
Valley SewerBasin
GreenRiver
LakeTapps
BigSoos C re e k
MillCreek
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Dogwood
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R Street
F Street
Auburn 40
Riverside8th Street
North Tapps
22nd Street
Auburn Jail
Terrace View
Rainier RidgePeasley Ridge
Lakeland Hills
Valley Meadows
Ellingson Road
Issac Evans Park
Auburn Golf Course
Auburn Justice Center
Auburn Valley Humane Society
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 4-2EXISTING WASTEWATERCONVEYANCE SYSTEM3,500 0 3,500 7,000
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King County
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L E G E N D
Auburn Sewers
Bonney Lake Sewers
King County Sewers
Kent Sewers
Lakehaven Sewers
Auburn/MIT Joint Sewers
MIT Sewers
Private Sewers
Auburn Pump Station
King County Pump Station
Private Pump Station
Water Pump Stations
Water Reservoirs
Water Wells/Springs
Potable Water Well Within 100 Feet of Sewers
Major Roads
Street
Area of Pacific served by Auburn
Area of Bonney Lake served by AuburnOther Sewer Utilities within City of Auburn
City of Algona
Soos Creek Water and Sewer District
City of Kent
Lakehaven Utility District
Auburn City Boundary
County line
Muckleshoot Indian
Reservation
Streams/Rivers/Ponds
Political Boundaries
West HillSewer Basin
Lea HillSewer Basin
Auburn Way SouthSewer Basin
South Hill Sewer Basin
Valley SewerBasin
River Crossing
River Crossing
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4.2.1 Critical Infrastructure
For planning purposes, the City considers all sewer pump stations, force mains, river crossings, and
major trunk lines (pipes greater than or equal to 12 inches in diameter) to be critical infrastructure.
Also, all gravity sewer lines serving the hospital, city hall, City maintenance facility, Justice Center,
and fire stations are considered critical. These critical assets are shown in Figure 4-3.
4.2.2 Pump Stations
Since preparation of the 2009 Comprehensive Sewer Plan, the City has constructed, replaced, or
decommissioned several sewer pump stations. Recently constructed or replaced pump stations
include Auburn 40 (new), Dogwood, Ellingson, and Verdana (new). Three decommissioned facilities
include the D Street, Rainier Shadows, and White Mountain Trails pump stations.
The City currently has 15 pump stations within its SSSA. The pump stations are listed in Table 4-1
along with their location and year of construction or most recent replacement. More detailed
information regarding the pump stations is provided in Appendix C.
Table 4-1. City of Auburn Sewer Pump Station Inventory
Pump station Year
constructed/replaced Cross streets Approximate address
South Hill Sewer Basin
Area 19 2006 Lake Tapps Pkwy. E & west of 72nd St. SE 800 71st Street SE
North Tapps 2007 Lake Tapps Pkwy. SE & west of 176th Ave. E 2610 Lake Tapps Pkwy. SE
Terrace View 2007 East Valley Hwy. E & north of Terrace View Dr. SE 6005 East Valley Highway
Valley Sewer Basin
Auburn 40 2010 42nd St NE & O Pl. NE 4159 O Pl. NE
Ellingson 2011 41st St. SE, East of A St. SE 40 41st St. SE
F Street 1980 F St. SE & 17th St. SE 1700 F St. SE
R Street 1977 R St. NE & 6th St. NE 600 R St. NE
Valley Meadows 1992 4th St. SE & V St. SE 2022 4th St. SE
8th Street 1974 J St. NE & 8th St. NE 900 8th St. NE
22nd Street 1967 22nd St. SE & Riverview Dr. 1950 22nd St. NE
Auburn Way South Sewer Basin
Dogwood 2010 Dogwood St. SE & 15th St. SE 1423 Dogwood St. SE
West Hill Sewer Basin
Peasley Ridge 2001 S. 320th St. & 53rd Ave. S 5225 S 320th St.
Lea Hill Sewer Basin
Rainier Ridge 1980 125th Pl. SE & south of SE 318th Way 31809 125th Pl. SE
Riverside 1981 8th St. NE & 104th Ave. SE 31902 104th Ave. SE
Verdana 2011 118th Ave SE & SE 296th Pl. 11807 SE 296th Place (Kent)
Chapter 4 City of Auburn Comprehensive Sewer Plan
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4.2.3 Gravity and Force Main Collection System
The City sewer collection system includes approximately 195 miles of gravity and 5 miles of force
main pipe. The collection system consists primarily of polyvinyl chloride (PVC) or concrete pipe with a
diameter of 8 inches. Older areas of the collection system consist of clay pipe, which the City has
been replacing with other material when repairs are required. The City is continually updating its
digital geographic and record-keeping systems to include pipeline information such as age, diameter,
and installation date. Figure 4-4 provides a visual representation (by overall system percentage) of
pipeline characteristics, including unknown and/or unrecorded data. The largest current data gap is
the installation date of collection system facilities. As part of the City’s asset management efforts,
City staff will verify collection system information during routine inspections.
Additional conveyance facilities, primarily owned by King County, are also located within the Auburn
SSSA. King County conveyance facilities are discussed in Section 4.3.
4.2.4 Side Sewer Laterals
The Utility is responsible for the maintenance and repair of the portion of side sewer laterals within
the right-of-way or public sewer easement.
4.2.5 River Crossings
The City of Auburn collection system contains two crossings of the Green River. The crossings are
located at the 8th Street NE bridge and near 26th Street NE, and are shown in Figure 4-2. Detailed
descriptions of each river crossing are provided below.
4.2.5.1 Green River Crossing (via 8th Street NE)
The first crossing of the Green River was constructed in 1965. The crossing consists of a cast-iron
pipe mounted on the 8th Street NE bridge. Because the bridge is at a higher elevation than the bank
on either side, the pipe does not have a positive downhill slope across the bridge and must rely on
upstream pressure developed in the line as it comes down Lea Hill to force the flow across the
bridge. For this reason, the pipe on the bridge and continuing up Lea Hill approximately 900 linear
feet, is constructed of 14-inch-diameter cast-iron pressure pipe. At the bottom of the hill, just
upstream of the bridge, a valve chamber houses a mechanically operated control valve. The valve
was designed to remain closed until pressure, as caused by the upstream pipe filling, opens the
valve, and releases the flow across the bridge. Flow within this sewer segment is sufficiently high to
maintain continuous scouring flow along the flat portion of the pipeline.
4.2.5.2 Green River Crossing (via Inverted Siphon at 26th Street NE)
The inverted siphon across the Green River near 26th Street NE was constructed in 1986 and
includes parallel 8- and 12-inch-diameter siphon pipelines. The 8-inch-diameter siphon is typically in
use. When increased flows occur, wastewater will be redirected to the 12-inch-diameter siphon. If
needed, both siphons are capable of operating together. The siphon facility includes a flushing
manhole, located in Isaac Evans Park.
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RIVERSIDE8TH STREET
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COMPREHENSIVE SEWER PLAN
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River Crossing
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L E G E N DCritical Facilities
Critical Service
Fire Station
Hospital
Pump Stations
Critical Sewers
County line
King County Sewers
Sewers
Major Roads
Street
City of Auburn Sewer Service Area
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City of Auburn Sewer Comprehensive Plan Chapter 4
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Figure 4-4. City of Auburn collection system summary statistics
0.9% 1.6%
70.7%
10.2%
8.1%
8.5%
Pipe Diameter
UNKNOWN
< 8 inches
8 inches
10 inches
12 inches
> 12 inches
NOT CURRENTLY
COMPILED IN
CMMS DATABASE
56.5%
1.5% 0.9%
3.1%
11.4%
19.5%
7.2%
Pipe Installation Date
UNKNOWN
1960s
1970s
1980s
1990s
2000s
2010s
NOT CURRENTLY
COMPILED IN
CMMS DATABASE
13.5%
1.5%
8.7%
1.4% 1.7%
73.2%
Pipe Material
UNKNOWN
CLAY
CONCRETE
DUCTILE IRON
HDPE
PVC
NOT CURRENTLY
COMPILED IN
CMMS DATABASE
Chapter 4 City of Auburn Comprehensive Sewer Plan
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4.3 King County Conveyance
The King County wastewater conveyance facilities serving the City include the Auburn Interceptor,
Auburn West Valley Interceptor, Auburn West Interceptor, M Street Trunk sewer, the newly
constructed Stuck River Trunk sewer, the Lakeland Hills Trunk sewer, and the Lakeland Hills Pump
Station. As shown on Figure 4-2, the King County facilities convey wastewater from the south to the
north, collecting flow from the Auburn SSSA. The Auburn West Valley Interceptor begins in Algona
and flows through the West Hills sewer basin. The Lakeland Hills Trunk sewer and Auburn West
Interceptor carries flow from the Lakeland Hills Pump Station north. The M Street Trunk sewer lies
mainly on the eastern side of the Valley basin. The Stuck River Trunk sewer extends from the south
end of the M Street Trunk sewer in a westerly direction, where it intersects the Lakeland Hills Trunk
sewer. All flows are conveyed to the King County South Treatment Plant in Renton, Washington.
King County recently proposed several modifications to its conveyance system, to be completed in
two phases, to address projected capacity limitations. Phase A consisted of constructing a new
sewer, called the Stuck River Trunk sewer, to convey wastewater flow from the south end of the
existing M Street Trunk sewer and route it west to the Lakeland Hills Trunk sewer. Phase A
construction was completed in 2013. Phase B is currently under design and is planned for
completion in 2016. Phase B consists of constructing a new sewer, called the Auburn West
Interceptor Parallel, which will run parallel to the existing King County Auburn West Interceptor
sewer. This pipe will run north from the intersection of Perimeter Road and 15th Street SW, cross
under State Route 18, and connect to the existing Auburn West Interceptor at West Main Street and
Clay Street in Auburn. Phase B also includes a new pipeline to carry wastewater north from the city of
Pacific to Auburn. The sewer will run from King County’s Pacific Pump Station to the new Auburn
West Interceptor Parallel.
4.4 Infiltration and Inflow
King County has been conducting studies of existing I/I conditions in various local sewer agencies,
including the city of Auburn, since 2000 as part of a Regional I/I Control program within the overall
RWSP. The studies (see www.kingcounty.gov/environment/wastewater/II/Resources/Reports.aspx)
include flow monitoring, modeling, construction of pilot I/I reduction projects, and follow-up analyses
to determine the cost-effectiveness of various approaches. As a result of the study findings, King
County plans to undertake several I/I reduction projects; however, no capital projects are currently
planned for construction in Auburn.
The I/I within the City’s SSSA was assessed as part of the modeling for the RWSP. The simulated I/I
flows for some model basins exceeded the 1,100 gallons per acre day (gpad) King County standard 2,
as discussed in Chapter 5. The City will address I/I through the evaluation of its construction
standards, annual repair and replacement (R&R) projects, and the development of projects to
address large sources of I/I identified by maintenance staff. Furthermore, the City will include a
project as part of the CIP (see Chapters 6 and 9) that will monitor flows within the collection system
over the next 5 years. The data collected will be used for future system capacity modeling and I/I
assessment.
4.5 Industrial Waste Discharges
As part of its conveyance service, the City accepts industrial waste from permitted industrial waste
dischargers. King County staff manage the industrial waste program, including permitting,
2 King County Code (KCC), Section 28.84.050
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inspection, record-keeping, and enforcement. At present, the City does not project future industrial
expansion; however, a policy is in place to collaborate with King County regarding permitting
processes if expansion should occur. Table 4-2 below identifies the current industrial waste
dischargers within the City SSSA. For updated Industrial Waste Discharge Permit information, contact
King County’s Industrial Waste Program by phone (206.477.5300) or E-mail
(Info.KCIW@kingcounty.gov).
Table 4-2. City of Auburn Industrial Waste Discharge Permits
Company name Business type Address Permit type
Accurate Industries Metal Finishing: CFR 433 233 D Street NW Permit
Aero Controls, Inc. Metal Finishing: CFR 433 1610 20th Street NW Minor Discharge Authorization
American Powder Coating Metal Fabrication 3802 B Street NW Letter of Authorization
Auburn Dairy Products Food Processing: Dairy 702 West Main Street Major Discharge Authorization
Auburn School District – Riverside High
Scholl Ballfield Construction Project Construction Dewatering 501 Oravetz Road SE Letter of Authorization
Auburn, City of – 30th Street NE Storm
Drainage Construction Project Construction Dewatering 30th Street NE and Auburn Way Minor Discharge Authorization
Auburn, City of: Decant Facility Decant Station 1305 C Street SW Major Discharge Authorization
Black Oxide, LLC Metal Finishing: CFR 433 131 30th Street NE, Suite 25 Permit
Boeing Commercial Airplane: Auburn Metal Finishing: CFR 433 700 15th Street SW Permit
ChemStation General Type 3104 C Street NE, Suite 202 Letter of Authorization
Formula Corp.: Auburn General Type 4432 C Street NE Major Discharge Authorization
Hexacomb Corp. General Type 2820 B Street NW, Suite 111 Letter of Authorization
Hospital Central Services Association, Inc. Laundry - Linen 1600 M Street NW Major Discharge Authorization
Merrill Gardens at Auburn Construction
Project Construction Dewatering South Division Street Letter of Authorization
Oldcastle Precast Cement/Readymix 2808 A Street SE Major Discharge Authorization
Ply Gem Pacific Windows Corporation Manufacturing: Misc 5001 D Street NW Minor Discharge Authorization
Safeway, Inc.: Auburn Distribution Center Vehicle Washing 3520 Pacific Avenue South Letter of Authorization
Skills, Inc.: Auburn Facility Metal Finishing: CFR 433 715 30th Street NE Permit
TMX Aerospace General Type 5002 D Street NW, Suite 104 Major Discharge Authorization
Tri-Way Industries, Inc. (Auburn) Metal Finishing: CFR 433 506 44th Street NW Permit
Waste Management – South Sound Container Washing 701 2nd Street NW Minor Discharge Authorization
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City maintenance staff manage commercial dischargers in accordance with ACC Chapter 13.22.
Maintenance activities related to commercial pretreatment facilities, specifically the City’s Fats, Oils,
and Grease (FOG) Reduction Program, are discussed in Section 7.3.
4.6 Water Reclamation and Reuse
Reclaimed water is wastewater that has been treated to a level at which it can be used safely and
effectively for beneficial, non-drinking water purposes. The City does not currently use reclaimed
water because there are no nearby sources or transmission pipelines for reclaimed water, and there
are no users within the SSSA with significant volume needs that would drive implementation of reuse
projects.
This section summarizes the regulatory framework surrounding the generation and use of reclaimed
water, potential reclaimed water sources and users, and City planning for near-term reclaimed water
use within the City SSSA.
4.6.1 Regulatory Framework
The state has identified reclaimed water as an important water resource management strategy that
can offer benefits related to potable water supply, wastewater management, and environmental
enhancement. State law supports the beneficial reuse of reclaimed water for consumptive
applications (such as irrigation, commercial and industrial process use, etc.) and non-consumptive
purposes (including groundwater recharge via surface percolation or direct injection, wetland
enhancement, and stream flow augmentation).
DOH and Ecology have developed standards that guide the planning and development of reclaimed
water projects and systems. These standards, summarized in the jointly published Water
Reclamation and Reuse Standards (September 1997), describe the allowable beneficial uses of
reclaimed water and the required levels of treatment appropriate for each use. The Standards
establish four classes of reclaimed water; A, B, C, and D. Class A reclaimed water represents the
highest level of treatment, referring to water that is oxidized, coagulated, filtered, and disinfected to
certain standards. Of all levels of reclaimed water, Class A is acceptable for the widest range of uses.
Additional clarification and guidance related to the design of reclaimed water facilities are provided
in Ecology’s CWSD (Ecology, 2008).
Ecology prepared draft reclaimed water regulations (WAC 173-219) to further define and provide
guidance for reclaimed water facilities and uses. The rule-making process began with legislation in
2006 that amended the Reclaimed Water Use Act, Revised Code of Washington (RCW) Chapter
90.46, and directed Ecology to coordinate with DOH, form a stakeholder Rule Advisory Committee,
and adopt a comprehensive rule for reclaimed water use by December 2010. The overall goal was to
develop a Reclaimed Water Program through rule, guidance, and statute that runs smoothly and
consistently while protecting public health and the environment. Several drafts of the proposed rule
were made available for review by stakeholders, and significant comments were submitted, but the
rule-making process was suspended by executive order before it could be completed. Ecology
reactivated the rulemaking process in June 2014 with estimated implementation of the adopted rule
in early 2016.
4.6.2 Potential Reclaimed Water Sources
This section identifies potential sources of reclaimed water in the vicinity of the City SSSA.
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4.6.2.1 King County
City of Auburn wastewater is treated at King County’s South Treatment Plant, located in Renton,
approximately 13 miles north of Auburn. Although South Plant does generate reclaimed water for
onsite uses and nearby irrigation and habitat restoration, there are no existing or planned
transmission lines south to the City of Auburn. The status of current King County reclaimed water
comprehensive planning is discussed in Section 4.6.3.
4.6.2.2 City of Sumner
The City of Sumner wastewater treatment plant is located approximately 8 miles south of the city of
Auburn. Sumner does not currently produce reclaimed water for offsite uses, but the City will
continue to monitor Sumner’s plans for reclaimed water use to determine if transmission of
reclaimed water from Sumner to the City of Auburn is feasible and cost-effective for potential users
within the City of Auburn SSSA.
4.6.2.3 Lakehaven Utility District
LUD owns and operates two wastewater treatment plants, the Lakota and Redondo facilities, located
approximately 7 miles to the west and northwest of the city of Auburn. LUD does not currently
produce reclaimed water, but has evaluated the feasibility of producing reclaimed water for
landscape irrigation and groundwater recharge. Because the Redondo facility site is limited with
respect to expansion area, reclaimed water improvements, if implemented, would likely occur at the
Lakota facility. The City will continue to monitor LUD planning efforts with respect to reclaimed water
production and reuse.
4.6.2.4 City of Auburn
Although the City of Auburn does not operate a centralized wastewater treatment plant, a smaller,
satellite reclaimed water production facility could feasibly be installed at one of the City’s pump
stations. A satellite facility could be used to capture wastewater flows from a specific basin, and then
generate reclaimed water for uses nearby. While a range of treatment approaches may be employed
at a satellite facility, many utilities are implementing membrane bioreactor (MBR) technology in
these types of applications, because of the small footprint required relative to other, more
conventional forms of wastewater treatment. Solids generated at the satellite facility would be
returned to the collection system and conveyed to King County’s South Treatment Plant.
4.6.3 Potential Reclaimed Water Users
Starting in 2009, King County began development of a Reclaimed Water Comprehensive Plan to
evaluate expansion of its existing reclaimed water program over a 30-year period. The City of Auburn
has supported the County’s planning process by providing non-potable water use data by specific
parcel. City staff and elected officials have also participated in reclaimed water workshops held at
key points in the County planning process. Although the Reclaimed Water Comprehensive Plan is not
complete, the County has identified and recommended policies to be further developed moving
forward. The County recommends optimizing existing reclaimed water infrastructure and
investments, with no further expansion of the reclaimed water program.
Figure 4-5, from King County’s Reclaimed Water Comprehensive Plan, presents the location of
potential reclaimed water users within Auburn city limits, color-coded by use. Most identified uses of
large volumes of water are for irrigation, which is seasonal use (approximately 4 months per year.
The industrial/commercial uses identified could use reclaimed water throughout the year, but none
of the identified users are currently a high-volume water user.
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4.6.4 Reclaimed Water Summary
The City of Auburn is not planning any specific capital improvements related to producing and/or
conveying reclaimed water for the following reasons:
• King County sources of reclaimed water are unlikely to be developed for use within the City SSSA
in the near term.
• The City currently has adequate water supply and the need for offsetting potable water demands
is low at this time.
• The capital costs related to design, construction, and permitting of a reclaimed water production
facility and conveyance system to serve identified uses is not justified by generally seasonal
demand and absence of financial benefit.
The City acknowledges the value that a reclaimed water program might offer in the future, especially
if a nearby reclaimed water source with associated conveyance piping is extended to the City’s SSSA.
The City will continue to monitor reclaimed water planning by nearby purveyors, the adequacy of the
City’s water rights to meet current and future potable water demand, and the industrial user base to
evaluate whether reclaimed water is a feasible and economically viable alternative. City staff will also
continue to participate in King County’s reclaimed water comprehensive planning process to
promote the City’s interests in County policies, criteria, and implementation strategies.
!
!
!!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!King County
Pierce County
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Auburn Super MallPIN: 2421049076
Auburn Game Farm ParkPIN: 2921059069
Carpinito FarmsPIN: 0000400001 0006800002 3122059019
Mosby Bros. Farm - AuburnPIN: 2121059145 2121059096
Game Farm Wilderness ParkPIN: 2921059069
Lucio BoscoloPIN: 3522049008 3522049014 3522049040 3522049103
Mt Baker MiddlePIN: 3021059031
Emerald DownsPIN: 1580600152 1221049003 1580600150 0121049020 1221049002
River Mobile Home ParkPIN: 0621059002 0621059001 0004200007
Hazelwood ES/Rainier MiddlePIN: 0921059123
Miles Sand & Gravel Co.PIN: 1921059002 1921059008 1921059010 1921059082 1921059044 1921059276 1921059277
BNSF RRPIN: 2421049006 2421049030 2421049033 2421049035 2421049037
Olympic MiddlePIN: 1921059192
Joseph SchulerPIN: 3622049003 3622049006 3622049010
Lea Hill ElementaryPIN: 0921059005
Cascade MiddlePIN: 5094400080
Issac Evans ParkPIN: 0721059032
BoeingPIN: 2521049105 2521049106 2521049107 2521049108 2521049113 2421049069 2421049089 2421049091 2421049092
Mountainview HighPIN: 0421059051
Les Grove ParkPIN: 1921059181 1921059182
Muckleshoot Reservation CemeteryPIN: 2021059047 2021059041
Ilalko ElementaryPIN: 3121059007
Insulate LLCPIN: 6649600040
Stewart ArdellaPIN: 3622049012
Roegner ParkPIN: 6655000024 6655000030 3021059325 3021059375
Auburndale ParkPIN: 0821059017
FAAPIN: 2021059030
Auburndale IIPIN: 7867000020
Mountain View CemeteryPIN: 1421049011 1421049017 1421049067 9262800341 9662800330
Auburn Golf CoursePIN: 0621059007 0621059004 0521059011
Gildo Rey ElementaryPIN: 3021059195
Pioneer ElementaryPIN: 1921059054
Auburn HighPIN: 1821059082
Meredith Hill ElementaryPIN: 0221049149
Arthur Jacobsen ElementaryPIN: 0421059057 0421059085
Dick Scobee ElementaryPIN: 0001000047
Green River Community CollegePIN: 0921059104 1621059047 1621059006 1621059003 1621059008 1621059026
Evergreen Heights ElementaryPIN: 1121049022
Fulmer FieldPIN: 2648000010
Chinook ElementaryPIN: 2121059038 2121059092
West Auburn HighPIN: 4463400005
Enrique & Clarita Santos JrPIN: 3522049015
Cameron ParkPIN: 1313500310
7th Day Adventist HQPIN: 2721059012 2721059009 2721059072 2721059007 2721059043 2721059021 2721059081 2721059005 2721059006
Cedar Lanes ParkPIN: 3021059044 3021059089 3021049052 3021059080
Universal Brass Inc.PIN: 0004000040
Scootie Brown ParkPIN: 1821059101
Terminal ParkPIN: 8581400530
Kennedy EndeavorsPIN: 0303510090
Pioneer CemeteryPIN: 0721059020
American Powder CoatingPIN: 8855500040
Mary Olson Farm ParkPIN: 0521059006 3222059031 3222059032
Lea Hill ParkPIN: 0921059020
Green Valley AssociatesPIN: 2121059160 2121059010
Holy Family ElementaryPIN: 1921059018 1921059290 1921059201 1921059258
GSA Ballfield ParkPIN: 2421049075 2421049077
Auburn Riverside HighPIN: 6655000020 6655000026
Veterans Memorial ParkPIN: 1821059327
Terminal Park ElementaryPIN: 1921059053
Brannan ParkPIN: 7338001230 0001000081
Muckleshoot CasinoPIN: 2021059001 2021059021 2021059046
Washington ElementaryPIN: 1821059060
Thomas AcademyPIN: 9360000135 9360000140 9360000146
Auburn Regional Medical CenterPIN: 0492500240
Luisito & Lucita CuaresmaPIN: 3522049042
Rotary Park - AuburnPIN: 2597500910 2921059045
Neely FarmPIN: 2121059083 2121059007
East Auburn Athletic FieldsPIN: 0421059060 0421059061 0421059062 0421059071 0421059004
Auburn AcademyPIN: 2721059038 2721059039 2721059011 2721059033 2721059094 2721059067 2721059042 2721059052 2721059014
Indian Tom ParkPIN: 1821059001
North Green River ParkPIN: 0521059119 3022059105 3022059054 3122059011 3222059113 0004200017 0004200016
−
October 2008
2,00002,0001,000
Feet
Major Road
!!!County Boundary
KC-WTD Sewer
KC-WTD Service Area
Auburn City Limits
Open Water
Potential RW Users
Agriculture
Cemetery
Commercial
Golf
Industrial
Irrigation
Lg Scale Res Irr
Nursery/Grnhouse
Park
School
Sports Facility
Potential Reclaimed Water Users
Within Auburn City Limits
The information included on this map has been compiled from a variety of sources and is
subject to change without notice. King County makes no representations or warranties,
express or implied, as to accuracy, completeness, timeliness, or rights to the use of such
information. This document is not intended for use as a survey product. King County shall
not be liable for any general, special, indirect, incidential, or consequential damages including,
but not limited to, lost revenues or lost profits resulting from the use or misue of the information
contained on this map. Any sale of this map or information on this map is prohibited except by
written permission of King County.
File Name: Q:\\WTD\Projects\BW_Reuse\Projects\auburn_users.mxd - Shari Cross
Data Source: King County
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Chapter 5
Wastewater System Analysis
This chapter describes the analyses completed as part of this Plan, in support of CIP development.
The specific analyses include hydraulic modeling of the City’s sewer conveyance system, assessing
I/I, identifying sewer extensions needed to provide service to the entire city, and developing system
requirements for incorporating an asset management tool into the City’s computerized maintenance
management system (CMMS). These analyses are described in more detail below.
5.1 Hydraulic Capacity Analysis
The purpose for updating the hydraulic model of the City’s sewer system was to incorporate facilities
constructed since the model was originally built, recalibrate the model with new King County flow
meter data, and provide an assessment of system capacities for current and projected wastewater
flows. The capacity assessment provides the basis for identifying improvements that may be
necessary for the Utility to achieve the adopted LOS discussed in Chapter 3. The capacity
assessment is summarized below and presented in more detail as Appendix B.
5.1.1 Hydrologic and Hydraulic Model
The hydraulic capacity analysis was completed using an H&H model of the City’s collection and
conveyance system. The City provided an existing model using the DHI MIKE URBAN modeling
platform for this analysis. The model was updated with those major sewer facilities not already
included. In addition, sewered areas and population were updated in the model using data provided
by the City, including GIS data, Puget Sound Regional Council (PSRC) population projections, and
updated zoning/land use planning.
The updated model was used to simulate base and wet weather wastewater flow for current and
projected (i.e., 20-year planning period) scenarios. The projected scenario incorporated estimated
future population and sewer area expansion. While future water conservation efforts may reduce the
overall volume of sewage discharged to the system, the effect of the efforts on the ability of the
system to convey wastewater is assumed insignificant and not incorporated in the modeling. The
simulated wet weather flow has a recurrence interval of 20 years, which is the LOS defined for
wastewater collection and conveyance (see Section 3).
The model hydrology was calibrated using data from the King County Decennial Flow Monitoring
Project, which is part of the County’s Conveyance System Improvement (CSI) program. There were 15
County flow monitoring locations in the Auburn system. King County also provided the calibrated
models of their system near Auburn. The resolution (number of flow meters used for the service
area) of these calibrated models was less than the City desired, but the County’s models provided a
useful starting point for calibrating the City’s model.
5.1.2 Assessment Criteria
The ratio of simulated depth to pipe diameter (d/D) for the 20-year flow was used to determine the
adequacy of existing and future conveyance system capacity. In an unpressurized pipe, or a pipe with
open-channel flow characteristics, the hydraulic grade line (HGL) is the elevation of the water surface
within the pipe, or the d value. In a pipe that is surcharged (pressurized flow), the HGL is defined by
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the elevation to which water would rise in an open pipe, or manhole, as shown in Figure 5-1. In
hydraulic terms, the HGL is equal to the pressure head measured above the invert of the pipe.
Figure 5-1. HGL for surcharged condition
Pipes that surcharge frequently do not meet the LOS and should be upsized (or the tributary I/I
reduced). Additionally, surcharging can reduce pipe lifespan and cause unexpected failures. If the
surcharge depth is significant, then there is a risk of sanitary sewer overflows (SSOs) or sewers
backing up into basements. Therefore, the freeboard, defined as the distance between the water
surface in the manhole and the ground surface, should be considered when assessing conveyance
system capacity. The amount of freeboard (distance between HGL and ground surface) for the
upstream manhole, in each surcharging pipe, is included in the model output table in Appendix B.
The approach for determining which pipes need to be upsized (to provide additional capacity) was
based on the amount of surcharging. If a surcharged (d/D > 1) pipe was less than 6 feet below the
ground surface, as simulated for the 1-in-20-year evaluation storm event, then the pipe was
identified as requiring an upsize (or capacity reclaimed through reduction of I/I). The depth of 6 feet
was selected because this is considered low enough beneath the ground surface to avoid back up of
sewer flow in basements. This criterion was evaluated for both existing and future (2020) conditions.
As flows increase in the future, City staff will need to monitor water surface elevations during large
storm events throughout the system to determine when pipes should be upsized. If the observed
surcharging increases to the point of risking property or becoming an SSO, then the pipe or pipes
should be upsized (or I/I reduction sought). This approach will help to provide confidence that the
City has adequate capacity for conveying the design flows without spending more capital dollars than
necessary.
5.1.3 Existing-Conditions Evaluation
The existing-conditions scenario represents the existing conveyance system under current flow
conditions during the 20-year wet weather event. The results of this analysis identify any hydraulic
deficiencies currently within the system. Based on discussions with City staff, the model predictions
generally support their observations of no current capacity problems.
Highlights of the modeling results are discussed below. The detailed results (i.e., modeled sewer
statistics) for the current (existing) conditions planning scenario are shown in Appendix B.
D d
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5.1.3.1 Gravity Sewers
The existing-conditions modeling revealed surcharging throughout the conveyance system with more
than 100 sewer pipes showing mostly minor surcharging. Surcharged sewers include all City-owned
pipes with a modeled d/D ratio of greater than 1.0. In addition, flooding to the ground surface (i.e.,
SSO) was predicted at a single location, along Boundary Boulevard SW on the southwestern limits of
the city. The location of the SSO and surcharged sewer pipes are shown on Figure 5-2, and listed in
Appendix B. The freeboard, predicted by the model, for those pipes with surcharge, is provided in
Appendix B.
The location predicted to have a SSO by the model is adjacent to King County’s Auburn West Valley
Interceptor. King County is currently planning to change the discharge location of the upstream
Pacific Pumping Station from this interceptor to the Auburn West Interceptor. This change will reduce
the hydraulic grade line downstream of the predicted SSO in the City, which would have a positive
effect. In addition, the simulated SSO is not corroborated by City observations. Therefore, no capital
project is proposed for this location.
A majority of the identified surcharging sewer pipes are adjacent to King County sewer pipes. The
surcharging at these locations is due mostly to the hydraulic grade line in the County’s sewer pipes,
and not because of insufficient capacity in the City’s sewer pipes. None of these locations had
surcharge within 6 feet of the ground surface. However, the City should observe these locations
during wet weather in the event the surcharging increases. If chronic surcharging near the ground
surface is observed, then King County should be notified. King County addresses capacity issues of
its assets with its Conveyance System Improvements (CSI) program.
Surcharging in the remaining (City) sewer pipes was minor. The surcharge in each sewer pipe was
more than 6 feet below the ground surface. Therefore, no capital projects are proposed to address
capacity in the City’s conveyance system. Sewer pipes simulated to surcharge should be observed
during wet weather events to determine if, and when, improvements may be required to prevent
basement backups or SSOs.
5.1.3.2 Pump Stations and Force Mains
Pumping station and force main flow statistics are listed in Table 5-1. The locations of the stations
are shown in Figure 5-2. The table shows the model estimates for inflows to the pumping stations.
These flow values are compared to the stations rated flow capacity. The F-Street pumping station is
the only location where the model estimated flow is higher than the rated capacity. The estimated
capacity shortfall is relatively small, about 30 percent, and City staff reported no issues at this
location. This model result should be further confirmed by frequent monitoring of pump run times
(SCADA information), field observations of water levels in the wet well and upstream sewers during
wet weather, or upstream flow monitoring as part of CIP project 9 (see Chapter 7).
The table also shows the maximum force main velocity, based on the pumping station rated capacity.
In general, the maximum velocity should not exceed 7 feet per second to avoid increased pump
power consumption. The only pumping station with an excessive maximum velocity is Ellingson Road.
Pump operating procedures at this pumping station should be evaluated in an effort to address the
excessive force main velocity. However, because of the short length of the force main, approximately
50 feet, this is not a major concern.
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Table 5-1. Simulated 20-Year Flows to Pumping Stations, Existing Conditions Scenario
Pumping
stationa
Current pumping rated
capacityb,
gallons per minute (gpm)
No. of
pumps
Existing peak 20-year
flow, gpm
Force main size,
inches
Maximum force main
velocityc, fps
Area 19 325 2 22 6 3.7
Terrace View 675 2 21 8 4.3
Ellingson Road 1,527 2 1,054 8 9.7
F Street 400 2 528 8 2.6
Riverside 400 2 54 6 4.5
R Street 100 2 79 4 2.6
Peasley Ridge 275 2 31 6 3.1
Rainer Ridge 200 2 109 6 2.3
Valley Meadows 125 2 63 4 3.2
22nd Street 550 2 167 6 6.2
D Street 400 2 97 6 4.5
8th Street 150 2 9 4 3.8
North Tapps 510 2 55 8 3.3
Verdana 2,000 3 727 12 5.7
Dogwood 300 2 151 6 3.4
a. The Auburn 40 pump station was not modeled for the plan because it is relatively new and serves a small area in the city.
b. The rated pumping capacity, or firm capacity, is based on pump station operation without the use of one (redundant) pump. Use of
all the pumps at a pump station does not provide pumping redundancy as per U.S. EPA requirements.
c. The maximum velocity based on firm pumping capacity. Velocities exceeding 7 feet per second (fps) are generally to be avoided.
Velocities in excess of 7 fps result in significant increases in pump power consumption.
5.1.4 Future-Conditions Evaluation
The results of the future-conditions scenario modeling are described in this section. This scenario
represents the conveyance system with any known, future improvements, and estimated future flows
during the 20-year wet weather event. Future flows for 2020 and 2034, based on projected growth
in the city, were simulated. The detailed results (i.e., modeled sewers) for the future-conditions
scenario are provided in Appendix B.
5.1.4.1 Gravity Sewers
The future model incorporated King County’s planned improvement to the Pacific Pumping Station
force main. As described above, this planned improvement will redirect current pump station
discharge from King County’s West Valley Interceptor to the County’s West Interceptor. This change
in discharge location eliminated the flooding predicted at Boundary Boulevard for existing conditions,
for both 2020 and 2034 future conditions.
There was no predicted flooding in the City’s conveyance system for the future conditions. The
locations of surcharged sewer pipes for the 2020 and 2034 future conditions are shown on Figure
5-2 and listed in Appendix B. The remaining freeboard predicted by the model, for those pipes with
surcharge, is provided in Appendix B.
GreenRiver
MillCreek
167
18
AUB
U
R
N
W
A
Y
S
B
S
T
N
W
37TH ST NE
WE
S
T
V
A
L
L
E
Y
H
W
Y
N
W
15TH ST NW
W MAIN ST
K
E
R
S
E
Y
W
A
Y
S
E
53RD ST SE
A
U
B
U
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N
W
A
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SE 304TH ST
SE 312TH ST
11
2
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A
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ELLINGSON RD SW
WhiteRiver
15TH ST SW
PE
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R
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W
CL
A
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S
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N
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King County
Pierce County
BOUNDARY BLVD SW
Pacific
Dogwood
Verdana
Safeway
Area 19
R Street
F Street
Auburn 40
Riverside8th Street
North Tapps
22nd Street
Auburn Jail
Terrace View
Rainier RidgePeasley Ridge
Lakeland Hills
Valley Meadows
Ellingson Road
Issac Evans Park
Auburn Golf Course
Auburn Justice Center
Auburn Valley Humane Society
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 5-2WASTEWATER MODELNETWORK AND RESULTS -EXISTING CONDITIONS, 20-YR FLOW
3,500 0 3,500 7,000
Feet N
P:\Auburn\145308 Auburn Sewer Comp Plan Update\_GIS\Projects\Plan Figures\fig_4-2_ExistingWastewaterConveyanceSystem11x17.mxd
L E G E N D
Simulated surcharge
Simulated flooding
Model sewer pipe
Auburn sewer
King County sewer
Auburn Pump Station
King County Pump Station
Private Pump Station
Major Roads
Street
Auburn City Boundary
County line
Muckleshoot Indian
Reservation
Streams/Rivers/Ponds
City of Auburn Comprehensive Sewer Plan Chapter 5
5-7
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
The future 2034 model results are shown mostly for reference. No capital projects are proposed
based on these model results because the uncertainty associated with predictions this far in the
future is very high. However, the 6-year planning horizon is more certain, and making decisions for
this time period is necessary for sound management of the City’s sewer utility. Therefore, the
discussion here will focus on the 2020 model results.
There were about 125 sewer pipes predicted to surcharge for the future (2020) conditions, which
was not significantly more than the existing-conditions evaluation. Similar to the existing-conditions
scenario, many surcharged pipes were adjacent to King County pipes. These are not considered to
be issues for the City, as described previously. The predicted surcharge in the remaining pipes was
mostly minor with the hydraulic grade line being more than 6 feet beneath the ground surface.
There were two locations where the surcharge was less than 6 feet below ground: upstream and
downstream of the Verdana Pumping Station. Neither of these locations has a simulated water
surface within 4 feet of the ground, so there is minimal risk of SSO, based on the model results. The
surcharge upstream of the pumping station appears to be caused by relatively small (8-inch
diameter) pipes (according to the City’s GIS) entering the station. This information should be field
verified and water levels in the upstream sewer pipes monitored during wet weather prior to a capital
project being developed. The surcharge downstream of the pumping station is also downstream of a
flow diversion manhole installed during construction of the Verdana Pumping Station. This flow
diversion potentially provides the City flexibility in operation to reduce the predicted surcharging by
sending more flow away from the surcharging. Again, no capital project should be developed to
address this surcharging until visual monitoring confirms excessive surcharge, and operational
changes are deemed insufficient to address the surcharge.
As a result of the future-conditions (2020) hydraulic analysis, no sewer pipe replacement capital
projects are proposed.
5.1.4.2 Pump Stations and Force Mains
Pumping station flow statistics are listed in Table 5-2. The locations of the stations are shown in
Figure 5-3. Similar to the existing-conditions modeling, the F-Street Pumping Station is shown to
have insufficient firm capacity. This pumping station is not currently recommended to be replaced,
based on the same reasoning explained in the existing-conditions section. Future flow metering data,
including data developed based on CIP project 9 (see Chapter 7), will help add fidelity to the
hydraulic model and will shape future evaluations of the conveyance system.
Chapter 5 City of Auburn Comprehensive Sewer Plan
5-8
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Table 5-2. Simulated 20-Year Flows to Pumping Stations, Future (2020) Conditions Scenarioa
Pumping stationb Current pumping rated capacityc, gpm No. of pumps Existing peak 20-year flow,
gpm
Area 19 325 2 22
Terrace View 675 2 29
Ellingson Road 1,527 2 1,055
F Street 400 2 535
Riverside 400 2 63
R Street 100 2 82
Peasley Ridge 275 2 42
Rainer Ridge 200 2 116
Valley Meadows 125 2 71
22nd Street 550 2 175
D Street 400 2 102
8th Street 150 2 9
North Tapps 510 2 92
Verdana 2,000 3 953
Dogwood 300 2 154
a. The maximum force main velocity is not provided for future conditions because it is estimated based on the pumping stations firm
capacity, and not modeled flows. So, the maximum force main velocities are the same for existing and future conditions.
b. The Auburn 40 pump station was not modeled for the plan because it is relatively new and serves a small area in the city.
c. The rated pumping capacity, or firm capacity, is based on pump station operation without the use of one (redundant) pump. Use of
all the pumps at a pump station does not provide pumping redundancy as per U.S. EPA requirements.
GreenRiver
MillCreek
167
18
AUB
U
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N
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A
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S
B
S
T
N
W
37TH ST NE
WE
S
T
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A
L
L
E
Y
H
W
Y
N
W
15TH ST NW
W MAIN ST
K
E
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E
Y
W
A
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S
E
53RD ST SE
A
U
B
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N
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A
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SE 304TH ST
SE 312TH ST
11
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ELLINGSON RD SW
WhiteRiver
15TH ST SW
PE
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W
CL
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King County
Pierce County
BOUNDARY BLVD SW
Pacific
Dogwood
Verdana
Safeway
Area 19
R Street
F Street
Auburn 40
Riverside8th Street
North Tapps
22nd Street
Auburn Jail
Terrace View
Rainier RidgePeasley Ridge
Lakeland Hills
Valley Meadows
Ellingson Road
Issac Evans Park
Auburn Golf Course
Auburn Justice Center
Auburn Valley Humane Society
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 5-3WASTEWATER MODELNETWORK AND RESULTS -FUTURE CONDITIONS, 20-YR FLOW
3,500 0 3,500 7,000
Feet N
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L E G E N D
2020 simulated surcharge
2034 simulated surcharge
Model sewer pipe
Auburn sewer
King County sewer
Auburn Pump Station
King County Pump Station
Private Pump Station
Major Roads
Street
Auburn City Boundary
County line
Muckleshoot Indian
Reservation
Streams/Rivers/Ponds
City of Auburn Sewer Comprehensive Plan Chapter 5
5-11
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
5.2 Inflow and Infiltration
The current levels of I/I in the Auburn sewer system do not appear to be causing capacity-related
issues. However, pipes will continue to degrade, allowing more infiltration into the system, and
populations are expected to rise within the SSSA, both increasing flows to the sewer system. If I/I
capacity-related issues occur in the future, then reducing the amount of I/I in the collection system
can improve the hydraulic capacity of the system such that some pipes may not need to be replaced.
In addition, I/I reduction can help to prevent some types of structural failures and reduce M&O
requirements. It is recommended that Auburn complete an initial I/I investigation to augment
currently available data and prepare a baseline that future studies can be compared against. This
information will help to inform the decision when it is appropriate to fund and implement an actual
I/I management program.
The primary components of an I/I management program are shown in Figure 5-4. This figure depicts
the necessary components to successfully manage the project (Program Charter), identify the issues
(Problem Determination), identify proper corrections (Correction Implementation), evaluate the work
completed (Effectiveness Evaluation), and set a long-range plan (Long-Range Planning).
5.2.1 Initial Inflow and Infiltration Assessment
The King County flow monitoring included 15 flow meter basins that impact City of Auburn sewers.
Two of these basins are located outside of Auburn’s purview: one is located in Algona and in the
other basin, while within city limits, the sewers are owned and maintained by LUD. These basins
were compared to each other and ranked based on high, medium, and low I/I based on the 25-year
I/I rates normalized on inch-diameter/miles of the flow meter basin. The results of this are shown in
Figure 5-5. The two basins located outside of Auburn’s control that were evaluated showed high
levels of I/I. It is recommended that Auburn share the results of this evaluation with Algona and LUD.
King County has an I/I standard of 1,100 gpad based on peak 20 year I/I rates for sewered areas.
Values in excess of 1,100 gpad are considered to be excessive. The area is based on King County’s
GIS layer “sewerland”. This file delineates King County’s service area as sewered or unsewerable
(parks, cemeteries, etc.). The calculated I/I rates for each sewer basin (see Appendix B, Figure 3-1)
are presented in Table 5-3. This shows that all but two basins have excess I/I based on King County
standards.
Table 5-3. King County I/I Rates
Sewer Basin Sewered Area (ac) I/I (gpad) Sewer Basin Sewered Area (ac) I/I (gpad)
ABN008 270 1,630 LakelandHills_WW 716 325
ABN022 393 2,809 LKH001A 318 2,067
ABN023 106 4,452 MSTTR02A 1,476 2,186
ABN024 136 833 MSTTR22A 851 6,237
ABN027 397 1,458 MSTTR48 895 4,197
ABN032 175 11,161 WINT003 96 7,996
AUBRN53 255 21,251 WINT038 723 1,452
AUBWV016 1,513 4,561
The U.S. Environmental Protection Agency (EPA) recognizes that many collection system SSOs are
the result of high flows associated with wet weather events. Consequently, in some instances,
language has been added to National Pollutant Discharge Elimination System (NPDES) permits
requiring the permittee to take actions to reduce I/I within the sanitary collection system. To be
proactive, it is recommended that Auburn further evaluate I/I rates with additional flow monitoring
and data evaluation.
Chapter 5 City of Auburn Comprehensive Sewer Plan
5-12
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
Figure 5-4. Primary components of an I/I management program
GreenRiver
LakeTapps
BigSoos C re e k
MillCreek
167
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37TH ST NE
WE
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L
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H
W
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N
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15TH ST NW
W MAIN ST
K
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A
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53RD ST SE
A
U
B
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SE 304TH ST
SE 312TH ST
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ELLINGSON RD SW
Algona
Pacific
Sumner
Kent
WhiteRiver
15TH ST SW
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Pierce County
King County
Pacific
Dogwood
Verdana
Safeway
Area 19
R Street
F Street
Auburn 40
Riverside8th Street
North Tapps
22nd Street
Auburn Jail
Terrace View
Rainier RidgePeasley Ridge
Lakeland Hills
Valley Meadows
Ellingson Road
Issac Evans Park
Auburn Golf Course
Auburn Justice Center
Auburn Valley Humane Society
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 5-5INFLOW AND INFILTRATIONCOMPARATIVE LEVELS3,500 0 3,500 7,000
Feet N
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L E G E N D
Flow Meter Locations
Auburn Sewers
Bonney Lake Sewers
King County Sewers
Kent Sewers
Lakehaven Sewers
MIT Sewers
Private Sewers
Auburn Pump Station
King County Pump Station
I/I Level
High
Medium
Low
High/Not COA
Major Roads
StreetOther Sewer Utilities within City of Auburn
City of Algona
Soos Creek Water and Sewer District
City of Kent
Lakehaven Utility District
Auburn City Boundary
County line
Streams/Rivers/Ponds
Political Boundaries
City of Auburn Sewer Comprehensive Plan Chapter 5
5-15
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City of Auburn Comprehensive Sewer Plan_FINAL.docx
5.3 Sewer Extensions
A City goal is to be able to serve every parcel within city limits with sanitary sewer service. Currently
many areas within city limits are served by onsite systems (septic tanks) or are undeveloped.
The City’s GIS information was used to lay out an extension plan and to determine where gravity
service was feasible. This was accomplished by comparing inverts of the existing collection system,
topography, assuming minimal allowable slopes of 0.5 percent, and the location of unserved parcels.
In some locations, gravity service appears to be infeasible and pump stations are required to convey
sewage to existing infrastructure. It is estimated that up to six new pump stations may be required to
have citywide sewer service. While the pump stations were not individually sized, they would all be
small in nature, generally less than 500 gpm. In addition, gravity service is not a viable option for
about 64 parcels within city limits. These parcels will have to use mechanical means, such as
individual grinder pumps, to be connected to the City’s system. The proposed conceptual sewer
extension plan is shown on Figure 5-6.
City wide, the plan estimates the need for the following capital improvements and, for planning-level
construction cost estimates (in 2014 dollars), the following unit costs are recommended:
• 261,250 feet of 8-inch-diameter gravity pipe: $500/foot
• 8,650 feet of 4- to 8-inch-diameter force main: $400/foot
• 6 pump stations: $500,000/each (assuming no property acquisition)
• 64 non-gravity services (grinder pumps or equivalent): $10,000/each
• 7,500 feet of 2-inch-diameter low-pressure force main: $250/foot
The city was subdivided into concentrated groupings of proposed sewer extensions. Estimated
construction costs for sewer extensions were calculated for each basin based on the number of
assets within their area and the above unit costs. The results of this are shown in Figure 5-7. The
total estimated construction cost to extend service to all parts of the city is estimated to be around
$140 million. In general, such future extensions would be constructed by future development or by
the properties benefiting from such extensions.
Pacific
PUMP STATION
Dogwood
PUMP STATION
Verdana
PUMP STATION
Safeway
PUMP STATION
Area 19
PUMP STATION
R Street
PUMP STATION
F Street
PUMP STATION
Auburn 40
PUMP STATION
Riverside
PUMP STATION8th Street
PUMP STATION
North Tapps
PUMP STATION
22nd Street
PUMP STATION
Auburn Jail
PUMP STATION
Terrace View
PUMP STATION
Rainier Ridge
PUMP STATIONPeasley Ridge
PUMP STATION
Lakeland Hills
PUMP STATION
Valley Meadows
PUMP STATION
Ellingson Road
PUMP STATION
Issac Evans Park
PUMP STATION
Auburn Golf Course
PUMP STATION
Auburn Justice Center
PUMP STATION
Auburn Valley Humane Society
PUMP STATION
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SR 18-WEST
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SE 304TH ST
S 277TH ST
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STUCK RIVER DR SE
15TH ST SW
2ND ST E
W MAIN ST
15TH ST NW
LAKE TAPPS PKWY SE
53RD ST SE
41ST ST SE
51
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AUBURN-BLACK DIAMOND RD SE
SR
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SR 18-EAST RAMP
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SE 316TH PL
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15TH ST NE
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56TH ST SE
RIVE
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28TH ST NE
35TH WAY SE
BOUNDARY BLVD SW
30TH ST NE
EL
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LU
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6
T
H
A
V
E
S
E
49TH ST N
E
1
0
2
N
D
A
V
E
S
E
TE
R
R
A
C
E
D
R
N
W
ELLINGSON RD SW
SKYWAY
L
N
S
E
HI
C
R
E
S
T
D
R
N
W
O
S
T
S
E
10TH ST SE
D
S
T
S
W
17
6
T
H
A
V
E
E
SE 3
2
6
T
H
P
L
SE 295TH ST
20TH ST SE
SE 286TH ST
V
S
T
S
E
66TH ST SE
14
8
T
H
A
V
E
S
E
F
S
T
S
W
V C
T
S
E
24TH ST NW
12
8
T
H
P
L
S
E
72ND ST SE
16TH ST SE
S 312TH ST
6TH ST NW
42ND ST NE
13TH ST SE
B PL NW
3RD ST NW
SE
3
1
2
T
H
W
A
Y
2ND ST SE
SE 294TH ST
Z
S
T
S
E
73RD ST SE
55
T
H
P
L
S
S 292ND ST
EL
M
S
T
S
E
ELM LN SE
PE
A
R
L
A
V
E
S
E
10
5
T
H
A
V
E
S
E
L
S
T
N
E
SE 285TH ST
52
N
D
P
L
S
9TH ST SE
67
T
H
L
N
S
E
OUTLET COLLECTION WAY SW
SE 307TH PL
I
S
A
A
C
A
V
E
S
E
H
A
Z
E
L
A
V
E
S
E
28TH ST SE
11TH ST NE
T
S
T
N
E
15TH ST SE
SE 42ND ST
26TH ST NE
SE 299TH PL
45TH
S
T
N
E
J
S
T
N
E
S 303RD PL
SE 308TH PL
SE 281ST ST
SE 290TH PL
HE
A
T
H
E
R
A
V
E
S
E
10
9
T
H
P
L
S
E
RA
N
D
A
L
L
A
V
E
S
E
MAPLE DR SE
S 314T
H
S
T
6TH ST SE
K
S
T
N
E
30TH ST NW
NO
B
L
E
C
T
S
E
U
S
T
S
E
SE 289TH ST
19TH ST SE
SE 297TH ST
5
7
T
H
D
R
S
E
WA
R
D
A
V
E
S
E
12
9
T
H
P
L
S
E
I
P
L
N
E
21ST ST SE
SE 307TH ST
33RD ST SE
55TH ST SE
S 324TH ST SE 323RD ST
14TH ST NW
WE
S
T
E
R
N
A
V
E
N
W
11
7
T
H
P
L
S
E
PI
K
E
S
T
S
E
N
S
T
S
E
SE 292ND ST
OL
Y
M
P
I
C
S
T
S
E
11
2
T
H
P
L
S
E
42ND PL NE
SE 296TH ST
PARK AVE NE
SE 306TH ST
13
4
T
H
P
L
S
E
D
P
L
S
E
11
0
T
H
P
L
S
E
5TH ST NE
M DR NE
35TH ST NE
F
S
T
N
E
8TH ST SW
SE 302ND PL
U
C
T
N
W
KA
T
H
E
R
I
N
E
A
V
E
S
E
40TH ST NE
59
T
H
A
V
E
S
SE 300TH ST
16TH ST NW
JA
S
M
I
N
E
A
V
E
S
E
13
3
R
D
A
V
E
S
E
9T
H
S
T
N
E
63
R
D
P
L
S
2ND ST NE
27TH ST SE
6TH ST NE
CROS
S
S
T
S
E
10
7
T
H
A
V
E
S
E
O
C
T
S
E
J
A
M
E
S
A
V
E
S
E
SE 305TH PL
S 307TH ST
UD
A
L
L
A
V
E
S
E
SE 288TH PL
KE
N
N
E
D
Y
A
V
E
S
E
SE 314TH PL
56
T
H
P
L
S
SE 313TH ST
V PL SE
SE 302ND ST
S 297TH PL
SE 3
1
8
T
H
P
L
12
1
S
T
P
L
S
E
56
T
H
C
T
S
26TH ST NW
SE 293RD ST
37
T
H
P
L
S
E
12
5
T
H
A
V
E
S
E
1
1
3
T
H
P
L
S
E
12
0
T
H
A
V
E
S
E
SE 304TH PL
S 329TH PL
S 292ND PL
71ST ST SE
SE 315TH ST
S 328TH ST
49TH ST SE
S 321ST ST
60
T
H
P
L
S
SE 321ST PL
67T
H
C
T
S
E
SE 282ND
W
A
Y
FR
A
N
K
L
I
N
A
V
E
S
E
7TH ST NE
12
4
T
H
P
L
S
E
S
S
T
S
E
SE 322ND PL
3RD CT SE
13
8
T
H
A
V
E
S
E
S 298TH PL
S 326TH LN
44TH ST SE
L
P
L
N
E
SE 319TH ST
SE 325TH PL
SE 315TH PL
18
1
S
T
A
V
E
E
10
0
T
H
A
V
E
S
E
W
E
S
L
E
Y
P
L
S
E
SE 306TH PL
SE 305TH ST
23RD ST NE
12
3
R
D
A
V
E
S
E
17
1
S
T
A
V
E
E
U
S
T
N
E
PO
P
L
A
R
S
T
S
E
JO
R
D
A
N
A
V
E
S
E
SE 306TH CT
53R
D
A
V
E
S
S 294TH PL
O
C
T
N
E
SE 283RD ST
59
T
H
P
L
S
L
C
T
N
E
W PL NW
E
V
E
R
G
R
E
E
N
W
A
Y
S
E
PI
K
E
S
T
N
E
30TH ST NE
37TH ST SE
SE 288TH PL
5
7
T
H
P
L
S
25TH ST SE
12
1
S
T
P
L
S
E
F
S
T
S
E
D
S
T
S
E
D
S
T
S
E
SE 282ND ST
C
S
T
S
E
L
S
T
S
E
36TH
S
T
S
E
L
S
T
S
E
N
S
T
S
E
11
6
T
H
A
V
E
S
E
29TH ST NW
8TH ST NE
K
S
T
S
E
55
T
H
A
V
E
S
SE 295TH ST
J
S
T
N
E
R
S
T
N
E
K
S
T
N
E
D
S
T
S
E
EL
M
S
T
S
E
PI
K
E
S
T
S
E
SR 18-WES
T
R
A
M
P
H
S
T
S
E
72ND ST SE
D
S
T
N
E
SE 286TH ST
B
S
T
N
W
SE 290TH PL
SR 18-EAS
T
R
A
M
P
H
S
T
N
E
L
S
T
N
E
56
T
H
A
V
E
S
SE 294TH ST
11
2
T
H
A
V
E
S
E
SE 288TH ST
23RD ST SE
E
S
T
S
E
10
8
T
H
A
V
E
S
E
I
S
T
S
E
10
8
T
H
A
V
E
S
E
E
L
I
Z
A
B
E
T
H
A
V
E
S
E
O
S
T
N
E
A
S
T
S
E
N S
T
N
E
10
8
T
H
A
V
E
S
E
11
2
T
H
A
V
E
S
E
O S
T
N
E
SE 315TH PL
2ND ST SE
4TH ST NE
SE 295TH ST
D
S
T
S
E
SE 310TH ST
51
S
T
A
V
E
S
R
S
T
N
W
SE 302ND ST
L E G E N D
Proposed Sewers
Proposed Gravity
Proposed LPFM
Proposed Force Main
Proposed Pump Station
Ex. COA Pump Station
Ex. King County Pump Station
Ex. Other Pump Station
King County Sewers
Force Main
Gravity Main
Auburn Sewers
Force Main
Gravity Main
Private Force Main
Private Gravity Main
City of Auburn Sewer Service Area
County line
Buildings
Paved Surfaces
Water Bodies
Wetlands
Parcels
Steep Slopes
FIGURE 5 - 6
CITY OF AUBURN COMPREHENSIVE SEWER PLAN
EXISTING AND PROPOSED SEWER FACILITIES
1,000 0 1,000 2,000Feet
P:\Auburn\145308 Auburn Sewer Comp Plan Update\_GIS\Projects\Plan Figures\fig_5-2_SewerExtensions.mxd
1 inch = 1,000 feet
October 2015
N
King County
Pierce County
SR
1
6
7
SR
1
8
A
S
T
S
E
AU
B
U
R
N
W
A
Y
S
C
S
T
S
W
B
S
T
N
W
AU
B
U
R
N
W
A
Y
N
I
S
T
N
E
13
2
N
D
A
V
E
S
E
WE
S
T
V
A
L
L
E
Y
H
W
Y
N
W
M
S
T
S
E
51
S
T
A
V
E
S
8TH ST E
12
4
T
H
A
V
E
S
E
24TH ST E
BU
T
T
E
A
V
E
15TH ST SW
12
2
N
D
A
V
E
E
2ND ST E
SE 312TH ST
S 277TH ST
C
S
T
N
E
C
S
T
N
W
198TH
A
V
E
E
AUB
U
R
N
-
B
L
A
C
K
D
I
A
M
O
N
D
R
D
S
E
53RD ST SE
9TH ST E
G
R
E
E
N
R
I
V
E
R
R
D
WE
S
T
V
A
L
L
E
Y
H
W
Y
S
W
EDWARDS RD E
41ST
S
T
S
E
STUCK
R
I
V
E
R
D
R
SE 288TH ST
EA
S
T
V
A
L
L
E
Y
H
W
Y
S
E
16TH ST E
K
E
R
S
E
Y
W
A
Y
S
E
SE 304TH ST
12TH ST E1
9
0
T
H
A
V
E
E
M
S
T
N
E
PER
I
M
E
T
E
R
R
D
8TH ST NE
SE 272ND ST
37TH ST NW
ACADE
M
Y
D
R
S
E
SE LAKE HOLM RD
GREEN VALLEY RD
ORA
V
E
T
Z
R
D
S
E
VA
L
E
N
T
I
N
E
A
V
E
S
E
SE 282ND ST
14
7
T
H
A
V
E
S
E
14
4
T
H
A
V
E
S
E
17TH ST SE
55
T
H
A
V
E
S
1ST AVE SE
18
5
T
H
A
V
E
E
D
S
T
N
W
A
S
T
N
E
JO
V
I
T
A
B
L
V
D
EA
S
T
B
L
V
D
(
B
O
E
I
N
G
)
10
8
T
H
A
V
E
T
A
C
O
M
A
P
O
I
N
T
D
R
E
14
8
T
H
A
V
E
S
E
EM
E
R
A
L
D
D
O
W
N
S
D
R
N
W
D
S
T
N
E
M
S
T
N
W
169
T
H
A
V
E
E
S 287TH ST
S
C
E
N
I
C
D
R
S
E
S 316TH ST
WE
S
T
B
L
V
D
(
B
O
E
I
N
G
)
H
S
T
N
W
44TH ST NW
14
8
T
H
A
V
E
E
13
7
T
H
A
V
E
E
SE
G
R
E
E
N
V
A
L
L
E
Y
R
D
TH
O
R
T
O
N
A
V
E
S
W
SE 310TH ST
LEA HILL
R
D
S
E
17TH S
T
E
11
8
T
H
A
V
E
S
E
S 3RD AVE
S 3
6
4
T
H
P
L
S 384TH ST
ROY RD SW
J
S
T
N
E
1
2
6
T
H
A
V
E
E
S
2
7
2
N
D
W
A
Y
BR
I
D
G
E
T
A
V
E
S
E
MO
N
T
E
V
I
S
T
A
D
R
S
E
L
S
T
S
E
C
O
T
T
A
G
E
R
D
E
FO
S
T
E
R
A
V
E
S
E
F
S
T
S
E
1ST ST E
G
S
T
S
E
NO
R
M
A
N
A
V
E
S
E
SE 284TH ST
H
O
W
A
R
D
R
D
I
S
T
N
W
14
2
N
D
A
V
E
E
7
8
T
H
A
V
E
S
13
5
T
H
A
V
E
S
E
3RD ST E
8
6
T
H
A
V
E
S
27TH ST E
R
S
T
N
W
85
T
H
A
V
E
S
K
S
T
S
E
S 336TH ST
C
S
T
S
E
SE 301ST ST
SE 287TH ST
2
0
0
T
H
A
V
E
E
Q
U
I
N
C
Y
A
V
E
S
E
29TH ST NW
MI
L
W
A
U
K
E
E
A
V
E
N
56
T
H
A
V
E
S
SKYWAY LN
S
E
32ND PL NE
2
1
1
T
H
A
V
E
E
45TH ST
N
E
7TH ST E
14
0
T
H
A
V
E
S
E
10
5
T
H
A
V
E
S
E
U
C
T
N
W
SE 270TH PL
SE 273RD PL
SE 300TH ST
SR
1
6
7
11
8
T
H
A
V
E
S
E
51
S
T
A
V
E
S
SR
1
6
7
SR
1
6
7
SR 18
SE 284TH ST
SR 18
12
4
T
H
A
V
E
S
E
SR
1
6
7
SE 272ND ST
14
4
T
H
A
V
E
S
E
S
R
1
6
7
S 277TH ST
14
2
15
9
1
5
16
19
8
18
3
4
13
2524
17 6
10
22
21
7
11
20
23
12
COMPREHENSIVE SEWER PLAN
October 2015
L E G E N D
Proposed Gravity Extension
Proposed LPFM Extension
Proposed Force Main Extension
Proposed Pump Station
Existing Pump Stations
King County Sewers
Existing Sewers
Major Roads
Street
County Line
Streams
Water
Parcels
City of Auburn Sewer Service Area
P:\Auburn\145308 Auburn Sewer Comp Plan Update\_GIS\Projects\Plan Figures\fig_5-7_SewerExtensionsCosts.mxd
FIGURE 5-7SEWER EXTENSIONFOR UNSEWERED AREASESTIMATED COSTS
4.050' 8" Pipe - $2,025,000
550' FM - $220,000
1 PS - $500,000
Total - $2,745,000
7,800' 8" Pipe - $3,900,000
6,600' 8" Pipe - $3,300,000
12,200' 8" Pipe - $6,100,000
3,900' 8" Pipe - $1,950,000
5,200' 8" Pipe - $2,600,000
4,800' 8" Pipe - $2,400,000
13 Grinder Pumps - $130,000
1,000' 2" FM - $250,000
Total - $2,780,000
24,000' 8" Pipe - $12,000,000
4 Grinder Pumps - $40,000
1,000' 2" FM - $250,000
Total - $12,290,000
24,200' 8" Pipe - $12,100,000
850' FM - $340,000
1 PS - $500,000
Total - $12,940,000
5,000' 8" Pipe - $2,500,000
7,000' 8" Pipe - $3,500,000
3,100' 8" Pipe - $1,550,000
8,000' 8" Pipe - $4,000,000
2,650' 8" Pipe - $1,325,000
3,200' 8" Pipe - $1,600,000
3,950' 8" Pipe - $1,975,000
4,400' 8" Pipe - $2,200,000
2,250' 8" Pipe - $1,125,000
5,750' 8" Pipe - $2,875,000
2,000' 8" Pipe - $1,000,000
3,950' 8" Pipe - $1,975,000
4,650' 8" Pipe - $2,325,000
2,350' FM - $940,000
1 PS - $500,000
Total - $3,765,000
4,650 8" Pipe - $2,325,000
900' FM - $360,000
1 PS - $500,000
38 Grinder Pumps - $380,000
4,300' 2" FM - $1,075,000
Total - $11,740,000
8,500' 8" Pipe - $4,250,000
2,000 FM - $800,000
1 PS - $500,000
Total - $5,550,000
Rest of City
77,350' 8" Pipe -
$38,675,000
5 Grinder Pumps - $50,000
800' 2" FM - $200,000
Total - $38,925,000
7,900' 8" Pipe - $3,950,000
2,000 FM - $800,000
1 PS - $500,000
Total - $5,250,000
N
3,500 0 3,500 7,000
Feet
City of Auburn Sewer Comprehensive Plan Chapter 5
5-21
Use of contents on this sheet is subject to the limitations specified at the end of this document.
City of Auburn Comprehensive Sewer Plan_FINAL.docx
5.4 Asset Management
All utilities manage their assets in one way or another through maintenance practices, capital
improvement projects, and R&R activities. Asset management is a systematic approach to
maintaining assets in good working order to minimize future costs of maintaining and replacing
them, especially to avoid costly deferred maintenance. The best practices for asset management
involve systematically basing choices on an understanding of asset condition and performance,
risks, and costs in the long term. Asset best practices include:
• having knowledge about assets and costs (i.e., detailed inventories)
• maintaining desired LOSs
• taking a life-cycle approach to asset management planning
• implementing the planned solutions to provide reliable, cost-effective service
• establishing funding levels and rates to support ongoing infrastructure rehabilitation or
replacement projects
The first step to effectively managing sewage assets is to establish LOS goals for the City as
described in Chapter 3 of this Plan. The second step is preparing a comprehensive inventory of the
assets. The next steps include performing asset assessments and economic analyses to estimate
life-cycle costs and the risk associated with each of the City’s wastewater assets.
The 2009 Comprehensive Sewer Plan included development of an economic life assessment tool to
help with asset management. An economic life analysis identifies optimal timing for facility
replacement or repair and prioritizes facilities for maintenance attention. The analysis assisted with
achieving the City’s goals for capital program development, which include sustainably meeting
required customer service levels, effectively managing risks, and minimizing the City’s costs of
ownership. The analysis also helped with defining M&O program recommendations and aids the
Utility’s continuing efforts to achieve a proactive maintenance environment. The economic life
assessment tool was a standalone, Excel-based application that required external data to be fed into
the model. Since 2009, the City has migrated to the use of Cartegraph, the City’s CMMS, for systems
operations. With the data in Cartegraph there is the opportunity to migrate the standalone economic
life assessment tool to reside within Cartegraph and run more regularly.
Evaluations completed for this Plan consisted of developing a system requirements specification for
integrating the pipe criticality model into the City’s asset management system, Cartegraph. Once the
pipe inventory is complete (updating GIS to include all required information), and the pipe criticality
model is implemented within Cartegraph, the economic life model can be rerun and used to inform
future R&R priorities. Currently, the economic life model includes only collection system piping, and
there is an opportunity to expand the model to include manholes and pump stations.
Further discussion of asset management, and why and how it can be further used to help manage
the sanitary sewer system, is provided in Section 9.3.
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Chapter 6
Maintenance and Operations
This chapter provides an overview of the organization and common procedures associated with the
ongoing maintenance and operation of the City of Auburn sewer utility system, with the primary
purpose of establishing a baseline understanding of the proactive and responsive maintenance
procedures performed by City staff. This baseline understanding is used herein to evaluate Utility
staffing, data collection and computerized record-keeping needs, and other Utility needs necessary
to continue to meet LOS goals.
The City sewer system, described in detail in Chapter 4, currently consists of approximately 200
miles of collection system piping, approximately 5,200 manholes, 15 sewer utility pump stations,
and 3 siphons and serves more than 18,000 Utility customers. Utility staff also maintain seven
stormwater pump stations and five sewer pump stations servicing facilities owned by other City
agencies.
6.1 Utility Responsibility and Authority
This section provides an overview of the Utility organization and basic information related to Utility
staffing, training, and education.
6.1.1 Organizational Structure
The Utility is operated as a utility enterprise under the direction of the Community Development and
Public Works Department (CDPW) Director. CDPW is responsible for planning, design, construction,
operation, maintenance, quality control, and management of the sewer system. The City has a
mayor-council form of government; therefore, the CDPW Director reports to the Mayor. The Mayor
and City Council provide oversight for the implementation of policies, planning, and management for
the Utility.
The Engineering Services Division (Engineering) within CDPW is the lead group for comprehensive
sewer system planning; development of a CIP; and the design, construction, and inspection of
projects related to the sewer system. The City Engineer/Assistant Director of Engineering oversees
Engineering and reports directly to the CDPW Director.
The Storm/Sewer Manager oversees the Utility, and is responsible for its day-to-day maintenance
and operation. The Assistant Director of Public Works Operations, who reports to the CDPW Director,
oversees the Storm/Sewer Manager, who in turn oversees 10 employees including a field supervisor.
The location of the Utility within the overall CDPW organizational structure is shown in Figure 6-1.
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Figure 6-1. City of Auburn Department of Community Development and Public Works organizational chart
6.1.2 Staffing Level
The Utility currently employs nine full-time M&O field staff plus a manager and a field supervisor, who
perform administrative duties. This chapter does not include an evaluation of Utility management,
including regulatory compliance, planning, and coordination with other City departments. The
position titles and primary functions of the full-time M&O field staff working within the Sewer Division
are shown in Table 6-1.
Table 6-1. Sewer Utility M&O Field Personnel
Position Primary function(s)
Sewer/Storm manager Utility administrative duties
Sewer field supervisor Supervision of field staff
Sewer specialist Two full-time staff dedicated to pump station inspection and maintenance
Maintenance worker II Six full-time staff dedicated to field inspection and maintenance
Maintenance worker I One full-time staff dedicated to field inspection and maintenance
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6.1.3 Level of Service
The Utility operates in accordance with the LOS criteria outlined in Chapter 3, and internally adopted
goals integral to meeting those levels. These goals are generally based on the current staffing level
and tasks deemed most critical to the City and its residents. However, the existing staffing
requirements discussed in Section 6.6 include near-term goals, which may not be met by existing
active staff.
6.1.4 Operator Training and Education
The City recognizes the value of having a knowledgeable and well-trained staff operating the Utility,
and encourages employees to obtain the highest level of training available. At this time, the State of
Washington does not require certification for sewer maintenance operators but the City would
support any effort to establish certification for these positions. Seminars, conferences (specifically
the annual Washington Wastewater Collection Personnel Association [WWCPA] conference), and
college coursework have become tools to advance knowledge for maintenance staff with subjects
covered including safety, pumps, generators, forklift training, confined space, first aid, CPR, and
electric and electronic fundamentals.
Many M&O staff are specialized in specific job functions, which can promote expertise through
specialization but also has the potential to limit the ability of the Utility to absorb absences due to
vacation, sickness, retirement, and termination. To mitigate this limitation, the City has broadened
the scope of the Utility’s education system by initiating a formal cross-training program.
6.2 Routine Operations
Routine M&O activities for the Utility can be divided into functional groups by facility type, as
described in the following sections.
6.2.1 Pump Station Maintenance
Utility staff are responsible for maintenance of 27 pump stations, including 15 sewer utility stations
(see Chapter 4), 7 stormwater utility stations, and 5 pump stations serving facilities owned by other
City agencies, at the Auburn Golf Course, Auburn City Hall, Auburn Justice Center, Isaac Evans Park,
and Auburn Valley Humane Society. M&O activities include scheduled weekly and monthly
equipment and grounds maintenance as well as emergency generator testing and maintenance.
Pump station maintenance is a full-time commitment for two Utility staff, including a maintenance
worker and a sewer specialist.
6.2.1.1 Weekly Activities
Weekly pump station inspections are intended as a quick check to ensure proper operation and
performance, and to identify potential non-emergency concerns to be addressed during scheduled
monthly maintenance. Equipment maintenance schedules are based upon manufacturers’
recommendations for preventive equipment maintenance. Depending on the site and time of year,
grounds maintenance may also be performed weekly or postponed for monthly maintenance.
Weekly pump station maintenance activities include the following tasks:
• perform a general visual inspection of grounds and pump station structure or vault
• check equipment for abnormal vibrations
• check lubrication of all pumping equipment
• check and clean, as needed, seal filters
• check ultrasonic level sensor
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• check pump run times
• bleed lines of moisture
• inspect/exercise control valves
• check wet well for debris
• manually run pump and observe wet well level
Weekly inspection activities are intended to be completed in less than 1 hour for each pump station.
6.2.1.2 Monthly Activities
Monthly pump station maintenance activities incorporate weekly activities while allowing more time
for detailed maintenance and to address any concerns identified during previous weekly
maintenance. Monthly maintenance can be particularly important for older pump stations, where
equipment and facilities require more attention. Engine-generators are also inspected and tested on
a monthly basis.
Monthly pump station maintenance activities include the following tasks:
• inspect and test engine-generators (see below)
• inspect pump station mechanical bypass pumping
• flush sump pit and manually run sump pump
• clean pump station interior and, at a minimum, wipe down control panels and pumps, and wash
down/disinfect floor
• inspect fall restraint system
• spot-check control system and telemetry alarms
Duration of monthly inspection activities varies widely depending upon the age/condition of the
pump station and observations made during previous weekly inspections. On average, monthly
inspections are assumed to be completed within 2 hours at each pump station.
6.2.1.3 Generator Testing and Maintenance
City M&O staff perform limited maintenance on emergency generators serving sewer and stormwater
pump stations, primarily to verify the generator’s ability to perform in an emergency. Emergency
generators are exercised and fuel levels are evaluated during monthly maintenance activities.
Private contracting services are used for detailed generator maintenance. It is recommended that
detailed generator maintenance be performed annually.
Permanent generators are located at all 15 Utility-owned sewer pump stations. Three of the
stormwater pump stations are equipped with permanent engine-generators. During a power outage,
pump stations at City Hall and the Justice Center are run via generators that serve the building.
Those two generators are not maintained by the Utility. Pump stations not served by permanent
generators can be operated using portable generators owned and maintained by CDPW.
6.2.1.4 Wet Well Cleaning and Inspection
Wet well cleaning is performed as needed, but on average is necessary twice annually. Some pump
stations in service areas with a noted high amount of FOG accumulation require cleaning at a higher
frequency (see Section 6.3).
Although the City owns a vactor truck, pump station wet well cleaning is performed by a private
contractor that can more efficiently clean multiple facilities in a single day because of a larger vactor
truck volume. During cleaning, wet wells are drained and the inside is cleaned with high-pressure
water. Accumulated FOG and sludge/sediments are suctioned from the wet well by the contractor
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and transported to a disposal facility. During cleaning, City staff inspect all floats, sensors, and other
hardware while the wet well is drained and they also visually inspect the wet well structure for
damage.
6.2.2 Collection System Maintenance
Utility staff are responsible for maintenance of approximately 200 miles of collection system piping
and approximately 5,200 manholes. M&O activities include pipe cleaning/jetting, closed-circuit
television (CCTV) inspection, and manhole maintenance.
6.2.2.1 Manhole Maintenance
Manhole maintenance includes initial inspection and potential follow-up cleaning and/or repair.
Inspection is performed by one person using utility mapping to locate the targeted facilities. The
inspection includes the following:
• visual confirmation of proper flow conveyance
• assessment of solids buildup in the manhole
• evaluation of structural damage or wear and the integrity/condition of manhole covers and
ladder rungs
Follow-up cleaning and maintenance work orders are generated based upon the results of initial
inspection and typically include a two-person crew. Based upon recent maintenance history, it is
estimated that approximately 1 in 10 manhole inspections leads to further cleaning. The City
estimates that a total of 50 manholes per year require some repair.
6.2.2.2 Sewer Pipeline Cleaning and CCTV Inspection
Cleaning and inspection of the sewer system is performed using City-owned vactor/jet truck and
CCTV equipment. Cleaning and CCTV inspection are typically performed in tandem from manhole to
manhole by a two- or three-person crew3 for each task.
Jetting of sewer pipelines and subsequent vactor truck removal is the principal means of removing
debris, sludge, FOG, and obstructions from the sewer system. A hose with a special end fitting is
inserted into a pipe and high-pressure water (up to 2,500 pounds per square inch [psi]) is sent
through the hose. The high-pressure water exits the small hole at the tip of the nozzle, breaking down
and/or scouring obstructions. Debris is then removed via suction by the vactor truck equipment at
each manhole.
Following cleaning, CCTV inspection is performed to identify structural defects and potential pipeline
leaks. Routine CCTV inspection of the sewer system is an essential component of the M&O program
as it can identify trouble spots before larger failures occur and can provide the City with accurate
information about the condition of the sewer collection system. Since the end of 2007, inspection
reports and digital video captured by the CCTV crews have been stored within the City’s computer
network (PIPELOGIX software). While the ability to edit information in PIPELOGIX is limited to licensed
machines, the PIPELOGIX reader is available for all City staff. Currently, the City does not have the
ability to transfer the data stored in PIPELOGIX, specifically a summary of pipe condition, to the more
comprehensive data stored within Cartegraph, the Utility CMMS software. A primary goal of the Utility
in the near future is to use the results of CCTV inspection to populate pipe conditions fields within
Cartegraph in order to provide a more accurate planning tool based upon the known condition of
wastewater system assets.
3 Although a three-person crew is assigned to these tasks, work may proceed with a two-person crew (at a slower rate) in
the case of employee absence. The staffing evaluation in Section 6.6 assumes a three-person crew for pipeline cleaning
and CCTV.
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The City’s goal is to clean and inspect all sewer collection pipes, using the NASSCO PACP, within the
system on a 5-year cycle 4. On average, a three-person crew can clean approximately 3,000 feet of
pipe per day or inspect approximately 1,500 feet of pipe per day.
6.2.3 Field Operations
In addition to the M&O activities discussed in Sections 6.2.1 and 6.2.2, the Utility typically maintains
a two-person field crew that performs a variety of other ongoing Utility functions. The Utility is also
available to assist other Public Works divisions such as Water, Stormwater, or Transportation during
manpower shortages or emergencies. Sewer staff perform liaison functions with Engineering and
construction inspections for new projects, repairs, or modification of existing lines.
Currently, the services for Utility locates are performed by two designated locators who are under the
supervision of the Water Division Manager.
Examples of field operations activities include:
• Repair: Sewer staff perform repair of minor pipe breaks/leaks and other system infrastructure.
• Engineering: Sewer staff often provide facility inspection services for Engineering projects and
support Engineering through visual observation in the field.
• Vehicle and equipment maintenance: The Utility maintains an extensive inventory of equipment
available to respond to problems or emergencies. The fleet is currently equipped with seven
trucks, one CCTV van, one sewer vactor/jet truck, and one emergency bypass pump. Each
component of this fleet is equipped with valve operators and traffic control equipment.
• Supply inventory: The Utility maintains an inventory of supplies and parts that are available for
use in responding to emergency situations as well as normal Utility operations. Supplies and
parts are tracked in an inventory control system that allows easy identification of available
materials.
It is difficult to quantify the field tasks performed by Utility staff in terms of equivalent staff. Many of
these tasks are performed outside of a regular maintenance schedule. The evaluation of existing
staffing requirements in Section 6.6 assumes that a two-person field operations crew is maintained
for a majority (0.75) of working days, or 1.5 FTE.
6.3 Fats, Oils, and Grease Reduction Program
FOG can cause major blockages in sewer pipes when not properly disposed of at the source. When
FOG enters a sewer, it cools, solidifies, and sticks to the interior of pipes. FOG buildup increases over
time, potentially causing backups in the sewer system and operational concerns within pump
stations. Engineering currently employs a 0.25 FTE water resources technician to implement and
oversee a City FOG Reduction Program. The program focuses on regulation of food service
establishments (FSEs) in order to minimize the amount of FOG entering the City sewer system.
The City currently monitors 170 FSEs within the service area, 76 of which are required to use grease
trap/interceptor pretreatment facilities before discharge to the sewer collection system. FSEs are
identified through the business licensing process, during which all FSEs are required to submit for
approval a FOG control plan per ACC Chapter 13.22. ACC also codifies requirements for installation
of pretreatment facilities (typically grease traps and interceptors), cleaning and maintenance, water
quality testing, and record-keeping. ACC does not have strong language tied to enforcement, nor
4 The frequency goal is specifically intended for all critical areas (serving critical facilities) or piping with a history of repair
or maintenance needs. A lower frequency, approximately every 7 years, for the remainder of the collection system would
not compromise Utility operations.
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does the City focus on penalties for noncompliance. It is informal City policy to work with FSEs on a
cooperative basis through outreach activities; however, refusal to comply with City requirements can
result in code enforcement action.
The 170 FSEs are grouped informally into 12 geographic areas. The City goal is to concentrate FOG
Reduction Program activities in one area per month, visiting or contacting most FSEs annually.
However, because of limited staffing for the program, inspection and education efforts have focused
on the highest-priority FSEs and areas with noted FOG issues. On average, only 3 of the 12 FSE
areas are inspected or targeted with mailings developed by the City to inform the public and FSEs of
FOG issues. In recent years, maintenance staff has noted, at various times, a high accumulation of
FOG at the Area 19, F Street, Rainier Ridge, Terrace View, and Riverside pump stations. Following
those observations, staff has prioritized those areas for inspections and educational outreach. It is
noteworthy that only one of these stations receives some of its wastewater from FSEs and most
serve areas with high concentrations of multifamily and rental housing. Sewer staff indicate that they
have observed improvements in the accumulation of FOG in the collection system and pump stations
following those efforts, but there is currently no system to quantify FOG reduction.
In addition to efforts to reduce the amount of FOG in the system, education and outreach efforts
include discouraging the flushing of cleaning wipes that may be labeled “flushable,” but that do not
disperse in water. These items can clog sewer lines and get caught in pumps, increasing
maintenance efforts within both the City collection and conveyance system, and King County’s
treatment system.
6.4 Non-Routine and Emergency Operations
This section discusses unscheduled activities performed by sewer M&O staff, and provides a
response plan for emergency conditions. The intent of the routine inspection and maintenance
activities discussed in Sections 6.2 and 6.3 is to minimize, through proactive management of the
sewer facilities, the potential for conditions that could lead to emergencies.
6.4.1 Customer Service Requests
Customer service requests, such as a localized sewer backup complaint, trigger creation of a work
order to inspect the affected area or sewer facility and identify potential solutions. In some cases,
relatively simple solutions can alleviate the issue. However, other cases require coordination with
Engineering or other City departments. On average, City sewer staff respond to approximately 50
customer service/complaint-related work orders per year. The effort required to resolve complaints
varies considerably.
Good record-keeping can help in complaint resolution by ensuring that all relevant data are gathered
and by serving as a reminder to resolve the complaint and notify the complainant. When a complaint
is received, the following information should be recorded to the greatest extent possible:
• name and contact information of the person making the complaint
• brief description of the nature of the complaint
− if sewer overflow, include estimate of volume and duration of overflow
• time and date the complaint was received
• M&O staff assigned to respond
Following initial response, the complaint record is updated to include the results of inspections and
corrective actions taken, if any. If the complaint cannot be resolved internally within the Utility, the
complaint record should be forwarded to Engineering for further investigation. Notification of any
system investigation and/or action should be provided to the customer making the complaint.
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6.4.2 Emergency Response Program
The Utility, in conjunction with the other utility divisions, has prepared a Public Works Emergency
Response Manual as a guide on how to handle emergency situations. The manual is by no means all-
inclusive for every type of disaster; however, it is a valuable tool for dealing with many of the
emergency situations that municipalities face. Copies of the Emergency Response Manual are
available at the CDPW M&O Building, at the City Hall Annex with the City Engineer, and at Fire Station
33 with the fire chief.
The Emergency Response Manual is one element of the City’s Comprehensive Emergency
Management Plan. The primary objectives of the Comprehensive Emergency Management Plan are
to ensure public safety, restore essential services as quickly as possible, and provide assistance to
other areas as required. There is also a master response program for the entire City as documented
in the Emergency Operations Plan. The material in the Emergency Operations Plan provides guidance
for mitigation, preparedness, responsibilities, recovery operations, training, and community
education activities. Copies of the Emergency Operations Plan are located in each City department,
the Public Works M&O Building, and the Valley Regional Fire Authority (Station 31).
The Utility has implemented a standby program whereby one on-call employee is designated to be
the first to receive after-hours emergency calls. Most sewer system problems that occur outside
normal working hours are reported through the City’s 911 emergency response system. An
emergency call-out list is provided to the emergency operator in order to contact Utility staff in case
of an emergency. The primary responder to those after-hours calls is the on-call employee. Utility
M&O staff have been trained to respond to system emergencies. The contacted staff assesses the
situation, contacts additional staff as necessary, and then responds in accordance with established
emergency response procedures.
6.5 Communications, Data Collection, and Record-Keeping
This section describes the electronic communication, data collection, and record-keeping systems
used by Utility staff.
6.5.1 Telemetry and Pump Station Controls
The Utility uses a computerized system (SCADA) to monitor and operate, as necessary, the sewer and
storm pump stations from a centralized location. SCADA information from all sewer, storm, and water
facilities is routed via radio signals to the M&O control center located at 1305 C Street SW. The
control center monitors wet well levels at all of the sewer pump stations together with pump run
times and cycles.
Logic programming automates the sewer pump station operation via ultrasonic level detectors with
backup high and low float switches. The control center is configured to sound an alarm in the M&O
building if a recognized anomaly is detected. The alarm system is linked to an automatic telephone
dialer that will seek sewer personnel to investigate the anomaly in the event that the problem occurs
during non-working hours. All alarm and pump information is recorded within the computer that
functions as the control center.
The SCADA and telemetry systems were recently updated throughout the sewer system and added to
several previously unserved pump station locations. The completed project provides the City with up-
to-date technology and uniformity throughout the Utility.
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6.5.2 Data Collection and Record-Keeping
Data collection and record-keeping functions for the Utility are performed using Cartegraph, a Web-
based commercial software package provided by Cartegraph Inc. Cartegraph integrates GIS data
with Utility M&O records, providing managers with overview information about system and
operational performance, and field crews with information related to the condition and failure history
of specific wastewater facilities. The City currently uses Cartegraph to plan field staff activities (work
orders), record results of both routine and non-routine maintenance, and compare actual
maintenance efforts to City goals. The City recently upgraded the Cartegraph system and plans to
transition toward its use as an asset management tool, through which the City would optimize
staffing and capital resource planning.
In recent years, the City has made considerable progress in adding asset information to Cartegraph,
specifically GIS data, physical information related to size and material, and installation date.
However, to fully utilize the asset management function of Cartegraph, additional information related
to risk, asset criticality, and condition is also necessary. To assist the City’s transition to an asset
management program, the attributes listed below should be used within Cartegraph to define each
of the City sewer assets (manhole, pipe segment, pump, etc.).
6.5.2.1 Asset-Specific Attributes
The following asset-specific attributes are related to the asset and remain relatively unchanged over
time:
• Asset ID: The unique asset number that is used by all business systems to identify an asset.
• Location: Where the asset is located (GIS).
• In-service date: The date the asset was placed into service.
• Replacement cost: The cost to replace the asset and the year that the cost data were calculated.
• Useful life: The average life expectancy of the asset.
• Asset criticality: A value assigned to each asset that indicates how essential it is to maintaining a
defined LOS. Typically it is defined as a combined score based on the consequence of failure
and the likelihood of failure, as defined below:
− Consequence of failure: The social and economic cost if the asset fails
− Likelihood of failure (condition): The estimated time until the asset fails, usually based on
condition
• Asset class: A group of assets that share the same characteristics (e.g., manholes, pipe
segments). Asset class is used to estimate replacement costs and useful life of groups of assets.
• Nameplate information and asset specifications: Important information that is used to uniquely
describe an asset such as the manufacturer name, type of asset, serial number, size, material,
etc. This information is used for asset identification, replacement, and repair.
6.5.2.2 Maintenance and Operation Attributes
The following M&O attributes are captured as part of the operations, maintenance, and repair history
associated with each asset.
• Asset ID: Most work orders should be associated with one or more assets. The asset ID is used
to uniquely associate work with individual assets.
• Issue, cause, action: These codes are used to classify historical M&O activities associated with
corrective actions or unplanned maintenance.
− Issue: What is the problem observed in the field?
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− Cause: What is the underlying cause of the problem?
− Action: What was done to address the cause?
• Target hours and actual hours: Recording the estimated hours and actual hours to complete a
work order can help in determining efficiency, planning workloads, and assessing repair costs.
• Target start/stop date and actual dates: Recording the estimated and actual start and stop
dates for a work order can help in determining efficiency, planning workloads, and assessing
repair costs.
• Work order costs: Work order costs include labor, parts, materials, and equipment, and should
be accurately recorded for each work order.
• Work order type: Work order types are used to group and compare different types of work
activities. Typical work order types include:
− Capital improvement: Work associated with a capital improvement project
− Corrective maintenance: Work associated with an unplanned repair
− Preventive maintenance (PM): Work associated with a planned preventive maintenance
activity
− Predictive maintenance (PdM): Work associated with predictive measures (usually for critical
assets)
• Warranty information: Helps to determine assets that are under warranty and the warranty
maintenance requirements.
6.6 Existing Staffing Requirements
Existing staffing requirements for M&O activities as discussed in this chapter were compiled and
evaluated to determine staffing requirements needed to efficiently operate, maintain, repair, and
collect and report the information necessary to properly operate the sewer system. Table 6-2
evaluates the estimated time to conduct sewer system M&O tasks in the manner currently
performed. Calculated days for each M&O activity are for a single person performed over an 8-hour
“day.” Therefore, an activity that is performed quarterly and that requires 4 hours and two M&O staff
to complete would result in an annual requirement of 4 days.
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Table 6-2. Sewer System Maintenance and Operation Task Summary
Work activity FTE days required
annually Assumptions/City goal
Collection system maintenance
Manhole inspection 22 Inspect once every 4 years, total of 5,200 manholes. Perform 60
inspections per day with one-person crew.
Manhole cleaning 65 One cleaning is required for every 10 inspections. Two-person crew, 2
hours each.
Manhole repair 50 50 repairs per year. Two-person crew, 4 hours each.
Pipeline cleaning 210 City goal is 210,000 ft per year (entire system in 5 years). A three-person
crew can clean 3,000 ft of pipe per day.
CCTV inspection 420 City goal is 210,000 ft per year (entire system in 5 years). A three-person
crew can CCTV-inspect 1,500 ft of pipe per day.
Pump station maintenance
Weekly routine maintenance 263 27 pump stations weekly (52 per year). Two-person crew, 0.75 hour each.
Monthly routine maintenance 162 276 pump stations monthly (12 per year). Two-person crew, 2 hours each.
Wet well cleaning 27 27 pump stations, 2 per year. Two-person crew, 2 hours each.
Other sewer M&O activities
Field operations 330 Two-person field crew for 0.75 of working days (1.5 FTE).
Customer service
requests/complaints 50 50 requests per year. Two-person crew, 4 hours each.
Data entry 260 40 hours per week total.
Subtotal 1,859
Total 2,045 Assumes 10% unquantified work
Total number of working days
available per FTE 200 Based on 10-year average
Number of FTEs required 10.2 2,045 days required divided by 200 days per FTE year.
Current FTEs 9
Table 6-2 shows that the Utility is under-staffed with respect to meeting current City goals for M&O
activities. The analysis confirms the qualitative assessment of staffing adequacy provided by City
staff during workshop discussions. Based upon discussion with City staff, there are portions of the
collection system piping for which there is no CCTV record. Because of limited staff, areas of the
collection system have received higher priority due to frequent need for maintenance (older pipe in
poor condition), relatively flat slopes, or high concentrations of FOG. There will likely be a need for
additional staff to perform more frequent cleaning and CCTV inspection of the entire system and to
account for sewer system expansion with overall city growth. It is recommended that the City
consider hiring two new Utility staff to meet M&O activity goals.
6.7 Potential Improvement Opportunities and Capital Needs
The Utility has a positive track record for M&O, as evidenced by the limited need for non-routine
maintenance and few customer service requests/complaints. Routine facility cleaning, regular
inspections, experienced staff, and a well-planned sewer system contribute to that success.
However, the growing backlog for collection system maintenance (cleaning and CCTV) should be
addressed by the City by adding to the current M&O staff. An additional 2 FTE are required to achieve
current City proactive M&O goals (see Table 6-2).
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Based upon discussions with City staff and analysis of M&O activities discussed in this chapter, the
following improvement opportunities are available to the Utility. These opportunities are based on
improving existing services and improving work productivity:
• Continue to integrate asset management with existing Utility management software (CMMS and
GIS):
− Continue to add GIS attributes to known Utility assets.
− Perform and document condition assessments. Use defined criteria (such as leaks/cracks
observed, cleanliness, and other specific measures) and provide staff training to ensure
assessment consistency. Use NASSCO PACP-certified inspection programs to allow
integration of inspection results with Cartegraph.
− Over time, use the results of condition assessments to move toward risk-based maintenance
to best utilize staff resources. For example, consistently high assessment scores would
result in a lower risk or need for maintenance, allowing M&O staff to be diverted to more
essential activities.
• Complete inspection of inverted siphons (river crossings, see Section 4.2.4) for which there is no
record of pipe condition. The City does not have the equipment to inspect these facilities;
therefore, contract services will be required.
• Hire one permanent, full-time staff member for CMMS data entry, maintenance tracking, and
reporting. This staff member would support the City Sewer, Stormwater, and Water utilities and
would be a liaison with the City Innovation and Technology (IT) Division.
• Initiate a manhole ring and cover replacement project, targeting a specific percentage of system
assets per year. Results of PM indicate a general deterioration of manhole covers within the
system.
• Based on staff observations regarding the location of maintenance issues caused by FOG
accumulation, continue to manage FSE’s compliance with FOG requirements at its current level,
and increase public education efforts to minimize FOG discharge in residential areas.
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Chapter 7
Recommended Plan
This chapter discusses recommended capital projects for the City of Auburn’s sewer system. The
capital projects necessary to meet and maintain the City’s LOS through the 20-year planning period
(2016–35) are presented as a CIP.
This Plan contains time frames, which are the intended framework for future funding decisions and
within which future actions and decisions are intended to occur. However, these time frames are
estimates, and depending on factors involved in the processing of applications and project work, and
availability of funding, the timing may change from the included time frames. The framework does
not represent actual commitments by the City, which may depend on funding resources available.
The identification of projects is an ongoing effort requiring periodic evaluation. This CIP list was
developed based on incorporating the City’s Capital Facilities Program (CFP), identification of
equipment limitations within the M&O group, and identification of areas of improvement.
7.1 Capital Improvement Program
The CIP focuses on addressing known problems in a manner identifying cost-effective solutions that
incorporate the risks associated with underperforming facilities and the uncertainty inherent in
engineering calculations/model simulations. A flow chart depicting the process of CIP development
is shown in Figure 7-1.
Figure 7-1. CIP development flow chart
The CIP places emphasis on projects identified for implementation between 2016 and 2021, which
constitutes the 6-year planning period for utility capital funding requirements and staffing needs.
This period provides a realistic outer limit for accurately forecasting the annual cycle of utility
projects and priorities. This Plan also includes a 20-year CIP that examines long-term capital
requirements, such as the replacement of infrastructure as it exceeds its useful life. All projects in
the CIP are consistent with the LOS described in Section 3 of this document.
Evaluate
system
Define policies and
criteria
Plan capital
projects
Evaluate
costs and
benefits
Complete CIP
Not
Acceptable
Acceptable
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7.1.1 Project Priority
All projects in the CIP have been designated a priority for implementation. Priority was assigned as
one of three designations. Projects in the top tier, or highest priority, are designated priority 1;
projects in the middle tier are designated priority 2; and projects with the lowest priority relative to
the other projects are considered priority 3. The priority levels are based on how the proposed
project impacts LOS. The project descriptions below include the designated priority.
7.1.2 Project Cost
Estimated costs for each project are included in the CIP descriptions below. The costs are planning-
level estimates. Actual costs will depend on various factors at the time of design and construction
including labor and material costs. Estimated costs include an allowance for engineering,
administration, legal fees, construction costs, sales tax, and construction supervision. Permitting and
land, easement, and/or right-of-way acquisitions are not included in the cost estimate. The costs
estimates are in 2014 dollars. CIP projects 1 and 2 are part of the City’s Capital Facilities Program,
where the City developed the costs for these projects.
7.2 Project Summary
The CIP projects mainly consist of ongoing and programmatic capital improvements. Ongoing
projects include projects identified through previous studies. The City has previously allocated
funding to each of these projects, which are currently in various stages of execution. These projects
must continue to receive funding under the CIP until completion and have been included in this
document to provide a complete picture of the program. Programmatic projects are included in the
CIP to provide funding for maintaining and/or improving the LOS. These projects do not address a
problem at a specific location, but allocate budget for addressing LOS goals citywide. As discussed in
Chapter 5, the system hydraulic analysis indicated no need for capacity-related capital projects in the
6-year or 20-year planning period. The next Plan update, scheduled for 2020 and repeating every 6
years, has been included as a cost in Table 7-1; however, there is not a description for the project.
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Table 7-1. Annual Project Cost Summary for 6-Year and 20-Year CIP
Project
number Project name Priority 2016 2017 2018 2019 2020 2021 2022–35 Project Cost
CIP
allocations
(repair/
replacement)
CIP
allocations
(upgrade/
expansion)
1
Sanitary Sewer Repair
and
Replacement/System
Improvements
1 $1,873,000 $300,000 $1,500,000 $300,000 $1,500,000 $300,000 $12,600,000 $18,373,000 100% 0%
2 Street Utility
Improvements 1 $200,000 $200,000 $200,000 $200,000 $200,000 $200,000 $2,800,000 $4,000,000 100% 0%
3 Vactor Decant Facility 1 $150,000 $0 $0 $0 $0 $0 $0 $150,000 0% 100%
4
Sewer Pump Station
Replacement/
Improvement 1 $0 $141,000 $500,000 $168,000 $900,000 $141,000 $2,850,000 $4,700,000 100% 20%
5 Siphon Assessment 1 $0 $524,000 $0 $0 $0 $0 $524,000 $1,048,000 100% 0%
6 Pump Station Condition
Assessment 1 $187,000 $0 $0 $0 $0 $0 $187,000 $374,000 100% 0%
7 Manhole Ring and
Cover Replacement 2 $80,000 $80,000 $80,000 $80,000 $80,000 $80,000 $1,120,000 $1,600,000 100% 0%
8 Cleaning and Inspection
of Large-Diameter Pipe 2 $0 $400,000 $0 $0 $0 $0 $400,000 $800,000 100% 0%
9 Inflow and Infiltration
Study 3 $0 $135,200 $135,200 $135,200 $135,200 $135,200 $0 $676,000 100% 0%
10 Plan Update 1 $0 $0 $0 $0 $350,000 $0 $700,000 $1,050,000 50% 50%
Total cost for priority 1 projects $2,410,000 $1,165,000 $2,200,000 $668,000 $2,950,000 $641,000 $19,661,000 $29,695,000
Total cost for priority 2 projects $80,000 $480,000 $80,000 $80,000 $80,000 $80,000 $1,520,000 $2,400,000
Total cost for priority 3 projects $0 $135,200 $135,200 $135,200 $135,200 $135,200 $0 $676,000
Total CIP cost $2,490,000 $1,780,200 $2,415,200 $883,200 $3,165,200 $856,200 $21,181,000 $32,771,000
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Project number 1
Project name Sanitary Sewer Repair and Replacement/System Improvements
Location Throughout the SSSA
Priority 1
Schedule Ongoing, alternating a large project every other year
Problem summary As infrastructure ages, failures begin to appear, causing LOS issues
Description
This project is R&R of existing sewer lines, manholes, public side sewers, and other facilities. These
assets will be identified through closed-circuit television (CCTV) inspection and routine cleaning and
monitoring. This particular program includes proposed projects that do not have an approved Project
Management Plan, or are not associated primarily with the Save Our Streets (SOS) or other
transportation improvements. Anticipated projects include biannual, standalone, R&R projects for sewer
lines that are broken, misaligned, “bellied,” or otherwise require an inordinate amount of maintenance
effort or present a risk of backup or trench failure, and facilities that generate consistent odor
complaints. Improvements identified through this program may be completed as components of larger
projects to gain efficiencies in project costs. Additionally, system improvements that enhance the ability
to maintain service are included here. It is anticipated that the Economic Life model, once developed and
integrated with Cartegraph, will be the source behind planning the R&R program. This project is planned
to occur during both the 6- and 20-year CIPs.
Recommended
predesign
refinements
Refine list as additional information becomes available
Cost estimate Costs developed by the City and carried over from the Capital Facilities Plan
2016 $1,873,000
2017 $300,000
2018 $1,500,000
2019 $300,000
2020 $1,500,000
2021 $300,000
2022–35 $12,600,000
Project Cost $18,373,000
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Project number 2
Project name Street Utility Improvements
Location Throughout the SSSA
Priority 1
Schedule Ongoing
Problem summary As infrastructure ages, failures begin to appear, causing LOS issues.
Description
This project is R&R of existing sewer lines, manholes, and public side sewers located within the project
limits of City arterial transportation projects and within the SOS program. Coordinating sanitary sewer
utility projects with arterial transportation projects can lower the unit cost of pipe replacement by
eliminating the pavement restoration component of the sewer project’s costs. This project is planned to
occur during both the 6- and 20-year CIPs.
Recommended
predesign
refinements
Refine list as additional information becomes available
Cost estimate Costs developed by the City and carried over from the Capital Facilities Plan
2016 $200,000
2017 $200,000
2018 $200,000
2019 $200,000
2020 $200,000
2021 $200,000
2022–35 $2,800,000
Project cost $4,000,000
Project number 3
Project name Vactor Decant Study
Location N/A
Priority 1
Schedule 2016
Problem summary Hauling saturated wastes to County landfills costs operating budget and takes away from crew time,
reducing other work they could be completing.
Description
Currently the City hauls vactored sewage waste to the County landfill on a biweekly basis. The sewage
sludge is considerably wet, thus City funds are paying for the disposal of water. A study is needed to
assess the City’s vactor disposal method and identify a cost-effective alternative to the status quo.
Possible recommendations may include maintaining current operations, constructing a gravity decant
facility, incorporating special equipment into the vactor truck to increase decanting ability, or purchasing
specialized dewatering machinery.
Recommended
predesign
refinements
Identify current City practices, how much sewage waste is vactored, how much liquid can be decanted
from the vactor truck, and the volume and percent water of the waste disposed at the County landfill.
Cost estimate
Engineering services for study $100,000
Subtotal line-item costs $100,000
Project contingency (30% of all above costs) $30,000
Subtotal inspection costs $130,000
Administration (15% of costs) $20,000
Project cost $150,000
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Project number 4
Project name Sewer Pump Station Replacement/Improvements
Location Throughout the SSSA
Priority 1
Schedule 2017–22
Problem summary
The 8th Street Pump Station, Valley Meadows Pump Station, and 22nd Street Pump Station have been
identified as needing to be renovated, replaced, and/or relocated based on condition, safety concerns,
and to accommodate growth. This CIP provides for a programmatic program to renovate or replace these
pump stations on a bi-annual basis. The anticipated order for modification/replacement is:
1. 8th Street Pump Station
2. Valley Meadows Pump Station
3. 22nd Street Pump Station
It is anticipated that additional stations will require significant improvements and/or replacement within
the 6 – 20 year planning horizon as well. The sum of the estimated cost for the first three pump stations
is used as a placeholder for project value. Following the results of the systematic pump station
evaluation study scheduled for 2016 (CIP project 6, Pump Station Inspections), the sequence or
identification of pump stations requiring R&R, and detailed scope of improvements for each of these
stations will be developed.
Description This project will renovate or replace the three currently identified pump stations within the 6-year CIP and
allocates money for R&R of unknown pump stations in the 6- to 20-year CIP.
Recommended
predesign
refinements
The Valley Meadows Pump Station is identified as a possible candidate for relocation to allow for future
sewer expansion. The need for relocation should be assessed and planned for prior to 2019. The costs
below for all pump stations do not include provisions for new gravity or force main piping. The costs also
assume that the existing generators on site will be reused and that no additional land or site
improvements are required.
Cost estimate 1. 8th Street Pump Station (2017/2018)
Package pump station $300,000
Project contingency (50% of all above costs) $150,000
Washington State and King County sales taxes (9.5% of all above construction costs) $43,000
Subtotal construction costs $493,000
Administration, engineering design, and permitting (30% of costs) $148,000
Subtotal $641,000
2. Valley Meadows Pump Station (2019/2020)
Package pump station $300,000
Project contingency (50% of all above costs) $150,000
Washington State and King County sales taxes (9.5% of all above construction costs) $43,000
Subtotal construction costs $493,000
Administration, engineering design, and permitting (30% of costs) $148,000
Subtotal $641,000
3. 22nd Street Pump Station (2021/2022)
Package pump station $500,000
Project contingency (50% of all above costs) $250,000
Washington State and King County sales taxes (9.5% of all above construction costs) $72,000
Subtotal construction costs $822,000
Administration, engineering design, and permitting (30% of costs) $246,000
Subtotal $1,068,000
Project cost $2,350,000
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Project number 5
Project name Siphon Assessment
Location Green River crossing near 26th Street NE; Green River crossing over 8th Street NE Bridge; Railroad
crossing near intersection of 6th St. NW and H St. NW
Priority 1
Schedule 2017, positioned in an off year of CIP 1, repeated in 10 years, 2027 or as initial inspection warrants
Problem summary Currently, the City does not have the required equipment to complete inspections of the three siphons
located within its collection system. Their condition is unknown.
Description
This project would inspect each siphon to determine its condition and help set future inspection/cleaning
protocols. The siphons would be inspected prior to cleaning to determine what their in situ condition is,
then if required the lines would be cleaned and re-inspected. Based on the debris level and condition of
the pipes, future activities can be planned. Repeat in 10 years. For cost efficiencies, it is assumed that
all three sites would be completed under one contract. This project is planned to occur during both the 6-
and 20-year CIPs.
Recommended
predesign
refinements
Determine flow rates required for bypass pumping/trucking. Verify the assumption that the Green River
crossing at 26th Street NE can be diverted to each barrel without the need for additional bypass
pumping.
Cost estimate Green River crossing via inverted siphon at 26th Street NE: 488 feet of 8" and 12" HDPE
Initial CCTV $2,500
Cleaning $2,000
Post-cleaning CCTV $2,500
Subtotal $7,000
Green River crossing via 8th Street NE bridge: 1,191 feet of 14" CIP
Traffic control $75,000
Bypass pumping $80,000
Initial CCTV $6,000
Cleaning $4,800
Post-cleaning CCTV $6,000
Subtotal $171,800
Railroad crossing adjacent to H and 6th streets: 287 feet of 18" unknown
Traffic control $20,000
Bypass pumping (trucking) $80,000
Initial CCTV $1,500
Cleaning $1,200
Post-cleaning CCTV $1,500
Subtotal $104,200
Subtotal line-item costs $283,000
Project contingency (30% of all above costs) $85,000
Washington State and King County sales taxes (9.5% of all above construction costs) $35,000
Subtotal construction costs $403,000
Administration, engineering design, and permitting (30% of costs) $121,000
Project cost $524,000
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Project number 6
Project name Pump Station Condition Assessment
Location Throughout the SSSA
Priority 1
Schedule 2016 and 2026
Problem summary
The City last completed a pump station condition assessment in 2007. The pump stations have
continued to age, regulations/codes have changed, and the City’s expectations of the pump stations
have changed over time. To adequately plan for future pump station investments, re-inspection is
required.
Description
The assessment will evaluate the apparent physical condition of existing stations and equipment. The
purpose of the assessment is to predict future serviceability and anticipated longevity for development of
future CIPs.
Pump stations must meet the adopted LOS in a safe and reliable manner. Stations must meet current
code conditions, which may differ from those that existed when the stations were originally built. The
assessment would identify requirements necessary to meet the City’s LOS, requirements necessary for
the health and safety of staff and the public, and suggestions that might increase reliability or reduce cost
of operations or maintenance.
Equipment checklists will be prepared for mechanical/hydraulic and electrical/control systems, site visits
to all stations will be made, as-built information and M&O manuals will be reviewed, and M&O personnel
will be asked about known issues at each location. Station operation will be observed, but no detailed
physical testing of equipment, wiring, controls, or structures will be included. To stay up to date on pump
station needs, it is recommended to repeat the inspection within the 20-year CIP.
Recommended
predesign
refinements
None
Cost estimate
Engineering services for condition assessment $125,000
Subtotal line-item costs $125,000
Project contingency (30% of all above costs) $38,000
Subtotal inspection costs $163,000
Administration (15% of costs) $24,000
Project cost $187,000
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Project number 7
Project name Manhole Ring and Cover Replacement
Location Throughout the SSSA
Priority 2
Schedule Ongoing
Problem summary According to M&O staff, there are failing frame and covers on sewer manholes. While the rest of the
manholes are in acceptable condition, the frames and covers need to be replaced.
Description
This project would establish an ongoing CIP to provide funds for continued replacement of frames and
covers. The cost for this effort is based on historical, all-inclusive spending from previous City of Auburn
work. This project is planned to occur during both the 6- and 20-year CIPs.
Recommended
predesign
refinements
None
Cost estimate
Frame and cover replacement $80,000
Subtotal line-item costs $80,000
Project contingency (0% of all above costs) $0
Washington State and King County sales taxes (9.5% of all above construction costs) Included
Subtotal construction costs $80,000
Administration, engineering design, and permitting (0% of costs) $0
Project cost $80,000
Project number 8
Project name Cleaning and Inspection of Large-Diameter Pipe
Location Throughout the SSSA
Priority 2
Schedule 2017, positioned in an off year of CIP 1, repeated in 10 years, 2027 or as initial inspection warrants.
Problem summary According to M&O staff, they are not equipped to efficiently clean pipe larger than 18 inches in diameter.
Description
This project would clean and internally inspect all pipe owned by the City that is larger than 18 inches in
diameter. This is approximately 39,300 feet, ranging in diameter from 20 inches up to 36 inches. This
project is planned to occur during both the 6- and 20-year CIPs.
Recommended
predesign
refinements
Review existing CCTV inspection information to see if any of the large-diameter pipe has been inspected
and determine if it needs cleaning.
Cost estimate
Cleaning $75,000
CCTV $82,000
Disposal $10,000
Traffic control $20,000
Subtotal line-item costs $187,000
Project contingency (50% of all above costs) $94,000
Washington State and King County sales taxes (9.5% of all above construction costs) $27,000
Subtotal construction costs $308,000
Administration, engineering design, and permitting (30% of costs) $92,000
Project cost $400,000
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Project number 9
Project name Inflow and Infiltration Study
Location Throughout the SSSA
Priority 3
Schedule Begin 5-year study in 2017
Problem summary
I/I does not appear to be an issue based on capacity. However, little to no work has been done to
actually try and quantify actual I/I rates. This project would assess the City SSSA to determine I/I values.
Excessive localized I/I can also be an indicator of poor sewer main and side sewer condition.
Description This project would monitor flow in the collection system over 5 years. These data will then be used in the
next Comprehensive Sewer Plan for modeling purposes and I/I assessment.
Recommended
predesign
refinements
Analyze existing flow metering and hydraulic model to develop a flow monitoring plan.
Cost estimate
Flow monitoring (four flow meters and two rain gauges for 6 months per year) $365,000
Subtotal line-item costs $365,000
Project contingency (30% of all above costs) $110,000
Washington State and King County sales taxes (9.5% of all above construction costs) $45,000
Subtotal construction costs $520,000
Administration, engineering design, and permitting (30% of costs) $156,000
Project cost $676,000
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Chapter 8
Finance
The objective of the financial plan is to identify the total cost of providing sewer service and to
provide a financial program that allows the Utility to remain financially viable during execution of the
identified CIP. This viability analysis considers the historical financial condition of the Utility, the
sufficiency of Utility revenues to meet current and future financial and policy obligations, and the
financial impact of executing the CIP. Furthermore, the plan provides a review of the Utility’s rate
structure with respect to customer affordability.
8.1 Past Financial Performance
This section includes a historical (2008–13) summary of financial performance as reported by the
City of Auburn on the statement of revenues, expenses, and changes in net position and the
statement of net position, specific to the Utility.
8.1.1 Statement of Revenues, Expenses, and Changes in Net Position
Table 8-1 shows a consolidated statement of revenues, expenses, and changes in net position for
2008–13.
8.1.1.1 Findings and Trends
Operating income (including depreciation expense) has been negative over the entire 6-year
historical period. Operating losses grew from a loss of nearly $556,000 in 2008 to a maximum loss
of $2.3 million in 2011. However, operating income improved significantly in 2012, resulting in a net
loss of only $460,000 and $260,000 in 2012 and 2013, respectively. Depreciation is a non-cash
expenditure, so even though operating income has been negative in every year, cash flow was
positive in most years during the 6-year period.
A few key financial ratios are discussed below. Unless otherwise noted, the stated benchmarks are
based on industry standards:
• M&O coverage ratio (operating revenues including depreciation divided by operating expenses):
− Benchmark: A ratio of 1.0 or higher is a desirable result, indicative of sufficient revenues to
meet cash operating expenses as well as to cover depreciation expense.
− Results: Increased from 0.96 in 2008 to 0.99 in 2013, which is a positive trend.
• Operating ratio (total operating expenses excluding depreciation divided by total operating
revenues):
− Benchmark: A ratio greater than 90 percent indicates there is little room for new debt
service and capital replacement without additional rate increases. A ratio greater than
100 percent indicates that cash operating expenses exceed operating revenues and is
indicative of an unsustainable financial condition.
− Results: Decreased from 95 percent in 2008 to 93 percent in 2013, which is a positive
trend overall. However, the operating ratio was at or above 100 percent from 2009 to 2011.
• Debt service coverage ratio (operating and interest revenues less M&O expenses excluding
depreciation, divided by total annual debt service):
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− Benchmark: There are two forms of debt service coverage; one applies to debt service from
revenue bonds only, and the other applies to debt service on total debt, including state
loans. Revenue bonds typically have a legal minimum coverage requirement of 1.25. State
loans usually do not carry a minimum coverage requirement; however, based on industry
standards, it is recommended that debt service coverage on total debt be at least 1.0. To be
conservative, this review of financial statements looks at coverage on total debt.
− Results: Coverage was below industry and City benchmarks from 2009 to 2011, but
increased to 2.4 or above in 2012 and 2013, which is a very favorable trend.
Table 8-1. City of Auburn Statement of Revenues, Expenses and Changes in Fund Net Position
2008 2009 2010 2011 2012 2013
OPERATING REVENUES:
Charges for services $13,601,390 $14,902,464 $15,968,231 $16,667,149 $18,585,288 $21,711,948
Other Operating Revenue 997 102 272 - - -
Total Operating Revenues 13,602,387 14,902,566 15,968,503 16,667,149 18,585,288 21,711,948
OPERATING EXPENSES:
Operations and Maintenance 10,071,648 12,215,275 12,666,971 14,177,079 13,841,985 16,005,927
Administration 1,774,962 2,106,258 1,992,048 1,916,148 1,956,954 2,139,329
Depreciation/Amortization 1,282,599 1,390,660 1,372,282 1,603,210 1,746,409 1,886,057
Other Operating Expenses 1,029,045 1,221,815 1,283,759 1,311,789 1,499,459 1,940,915
Total Operating Expenses 14,158,254 16,934,008 17,315,060 19,008,226 19,044,807 21,972,228
OPERATING INCOME (LOSS) (555,867) (2,031,442) (1,346,557) (2,341,077) (459,519) (260,280)
NON OPERATING REVENUE
(EXPENSES)
Interest Revenue 426,168 137,796 45,053 20,756 32,756 20,442
Other Non-Operating Revenue - 19,820 504,300 843,646 111,224 180,381
Interest Expense (20,807) (21,255) (314,931) (156,566) (102,869) (253,574)
Other Non-Operating Expenses (2,177) (2,874) - (1,069) (1,069) (4,782)
Total Non-Operating Revenue
(expenses) 403,184 133,487 234,422 706,767 40,042 (57,533)
INCOME(LOSS) BEFORE
CONTRIBUTIONS AND TRANSFERS (152,683) (1,897,955) (1,112,135) (1,634,310) (419,477) (317,813)
CAPITAL CONTRIBUTIONS 7,095,833 592,376 4,406,132 7,329,252 1,974,964 3,255,766
TRANSFERS IN - 89,425 - - - -
TRANSFERS OUT (50,000) (50,000) (55,960) (50,000) (50,000) (50,000)
Changes in Net Position 6,893,150 (1,266,154) 3,238,037 5,644,942 1,505,487 2,887,953
Net Position, January 1, as
Previously Reported 58,764,032 65,657,182 64,391,028 67,629,065 73,274,007 74,779,494
Change in Accounting Principle (19,250)
Net Position, January 1, as Restated
74,760,244
Net Position, December 31 $65,657,182 $64,391,028 $67,629,065 $73,274,007 $74,779,494 $77,648,197
8.1.2 Statement of Net Position
Table 8-2 shows the consolidated statement of net position for 2008–13.
8.1.2.1 Findings and Trends
This statement shows that the City of Auburn’s net position increased from $65.7 million to
$77.6 million over the 2008–13 time period. This represents an 18 percent increase over the 6-year
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period. Cash and cash equivalents have grown 13 percent over this period, increasing from $11.3
million in 2008 to $12.8 million in 2013.
Non-current assets, which represent resources required for use or consumption beyond 1 year, have
increased from $54.6 million in 2008 to $71.5 million in 2013. Most of this growth in long-term
assets comes from a $23.4 million increase in improvements other than buildings.
A few key financial ratios are discussed below. Unless otherwise noted, the stated benchmarks are
based on industry standards.
Liquidity
• Current ratio (unrestricted current assets divided by current liabilities):
− Benchmark: A ratio of 2.0 or higher is considered good in terms of healthy liquidity. The
current ratio is a measure of short-term financial strength and answers an important
question: Are current assets able to cover expected current liabilities in the coming year?
− Results: From 2008 through 2013, this ratio has ranged from 4.8 to 25.4, each year well
above the recommended benchmark. The ratio was 25.4 in 2008, but decreased to 4.8 in
2009 as a result of an increase in current payables and loans payable as well as a decrease
in cash and cash equivalents. The ratio has ranged from 7.4 to 8.8 from 2010 to 2013.
Efficiency
• Accounts receivable collection period (customer receivables on balance sheet x 365 days then
divided by annual sales):
− Benchmark: Generally, less than 30 days is considered very good.
− Results: Decreased from 44 days in 2008 to 40 days in 2013, which is a positive trend.
Capital
• Debt to net capital assets ratio (total debt divided by capital assets net of accumulated
depreciation):
− Benchmark: For utilities, having a capital structure of at least 40 percent equity and less
than 60 percent debt is considered a healthy capital structure, with adequate future
borrowing capacity and a manageable debt service burden. The City’s capital structure policy
is even more conservative: 50 percent debt and 50 percent equity.
− Results: Increased from 8 percent debt/92 percent equity in 2008 to 12 percent debt/
88 percent equity in 2013. This is well within both the industry and City maximum
benchmark thresholds.
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Table 8-2. City of Auburn Statement of Net Position
2008 2009 2010 2011 2012 2013
ASSETS
Current Assets
Cash and Cash Equivalents $11,337,351 $8,901,147 $8,178,622 $7,855,899 $10,049,455 $12,778,843
Investments 2,003,750 2,023,437 2,009,920 1,996,562 - -
Restricted Cash
Bond Payments 296,268 307,299 448,108 447,210
Customer Deposits 18,471 18,471 16,835 44,053 91,391 95,451
Other 738,017 737,890 4,382,960 1,831,850 514,590 516,972
Customer Accounts 1,636,060 1,739,422 2,025,836 1,971,772 2,108,360 2,375,137
Other Receivables 37,069 14,217 14,217 100 - -
Due From Other Governmental Units - - - 15,721 - -
Inventories 8,968 8,259 7,414 7,147 6,479 7,009
Total Current Assets 15,779,686 13,442,843 16,932,072 14,030,403 13,218,383 16,220,622
Non Current Assets
Long Term Contracts and Notes 1,073,400 1,050,900 1,028,400 983,400 938,400 825,900
Capital Assets
Land 1,654,958 1,654,958 1,695,023 1,695,023 1,695,023 1,695,023
Buildings and Equipment 1,131,744 1,131,744 1,140,893 1,171,259 1,171,259 1,235,992
Improvements Other Than Buildings 65,113,774 65,667,532 73,495,451 80,984,120 87,643,097 88,561,822
Construction in Progress 846,620 4,056,688 2,104,633 4,570,300 1,694,876 2,372,710
Less: Accumulated Depreciation (15,200,016) (16,590,677) (17,962,959) (19,566,169) (21,312,578) (23,198,636)
Total Capital Assets ( Net of A/D) 53,547,080 55,920,245 60,473,041 68,854,533 70,891,677 70,666,911
Total Non-Current Assets 54,620,480 56,971,145 61,501,441 69,837,933 71,830,077 71,492,811
Total Assets 70,400,166 70,413,988 78,433,513 83,868,336 85,048,460 87,713,433
LIABILITIES
Current Liabilities
Current Payables 424,743 1,921,254 473,770 501,844 423,363 627,749
Current Deposits 18,471 18,471 16,835 - - -
Loans Payable-Current - 236,791 288,262 288,262 288,262 288,262
Employee Leave Benefits-Current 69,282 72,952 73,325 90,346 97,848 108,988
Revenue Bonds Payable-Current - - - - 141,162 144,845
General Obligation Bonds Payable-Current - - - - - -
Accrued Interest 13,183 14,205 309,091 317,569 316,496 311,195
Deposits - - - 44,054 91,391 95,450
Total Current Liabilities 525,679 2,263,673 1,161,283 1,242,075 1,358,522 1,576,489
Non Current Liabilities
Unearned Revenue 162,203 162,203 162,203 162,203 162,203 162,203
Employee Leave Benefits 8,545 24,110 38,336 41,011 33,948 32,500
Loans Payable 4,046,557 3,572,974 4,108,241 3,819,979 3,531,717 3,243,456
Revenue Bonds Payable - - 5,334,385 5,329,062 5,182,577 5,050,589
General Obligation Bonds Payable - - - - - -
Total Non Current Liabilities 4,217,305 3,759,287 9,643,165 9,352,255 8,910,445 8,488,748
Total Liabilities 4,742,984 6,022,960 10,804,448 10,594,330 10,268,967 10,065,237
NET POSITION
Invested In Capital Assets, Net of Related Debt 53,547,080 52,110,480 54,700,611 60,824,782 61,837,121 61,939,759
Restricted for:
Debt Service
720,768 731,596 873,536 964,182
Capital Projects 21,398 737,890
-
Unrestricted 12,088,704 11,542,658 12,207,685 11,717,628 12,068,836 14,744,255
Total Net Position $65,657,182 $64,391,028 $67,629,064 $73,274,006 $74,779,493 $77,648,196
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8.1.3 Outstanding Debt Principal
Table 8-3 outlines the City’s outstanding debt principal as of the end of 2013.
The City of Auburn has one outstanding revenue bond and two outstanding Public Works Trust Fund
loans. The total outstanding principal on these loans is $8.6 million.
Table 8-3. City of Auburn Outstanding Debt Principal
Debt Description Principal Outstanding Maturity Year
2010 CIP Revenue Bond $5,086,760 2030
PW-06-962-003 $2,345,433 2026
PW-04-691-001 $1,186,284 2024
Total $8,618,477
8.2 Available Capital Funding Resources
Feasible long-term capital funding strategies should be defined to ensure that adequate resources
are available to fund the CIP identified in this Plan. In addition to the Utility’s resources such as
accumulated cash reserves, capital revenues, bond proceeds, and system development charges
(SDCs), capital needs can also be met from outside sources such as grants, low-interest loans, and
bond financing. The following is a summary of internal Utility resources, government programs and
resources, and public debt financing.
8.2.1 Internal Utility Resources
Utility resources appropriate for funding capital needs include accumulated cash in the capital
“account,” bond proceeds, and other capital revenues, such as SDCs. Capital-related revenues are
discussed below.
8.2.1.1 Utility Funds and Cash Reserves
User charges (rates) paid by the Utility’s customers are the primary funding source for all Utility
activities. The rates cover total annual costs associated with operating and maintaining the sewer
system. Rates can pay for capital improvement projects in two ways: either paying for debt service or
directly paying for capital projects. Although funding the capital costs directly through rates does not
result in the additional interest expense associated with issuing debt, this approach can cause large
and/or volatile rate increases.
8.2.1.2 System Development Charges
An SDC, as provided for by RCW 35.92.025, refers to a one-time charge imposed on new customers
as a condition of connection to the utility system. The purpose of the SDC is twofold: (1) to promote
equity between new and existing customers, and (2) to provide a source of revenue to fund capital
projects. Equity is served by providing a vehicle for new customers to share the cost of infrastructure
investment. SDC revenues provide a source of cash flow used to support utility capital needs;
revenue can be used only to fund utility capital projects or to pay debt service incurred to finance
those projects.
In the absence of an SDC, growth-related capital costs would be borne in large part by existing
customers. In addition, the net investment in the Utility already collected from existing customers,
whether through rates, charges, and/or assessments, would be diluted by the addition of new
customers, effectively subsidizing new customers with prior customers’ payments. To establish
equity, an SDC should recover a proportionate share of the existing and future infrastructure costs
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from a new customer. From a financial perspective, a new customer should become financially
equivalent to an existing customer by paying the SDC.
Table 8-4 summarizes the City’s current SDC schedule.
Table 8-4. City of Auburn Current System Development Charge Schedule
Type Sewer SDC
Single Family Parcel $850 Per Parcel
Other Parcels $850 Per RCE
Note: A Residential Customer Equivalent (RCE) shall be as defined
by the King County Department of Natural Resources.
A recent SDC study has been completed and the City Council is currently evaluating the updated
charges.
8.2.1.3 Local Facilities Charge
While an SDC is the manner in which new customers pay their share of general facilities costs, local
facilities funding is used to pay the cost of local facilities that connect each property to the system
infrastructure. Local facilities funding is often overlooked in a rate forecast because it is funded up
front either by connecting customers or developers, or through an assessment to properties—but
never from rates. Although these funding mechanisms do not provide a capital revenue source
toward funding CIP costs, a discussion of these charges is included in this chapter because of their
impact on new customers.
Several mechanisms can be considered toward funding local facilities. One of the following scenarios
typically occurs:
• the utility charges a connection fee based on the cost of the local facilities (under the same
authority as the SDC)
• a developer funds extension of the system to its development and turns those facilities over to
the utility (contributed capital)
• a local assessment is set up called a utility local improvement district (ULID), which collects tax
revenue from benefited properties
A local facilities charge (LFC) is a variation of the SDC authorized through RCW 35.92.025. It is a city-
imposed charge to recover the cost related to service extension to local properties. Often called a
front-footage charge and imposed on the basis of footage of main “fronting” a particular property, it
is usually implemented as a reimbursement mechanism to a city for the cost of a local facility that
directly serves a property. It is a form of connection charge and, as such, can accumulate up to 10
years of interest. It typically applies to instances where no developer-installed facilities are needed
through developer extension because of the prior existence of available mains already serving the
developing property.
The developer extension is a requirement that a developer install onsite and sometimes offsite
improvements as a condition of extending service. These are in addition to the SDC required and
must be built to city standards. The city is authorized to enter into developer extension agreements
under RCW 35.91.020. Part of the agreement between the city and the developer for the developer
to extend service might include a latecomer agreement, resulting in a latecomer charge to new
connections to the developer extension.
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Latecomer charges are a variation of developer extensions whereby a new customer connecting to a
developer-installed improvement makes a payment to the city based on their share of the
developer’s cost (RCW 35.91.020). The city passes this on to the developer that installed the
facilities. This is part of the developer extension process, and defines the allocation of costs and
records latecomer obligations on the title of affected properties. No interest is allowed, and the
reimbursement agreement is in effect for a period of 20 years, unless a longer duration is approved
by the city.
ULID is another mechanism for funding infrastructure that assesses benefited properties based on
the special benefit received by the construction of specific facilities (RCW 35.43.042). Most often
used for local facilities, some ULIDs also recover related general facilities costs. Substantial legal
and procedural requirements can make this process relatively expensive, and there are mechanisms
by which a ULID can be rejected by a majority of property ownership within the assessment district
boundary.
8.2.2 Government Programs and Resources
This section outlines government programs and resources potentially available for financing.
8.2.2.1 Grants and Low-Cost Loans Overview
Historically, federal and state grant programs were available to local utilities for capital funding
assistance. However, these assistance programs have been mostly eliminated, substantially reduced
in scope and amount, or replaced by loan programs. Remaining miscellaneous grant programs are
generally lightly funded and heavily subscribed. Nonetheless, even the benefit of low-interest loans
makes the effort of applying worthwhile. Grants and low-cost loans for Washington State utilities are
available from various Washington State departments. There are many grant and loan programs that
the City might be eligible for, described in greater detail below.
8.2.2.2 Department of Commerce
A September 2014 document from the Washington State Department of Commerce summarizes
various loan and grant programs available (“Summary of Some Grant and Loan Programs for
Drinking Water and Wastewater Projects,” found at http://www.commerce.wa.gov/Documents/9-2-
14_multi-program_funding_program_summary.pdf). A few of those programs are described below.
Community Economic Revitalization Board (CERB). CERB, a division of the Washington State
Department of Commerce, primarily offers low-cost loans; grants are made available only to the
extent that a loan is not reasonably possible. The CERB targets public facility funding for
economically disadvantaged communities, specifically for job creation and retention. Priority criteria
include the unemployment rates, number of jobs created and/or retained, wage rates, projected
private investment, and estimated state and local revenues generated by the project. According to its
website, “CERB funds a variety of projects that create jobs including (but not limited to) domestic
and industrial water, storm and sewer projects, telecommunications and port facilities.” Eligible
applicants include cities, towns, port districts, special purpose districts, federally recognized Indian
tribes, and municipal corporations.
Funding details for the 2013–15 Program are as follows per the Washington Commerce website:
“$9 million was appropriated to CERB for the 2013-2015 Biennium. By state law, CERB must award
75 percent of this funding to projects in rural counties. The Board has also allocated $2,182,500 to
be available for construction and planning grants on a first-come, first-served basis.” (See Table 8-5)
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Table 8-5. Funding Programs
Program Funding Limitations
Committed Private Sector Partner
Construction • $2 million per project load award limit
• Up to $300,000 or 50% of total award, whichever is less, may be grant funds.
• 20% cash match required (minimum, percent of total project cost)
Prospective Development
Construction
Available to rural communities only.
• $2 million per project load award limit
• Up to $300,000 or 50% of total award, whichever is less, may be grant funds.
• 20% cash match required (minimum, percent of total project cost)
Planning/Economic Feasibility
Studies • $50,000 grant per project award limit
• 25% cash match required (minimum, percent of total project cost)
Further details are available at:
• http://www.commerce.wa.gov/commissions/CommunityEconomicRevitalizationBoard/
• http://www.commerce.wa.gov/Documents/2013-15_Policies.pdf
• http://www.commerce.wa.gov/commissions/CommunityEconomicRevitalizationBoard/Pages/CE
RB-Traditional-Programs.aspx
Public Works Board (PWB) Financial Assistance. The PWB’s overarching goal is to provide
community access to financial and technical resources that help sustain local infrastructure. Cities,
towns, counties, and special-purpose districts are eligible to receive financial assistance for
qualifying projects. When funding is available, the following tools are accessible:
• Construction Loan Program (http://www.pwb.wa.gov/financial-
assistance/Construction/Pages/default.aspx):
− Funding cycle: Per the PWB website, the governor’s proposed 2015–17 budget offers $69.7
million for 19 projects.
− Program description: Low-interest loans for local governments to finance public
infrastructure construction and rehabilitation. Eligible projects must improve public health
and safety, respond to environmental issues, promote economic development, or upgrade
system performance.
− Terms: For non-distressed communities, a term of 5 years or less has an interest rate of
1.28 percent and a term from 6 to 20 years has an interest rate of 2.55 percent.
• Pre-Construction Loan Program (http://www.pwb.wa.gov/financial-assistance/Pre-
Construction/Pages/default.aspx):
− Funding cycle: No funding has been allocated to the pre-construction loan program for the
2013–15 biennium.
− Program description: Local governments may apply for low-interest loans to finance pre-
construction activities to prepare a project for construction.
− Terms: Terms are limited to a 5-year repayment period (the loan term may be converted to
20 years once the project has secured construction funding) with a 1 percent interest rate.
• Emergency Loan Program (http://www.pwb.wa.gov/financial-assistance/Emergency-
Loan/Pages/default.aspx):
− Funding cycle: No funding has been allocated to the Emergency Loan Program for the
2013–15 biennium.
− Program description: The Emergency Loan Program provides funding to address public-
works emergencies, thereby helping to provide immediate restoration of critical public-works
services and facilities.
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− Terms: Funds are limited to $500,000 per jurisdiction per biennium, and come with a 20-
year term (or the life of the project), and a 3 percent interest rate. No local match is
required.
Further general resources are available at:
• http://www.pwb.wa.gov/financial-assistance/Pages/default.aspx
• http://www.pwb.wa.gov/Documents/FINAL-MASTER-GUIDELINES.pdf
• http://www.commerce.wa.gov/Documents/9-2-14_multi-
program_funding_program_summary.pdf
8.2.2.3 Department of Ecology: Integrated Water Quality Funding Program
This year, Ecology received 227 applications requesting more than $352 million in financial
assistance. Ecology is proposing grant and loan funding for 165 projects totaling approximately
$229 million.
• State Water Pollution Control Revolving Fund and Centennial Clean Water Program
− Design projects associated with publicly owned wastewater and stormwater facilities. The
integrated program also funds planning and implementation of nonpoint source pollution
control activities. Terms for State fiscal year 2016 include either 2.4 percent interest for a
6–20 year term or 1.2 percent for 5-year term loans. Forgivable loan principal terms are
available for distressed communities.
− Further general resources are available
at: http://www.ecy.wa.gov/programs/wq/funding/cycles/FY2016/index.html
8.2.3 Public Debt Financing
This section describes potentially available public debt financing tools.
8.2.3.1 General Obligation Bonds
General obligation (GO) bonds are bonds secured by the full faith and credit of the issuing agency,
committing all available tax and revenue resources to debt repayment. With this high level of
commitment, GO bonds have relatively low interest rates and few financial restrictions. However, the
authority to issue GO bonds is restricted in terms of the amount and use of the funds, as defined by
Washington constitution and statute. Specifically, the amount of debt that can be issued is linked to
assessed valuation.
RCW 39.36.020 states:
(ii) Counties, cities, and towns are limited to an indebtedness amount not exceeding
one and one-half percent of the value of the taxable property in such counties, cities,
or towns without the assent of three-fifths of the voters therein voting at an election
held for that purpose.
(b) In cases requiring such assent counties, cities, towns, and public hospital districts
are limited to a total indebtedness of two and one-half percent of the value of the
taxable property therein.
While bonding capacity can limit availability of GO bonds for utility purposes, these can sometimes
play a valuable role in project financing. A rate savings may be realized through two avenues: the
lower interest rate and related bond costs, and the extension of repayment obligation to all tax-
paying properties (not just developed properties) through the authorization of an ad valorem property
tax levy.
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8.2.3.2 Revenue Bonds
Revenue bonds are commonly used to fund utility capital improvements. The debt is secured by the
revenues of the issuing utility and the debt obligation does not extend to the city’s other revenue
sources. With this limited commitment, revenue bonds typically bear higher interest rates than GO
bonds and also require security conditions related to the maintenance of dedicated reserves (a bond
reserve) and financial performance (added bond debt service coverage). The City agrees to satisfy
these requirements by ordinance as a condition of bond sale.
Revenue bonds can be issued in Washington without a public vote. There is no bonding limit, except
perhaps the practical limit of the utility’s ability to generate sufficient revenue to repay the debt and
provide coverage. In some cases, poor credit might make issuing bonds problematic.
8.2.4 Capital Resource Funding Summary
An ideal funding strategy would include the use of grants and low-cost loans when debt issuance is
required. However, these resources are very limited and competitive in nature and do not provide a
reliable source of funding for planning purposes. It is recommended that the City pursue these
funding avenues but assume bond financing to meet needs above the Utility’s available cash
resources. GO bonds may be useful for special circumstances, but because bonding capacity limits
are most often reserved for other City (non-Utility) purposes, revenue bonds are a more secure
financing mechanism for Utility needs. The Capital Financing Strategy developed to fund the updated
CIP follows the funding priority below:
1. Available grant funds and/or developer contributions
2. Interest earnings on allocated fund balances
3. Other miscellaneous capital resources
4. Annual revenue collections from SDCs
5. Annual transfers of rate-funded capital or excess cash (above minimum balance targets) from
operating accounts
6. Accumulated capital cash reserves
7. Revenue bond financing
The 20-year CIP is expected to be funded from cash reserves and non-debt capital revenues.
8.3 Financial Plan
The City of Auburn’s Sewer Utility is an enterprise fund that is responsible for funding all of its related
costs. It is not dependent upon general tax revenues or general fund resources. The primary source
of funding for the Utility is collections from sewer service charges. The City controls the LOS charges
by ordinance and, subject to statutory authority, can adjust user charges as needed to meet financial
objectives.
The financial plan can provide a qualified assurance of financial feasibility only if it considers the
“total system” costs of providing sewer service—both operating and capital. To meet these
objectives, the following elements are completed:
• Capital funding plan: The capital funding plan identifies the total CIP obligations for the planning
period 2014–35, although the capital plan identified in this Plan begins with 2016. The capital
funding plan defines a strategy for funding the CIP including an analysis of available resources
from rate revenues, existing reserves, SDCs, debt financing, and any special resources that may
be readily available (e.g., grants, developer contributions, etc.). The capital funding plan may
impact the financial plan through use of debt financing (resulting in annual debt service) and the
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assumed rate revenue resources available for capital funding. The capital funding plan is
discussed in Section 8.3.3.
• Financial forecast: This forecast identifies annual non-capital costs associated with the
operation, maintenance, and administration of the sewer system. Included in the financial plan
is a reserve analysis that forecasts cash flow and fund balance activity along with testing for
satisfaction of actual or recommended minimum fund balance policies. The financial plan
ultimately evaluates the sufficiency of Utility revenues in meeting all obligations, including
operating expenses, debt service, and reserve contributions, as well as any debt service
coverage requirements associated with long-term debt. The financial forecast analysis is
discussed in Section 8.4.
8.3.1 Utility Fund Structure
The City tracks the Utility’s revenues and expenditures in two funds: Fund 431 Sewer and Fund 433
Sewer Metro. The revenues and expenditures of both funds are included in the “combined” financial
forecast. Conceptually, Utility expenditures can be divided into three main types of costs: operating,
capital, and debt service. For modeling purposes, the “combined” sewer utility is split among three
“accounts” as is bulleted below: operating, capital, and debt reserves. Municipal utilities commonly
maintain separate operating, capital, and debt reserves. The initial allocation of the beginning fund
balance is discussed in Section 8.4.
• Operating: Serves as an operating account where operating revenues are deposited and
operating expenses are paid.
• Capital: Serves as a capital account where capital revenues are deposited and capital
expenditures are paid. Examples of capital revenues include SDCs, grant proceeds, debt
proceeds, and contributions from rates.
• Debt reserves: Serves as a restricted account set up to comply with debt covenants.
Splitting the funds into three separate “accounts” allows the City to apply the City’s and industry
standard reserve targets to each account. Minimum balance thresholds for these accounts are
discussed in the next section.
8.3.2 Financial Policies
A brief summary of the City’s adopted and or recommended financial policies follows below. Adopted
policies are based on the City’s “Process/Policies” section within the 2015–16 budget.
8.3.2.1 Reserve Policies
Utility reserves serve multiple functions; they can be used to address variability and timing of
expenditures and receipts; occasional disruptions in activities, costs, or revenues; and meeting utility
debt obligations. The collective use of individual reserves helps to limit the City’s exposure to
revenue shortfalls, meet long-term capital obligations, and reduce the potential for bond coverage
defaults.
• Operating reserve: An operating reserve is designed to provide a liquidity cushion; it protects the
utility from the risk of short-term variation in the timing of revenue collection or payment of
expenses. Like other types of reserves, operating reserves also serve another purpose: they help
to smooth rate increases over time. Target funding levels for an operating reserve are generally
expressed as a certain number of days of M&O expenses, with the minimum requirement varying
with the expected revenue volatility. Industry practice for utility operating reserves ranges from
30 days (8 percent) to 120 days (33 percent) of M&O expenses, with the lower end more
appropriate for utilities with stable revenue streams and the higher end of the range more
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appropriate for utilities with significant seasonal or consumption-based fluctuations (such as
most water utilities).
The City’s adopted policy states that the Sewer Utility’s target operating reserves should be
approximately 60 days (page 36, “Process/Policies”). This is the target used in the financial
forecast. Based on the City’s 2015 budgeted local expenditures (excluding depreciation and the
King County Metro remittance), a 60-day target equates to $1.1 million in 2015.
• Capital contingency reserve: A capital contingency reserve is an amount of cash set aside in
case of an emergency should a piece of equipment or a portion of the Utility’s infrastructure fail
unexpectedly. Additionally, the reserve could be used for other unanticipated capital needs
including capital project cost overruns. There are various approaches to identifying an
appropriate level for this reserve, such as (1) identifying a percentage of a utility system’s total
fixed assets, and (2) determining the cost of replacing highly critical assets or facilities. Following
common industry practice, this analysis assumes a minimum capital fund balance equal to 1
percent of the original cost of plant in service.
• Bond reserve: Bond covenants often establish reserve requirements as a means of protecting an
agency against the risk of nonpayment. This bond reserve can be funded with cash on hand, but
is more often funded at the time of borrowing as part of the bond principal. A reserve amount
equal to annual bonded debt service is targeted.
8.3.2.2 System Reinvestment Policies
The purpose of system reinvestment funding is to provide for the replacement of aging system
facilities to ensure sustainability of the system for ongoing operation. Each year, the Utility’s assets
lose value, and as they lose value they are moving toward eventual replacement. That accumulating
loss in value and future liability is typically measured for reporting purposes through annual
depreciation expense. This is based on the original cost of the asset divided by its anticipated useful
life. While this expense reflects the consumption of the existing asset and its original investment, the
replacement of that asset will likely cost much more, after factoring in inflation and construction
conditions. Therefore, the added annual replacement liability is often even greater than the annual
depreciation expense. It is prudent to establish a system reinvestment policy that attempts to
recover at least a portion of the annual depreciation expense.
The City’s adopted policy is to phase in system reinvestment funding over 10 years in 10 percent
increments beginning in 2012. To keep rates at their currently adopted levels through 2017, the
system reinvestment strategy for the financial plan begins in 2015 at 10 percent and increases by
10 percent per year until 100 percent of the target is funded.
8.3.2.3 Debt Policies
Bond covenants often establish a minimum debt coverage ratio as a means of protecting an agency
against the risk of nonpayment. The industry’s standard minimum coverage ratio is 1.25 times
annual revenue bond debt service. The City’s policy matches this industry standard.
The City also identifies another debt level related policy, which is to maintain a capital ratio of
50 percent debt to 50 percent equity. The industry standard is a maximum of 60 percent debt to
40 percent equity. The City’s capital ratio from the 2013 financial statement was well below that
threshold at approximately 12 percent debt to 88 percent equity. The forecast estimates that the
debt level will not exceed 12 percent debt in the 20-year planning period.
8.3.3 Capital Funding Plan
The CIP developed for this Plan contains 10 different projects valued at $33 million ($49 million
inflated) over the 2016–35 planning period. Capital expenditures for 2014 and 2015 are based on
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estimated and budgeted amounts, respectively. Costs are stated in 2014 dollars and are escalated
to the year of planned spending at an annual inflation rate of 3.5 percent per year.
Table 8-6 summarizes the expected annual capital expenditures.
Table 8-6. City of Auburn Sewer CIP
Year 2014 $ Inflated $
2014 $ 2,405,393 $ 2,405,393
2015 $ 2,300,934 $ 2,381,467
2016 $ 2,490,000 $ 2,667,350
2017 $ 1,780,200 $ 1,973,740
2018 $ 2,415,200 $ 2,771,498
2019 $ 883,200 $ 1,048,965
2020 $ 3,165,200 $ 3,890,839
2021 $ 856,200 $ 1,089,326
8 Year Total $ 16,296,327 $ 18,228,576
2022-2035 $ 21,181,000 $ 35,231,899
Grand Total $ 37,477,327 $ 53,460,475
A capital funding plan is developed to determine the total resources available to meet the CIP needs
and determine if new debt financing will be required. After allocating the estimated beginning 2015
fund balance first to the debt reserve and secondly to the operating reserve, nearly $9 million was
available for capital.
The SDC is projected to generate an average annual revenue stream of just over $630,000 through
2021. This is based on an assumed customer growth rate of 2 percent per year. The customer
growth percentage is drawn from a review of the previous 8 years of actual customer growth (2008–
15).
The SDC revenue projection assumes the current SDC of $850 plus an annual Construction Cost
Index adjustment starting in 2015. The City Council is currently reviewing an update of the SDCs.
A summary of the capital funding plan is summarized in Table 8-7. The analysis shows that the CIP
can be fully funded using cash reserves and non-debt capital revenue; no new debt is required.
Table 8-7. City of Auburn Capital Financing Plan
Year Capital
Expenditures
Capital
Expenditures
Inflated
Revenue Bond
Financing Cash Funding Total Financial
Resources
2014 $ 2,405,393 $ 2,405,393 $ - $ 2,405,393 $ 2,405,393
2015 2,300,934 2,381,467 - 2,381,467 2,381,467
2016 2,490,000 2,667,350 - 2,667,350 2,667,350
2017 1,780,200 1,973,740 - 1,973,740 1,973,740
2018 2,415,200 2,771,498 - 2,771,498 2,771,498
2019 883,200 1,048,965 - 1,048,965 1,048,965
2020 3,165,200 3,890,839 - 3,890,839 3,890,839
2021 856,200 1,089,326 - 1,089,326 1,089,326
8-Year Total $ 16,296,327 $ 18,228,576 $ - $ 18,228,576 $ 18,228,576
2022-2035 $ 21,181,000 $ 35,231,899 $ - $ 35,231,899 $ 35,231,899
Grand Total $ 37,477,327 $ 53,460,475 $ - $ 53,460,475 $ 53,460,475
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8.4 Financial Forecast
The financial forecast, or revenue requirement analysis, forecasts the amount of annual revenue
that needs to be generated by rates throughout the 2015–21 planning period. The analysis
incorporates operating revenues, M&O expenses, debt service payments, rate-funded capital needs,
and any other identified revenues or expenses related to utility operations, and determines the
sufficiency of the current level of rates. Revenue needs are also impacted by debt covenants
(typically applicable to revenue bonds) and specific fiscal policies and financial goals of the Utility.
For this analysis, two revenue sufficiency “tests” have been developed to reflect the financial goals
and constraints of the Utility: (1) cash needs must be met, and (2) debt coverage requirements must
be realized. In order to operate successfully with respect to these goals, both tests of revenue
sufficiency described below must be met.
8.4.1 Cash Flow Test
The cash flow test identifies all known cash requirements for the Utility in each year of the planning
period. Capital needs are identified and a capital funding strategy is established. This may include
the use of debt, cash reserves, outside assistance, and rate funding. Cash requirements to be
funded from rates are determined. Typically, these include M&O expenses, debt service payments,
system reinvestment funding or directly funded capital outlays, and any additions to specified
reserve balances. The total annual cash needs of the Utility are then compared to total operating
revenues (under current rates) to forecast annual revenue surpluses or shortfalls.
8.4.2 Coverage Test
The coverage test is based on a commitment made by the City when issuing revenue bonds. As a
security condition of issuance, the City is required per covenant to agree that the revenue bond debt
would have a higher priority for payment (a senior lien) compared to most other Utility expenditures;
the only outlays with a higher lien are M&O expenses. Debt service coverage is expressed as a
multiplier of the annual revenue bond debt service payment. For example, a 1.0 coverage factor
would imply that no additional cushion is required. A 1.25 coverage factor means revenues must be
sufficient to pay M&O expenses, annual revenue bond debt service payments, plus an additional 25
percent of annual revenue bond debt service payments. The excess cash flow derived from the
added coverage, if any, can be used for any Utility purpose, including funding capital projects. The
existing coverage requirement policy on the City’s outstanding revenue bonds is 1.25 times bond
debt. In determining the annual revenue requirement, both the cash and coverage sufficiency tests
must be met—the test with the greatest deficiency drives the level of needed rate increase in any
given year.
The financial forecast projects the amount of operating and capital expenditures to determine the
annual amount of revenue required. The objective of the financial forecast is to evaluate the
sufficiency of the current level of rates in meeting the total revenue requirements of the system. In
addition to annual operating costs, the revenue of the Utility must also meet debt covenant
requirements and minimum reserve level targets.
8.4.3 Financial Forecast
The financial forecast is developed from the City’s adopted 2015–16 biennial budget documents
along with other key factors and assumptions to develop a portrayal of the Utility’s annual financial
obligations. The forecast covers the 2015–21 planning period. The following is a list of the key
revenue and expense factors and assumptions used to develop the forecast.
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8.4.3.1 Revenue and Fund Balance Assumptions
The following revenue and fund balance assumptions are used to develop the forecast:
• Customer growth and demand: Based on a review of historical data from 2008 to 2015, annual
customer account growth has averaged approximately 2 percent. To be consistent with the
Water financial forecast, annual water use per account is projected to decline by 1 percent per
year until 2027. Because the residential rate structure is flat, the decline in usage in that class
would not affect rate revenues. Therefore, the 1 percent decline applies only to the variable
portion of sewer rate revenues. The net effect of 2 percent customer account growth and 1
percent decline in non-residential usage per account results in a composite rate revenue
increase of 1.5 percent per year.
• Adopted rate increases: The City has adopted annual rate increases through 2017 of roughly 2.5
percent, which are incorporated into the revenue figures within the forecast. The analysis shows
that through 2017, no additional rate increases are needed above the adopted levels.
• Miscellaneous revenues are conservatively assumed to stay at their currently budgeted levels.
Miscellaneous revenues include late penalties, sewer applications, etc. The Build America Bonds
(BAB) subsidy for the 2010 Revenue Bond is expected to gradually decline in proportion to the
annual decline in interest expense.
• Fund balances are based on the estimated beginning balance in 2015 for Fund 431. This
balance was allocated to the “accounts” using the following methodology:
1. Debt reserve: amount equal to highest annual bonded debt service on existing debt
2. Operating reserve: amount equal to the operating reserve target of 60 days
3. Capital reserve: remaining funds
The estimated beginning fund balance in 2015 was approximately $10.8 million, which is
enough to fully fund the debt reserve, and provide 60 days in the operating reserve, leaving
nearly $9 million to fund the capital reserve. The fund balance for Fund 433 (Sewer Metro
reserve) remains in that fund and is not used in this financial forecast.
8.4.3.2 Expenditures and Other Miscellaneous Assumptions
The following expenditures and other miscellaneous assumptions are used to develop the forecast:
• Interest earnings initially assume a rate of 0.09 percent applied to beginning-of-year cash
balances based on existing Local Government Investment Pool rates, phasing toward
0.25 percent over the long term.
• General operating expenses are escalated from the budgeted figures at 2.5 percent per year,
labor costs increase at 2.5 percent per year, and benefits at 5.5 percent per year.
• State taxes are calculated based on prevailing tax rates.
• Existing debt service schedules were provided by the City and include one existing revenue bond
issue as well as two Public Works Trust Fund loans. These obligations represent nearly
$728,000 in annual debt service as of 2015.
• The King County Metro charges were modeled as a “pass through”—revenues equal to
expenditures. Metro Service revenues were calculated using each year’s estimated number of
residential customer equivalents (RCEs) and the corresponding year’s monthly service charge.
Projected monthly charges were based on the County’s estimated rate schedule through 2020,
with inflationary adjustments assumed beyond 2020. Industrial surcharges were increased at
the same rate as the monthly service charge.
• This Plan identifies additional staffing needs above the 2015 and 2016 budgeted levels, which
total over $232,000 per year beginning in 2017:
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− Asset management specialist (0.5 FTE): salary and benefits of $46,000 per year (note: the
other 0.5 FTE is to be included within the City’s Storm Drainage Utility)
− Maintenance worker II (1 FTE): salary and benefits of $93,000 per year
− Maintenance worker II (1 FTE): salary and benefits of $93,000 per year
• The rate strategy focuses on the 2015–21 planning period. It is imperative that the City review
the proposed rates and rate assumptions annually to ensure that the rate projections developed
remain adequate. Any significant changes should be incorporated into the financial plan and
future rates should be adjusted as needed.
Table 8-8 summarizes the annual revenue requirement through 2021 based on the forecast of
revenues, expenditures, fund balances, fiscal policies, and capital funding.
In 2012, the City Council adopted annual rate increases of 2.5 percent in each of 2015, 2016, and
2017. The financial analysis shows that the adopted rates generate sufficient revenue to meet
operating expenses and the Utility policy goals as discussed herein for the 2015–17 period. Based
on the assumptions in the forecast, no incremental rate increases (above adopted amounts) are
needed through 2017.
Rate increases averaging about 3.3 percent per year are needed in 2018 and beyond to cover
projected M&O expenses, debt service payments, system reinvestment funding, and other stated
financial policy objectives.
Table 8-8. City of Auburn Financial Forecast
Revenue Requirements 2014 2015 2016 2017 2018 2019 2020 2021
Assuming Existing Rates:
Revenue
Local Rate Revenues $7,428,178 $7,729,650 $8,042,305 $8,366,484 $8,491,446 $8,618,273 $8,746,995 $8,877,640
Non-Rate Revenues + KC Metro Sewer 15,957,246 16,446,729 16,759,701 18,162,930 18,840,675 19,570,948 20,318,501 21,214,937
Total Revenue $23,385,424 $24,176,380 $24,802,006 $26,529,415 $27,332,121 $28,189,221 $29,065,496 $30,092,577
Expenses
Cash Operating Expenses $22,580,466 $23,073,590 $23,212,150 $25,130,173 $26,032,966 $26,998,699 $27,989,485 $29,146,421
Operating Expense per RCE* 739 735 786 805 826 846 868
Existing Debt Service 730,191 728,283 727,038 817,610 815,874 814,887 813,347 811,255
Debt Service per RCE* 23.3 23.0 25.6 25.2 24.9 24.6 24.3
New Debt Service - - - - - - - -
Rate-Funded System Reinvestment - 157,565 323,428 471,687 640,778 822,550 992,282 1,203,542
Additions to Operating Reserve - - - - 36,606 38,226 35,922 45,855
Total Expenses $23,310,657 $23,959,438 $24,262,616 $26,419,470 $27,526,224 $28,674,362 $29,831,036 $31,207,072
Cash Surplus / (Deficiency) - Before Rate Increases $74,767 $216,942 $539,389 $109,945 $(194,104) $(485,140) $(765,540) $(1,114,495)
Annual Rate Adjustment 0.00% 0.00% 0.00% 2.54% 3.62% 3.26% 3.85%
Cumulative Annual Rate Adjustment 0.00% 0.00% 0.00% 2.54% 6.25% 9.71% 13.94%
After Rate Increases:
Local Rate Revenues $7,428,178 $7,729,650 $8,042,305 $8,366,484 $8,706,904 $9,156,786 $9,596,757 $10,114,747
Cash Surplus / (Deficiency) - After Rate Increases 74,800 216,900 539,400 109,900 36,600 38,200 35,900 45,900
Debt Service Coverage - Revenue Bonds 5.82 6.72 7.98 6.42 6.72 7.18 7.63 8.20
Debt Service Coverage - All Debt 3.38 3.91 4.66 4.05 4.25 4.55 4.84 5.21
* Existing 31,230 RCE within the service area, as of June 2015. Assumed RCE growth is consistent with service area population growth
assumed for Hydraulic Capacity Analysis (Chapter 5 and Appendix B).
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The last two rows of Table 8-8 show the projected debt service coverage for both bonded debt and
total debt. Bonded debt service coverage—which legally cannot drop below 1.25—is projected to stay
at or above 5.8 throughout the life of the forecast. Debt service coverage for total debt (including
state loans) is recommended to be at least 1.0, and throughout the life of this forecast, it is
projected to stay at or above 3.4.
Table 8-8 includes projections of operating and debt service costs per RCE (see Section 2.3). Per
RCE operating costs are anticipated to increase within the planning period. The increase will occur
primarily due to the need for additional staff, which are needed for existing and anticipated new
system M&O tasks to maintain level of service as identified in previous chapters. Operating costs are
also anticipated to grow (Section 8.4.3.2) at a greater rate than assumed RCE growth. Per RCE debt
service is not projected to vary significantly within the planning period. No new debt service costs are
anticipated.
8.4.4 City Funds and Reserves Balances
Table 8-9 shows a summary of the projected ending City operating, capital, and debt reserve
balances through 2021. The operating reserve ends at 60 days of operating expenditures; the
capital reserve ends at $3.3 million, which is above the minimum target of $1.1 million; and the debt
reserve ends at $0.5 million, which is enough to cover 1 year of annual bonded debt service.
Table 8-9. City of Auburn Cash Balance Summary
Ending Reserves 2014 2015 2016 2017 2018 2019 2020 2021
Operating $1,139,255 $1,132,900 $1,101,349 $1,188,469 $1,225,076 $1,263,302 $1,299,223 $1,345,078
Capital 9,487,763 7,686,286 6,496,031 5,627,941 4,139,325 4,586,275 2,399,129 3,258,276
Debt 516,173 516,173 516,173 516,173 516,173 516,173 516,173 516,173
Total $11,143,190 $9,335,358 $8,113,553 $7,332,583 $5,880,574 $6,365,749 $4,214,525 $5,119,527
8.5 Existing Rate Structure and Projected Schedule
The City’s existing sewer rate structure for inside City customers is composed of two rate classes.
The residential rate schedule consists of a monthly base charge. The non-residential rate schedule
consists of both a monthly base charge and a volume charge based upon the amount of water used
as measured in 100-cubic-foot (ccf) increments above the initial allowance.
Residential sewer utility customers residing outside of the City’s political boundaries are assessed
charges based upon the inside City rate plus a 50 percent premium (ACC 13.06.360). Low-income
single-family residential customers are provided a 50 percent discount to the rates presented. To
qualify for a low-income discount, a customer must be 62 years old or older and meet low-income
guidelines as defined by the U.S. Department of Housing and Urban Development (ACC 13.24).
A recent detailed review of the City’s rate structure has been completed in the 2014 Retail Rate
Study. The review recommended increasing the volume charge while maintaining the current base
charge through 2017. This phases the existing rate structure toward a more standard definition of
7.5 ccf of implicit usage included in the monthly base charge.
Table 8-10 presents the City’s existing sewer rate schedule for each customer class under the
adopted rates through 2017 (no rate increases above adopted levels are necessary through 2017).
The table then incorporates necessary rate increases starting in 2018 and continuing through 2021.
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Table 8-10. City of Auburn Projected Local Rate Schedule
Monthly Rate Schedule Adopted Adopted Adopted Adopted Projected Projected Projected Projected
2014 2015 2016 2017 2018 2019 2020 2021
Annual: 0.0% 0.0% 0.0% 2.5% 3.6% 3.3% 3.8%
Cumulative: 0.0% 0.0% 0.0% 2.5% 6.2% 9.7% 13.9%
Residential
Base $23.12 $23.69 $24.29 $24.89 $25.52 $26.45 $27.31 $28.36
Non-Residential
Base (first 750 cf) $23.12 $23.69 $24.29 $24.89 $25.52 $26.45 $27.31 $28.36
Volume (additional 100 cf) $2.34 $2.39 $2.45 $2.52 $2.58 $2.68 $2.76 $2.87
Low Income Discount: 50%
Outside City Multiplier: 1.50
King County Metro Rates Not Included in Rate Forecast
Rate Increases shown in 2015, 2016, and 2017 reflect already-adopted annual increases of 2.5%
8.6 Affordability
The Washington State Department of Health and Public Works Board has historically used an
affordability index to prioritize low-cost loan awards. The typical threshold looks at whether a
system’s rates exceed 1.5 to 2.0 percent of the median household income for the demographic area.
As a result, if monthly bills are less than 1.5 percent of the median household income for the
demographic area, they are generally considered affordable.
According to City staff, the median household income for the city of Auburn in 2012 was $49,996.
This figure was inflated to $51,810 at 2014 levels assuming annual Consumer Price Index
adjustments. Table 8-11 presents the City’s estimated single-family sewer rate with the projected
rate increases for the forecast period. The affordability mark (monthly bill*12 ÷ median income)
averages 0.5 percent throughout the study period. As shown in Table 8-11, the City’s local sewer
rates remain well within the affordability range throughout the planning period. If the County’s
monthly charge is included in this calculation, the affordability mark averages 1.5 percent.
Table 8-11. City of Auburn Affordability Test
Year Inflation Median
HH Income
Projected
Monthly
Bill (Local
Only)
% of
Median
HH Income
2014 2.50% $51,810 $23.12 0.54%
2015 2.50% $53,106 $23.69 0.54%
2016 2.50% $54,433 $24.29 0.54%
2017 2.50% $55,794 $24.89 0.54%
2018 2.50% $57,189 $25.52 0.54%
2019 2.50% $58,619 $26.45 0.54%
2020 2.50% $60,084 $27.31 0.55%
2021 2.50% $61,586 $28.36 0.55%
Note: Monthly bill assumes residential local rate only.
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8.7 Conclusion
The financial analysis indicates that the adopted rates in 2015, 2016, and 2017 are sufficient to
meet the Utility financial obligations as presented herein. No additional rate increases are proposed
for 2015–17. Based on the forecast, required rate increases for 2018–21 average about 3.3
percent per year for a cumulative rate increase of 13.9 percent. The financial forecast shows that no
new debt is expected to be required to fund the identified capital program within this Plan.
This evaluation also finds that the local sewer rates with projected rate increases would remain
within the defined threshold of affordability.
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Chapter 9
Implementation Plan
Building upon the M&O activities outlined in Chapter 6 and the projects described in Chapter 7 , this
chapter presents a work plan for future Utility activities. Critical elements of the plan (e.g., CIP
implementation and criticality-based maintenance plans) are presented and a planning-level
schedule is provided to guide the Utility’s activities in the coming years.
For discussion, plan implementation is divided into two sections:
• presentation of the CIP for both 6- and 20-year time frames
• description of the steps forward in order to implement the activities described in this chapter.
Funding for these activities is described in a separate rate analysis study prepared in conjunction
with the overall Sewer Plan.
The timeline at the conclusion of this chapter shows the proposed implementation schedule.
9.1 6-Year and 20-Year CIP
The 6-year CIP contains projects identified by the City as requiring immediate action. The 6-year CIP
also contains general improvement projects allowing for annual R&R of facilities in the next 6 years.
Details regarding these projects are provided in Chapter 7. The 6-year CIP is shown in Table 9-1.
Table 9-1. Annual Project Cost Summary for 6-Year CIP (in millions of dollars)
Project
number Project name Priority 2016 2017 2018 2019 2020 2021
6-year
project
cost
1
Sanitary Sewer Repair and
Replacement/System
Improvements
1 $1.873 $0.300 $1.500 $0.300 $1.500 $0.300 $5.773
2 Street Utility Improvements 1 $0.200 $0.200 $0.200 $0.200 $0.200 $0.200 $1.200
3 Vactor Decant Study 1 $0.150 $0.000 $0.000 $0.000 $0.000 $0.000 $0.150
4 Sewer Pump Station
Replacement/Improvement 1 $0.000 $0.141 $0.500 $0.168 $0.900 $0.141 $1.850
5 Siphon Assessment 1 $0.000 $0.524 $0.000 $0.000 $0.000 $0.000 $0.524
6 Pump Station Condition
Assessment 1 $0.187 $0.000 $0.000 $0.000 $0.000 $0.000 $0.187
7 Manhole Ring and Cover
Replacement 2 $0.080 $0.080 $0.080 $0.080 $0.080 $0.080 $0.480
8 Cleaning and Inspection of
Large-Diameter Pipe 2 $0.000 $0.400 $0.000 $0.000 $0.000 $0.000 $0.400
9 Inflow and Infiltration Study 3 $0.000 $0.135 $0.135 $0.135 $0.135 $0.135 $0.676
10 Plan Update 1 $0.000 $0.000 $0.000 $0.000 $0.350 $0.000 $0.350
Total 6-year CIP cost for priority 1 projects $2.410 $1.165 $2.200 $0.668 $2.950 $0.641 $10.034
Total 6-year CIP cost for priority 2 projects $0.080 $0.480 $0.080 $0.080 $0.080 $0.080 $0.880
Total 6-year CIP cost for priority 3 projects $0.000 $0.135 $0.135 $0.135 $0.135 $0.135 $0.676
Total 6-year CIP cost $2.490 $1.780 $2.415 $0.883 $3.1615 $0.856 $11.590
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The CIP after the 6-year time period includes ongoing programmatic efforts to develop projects for
facility repair or replacement, including projects based on the City’s asset management tools. The
projects proposed for expenditures in the years 2022 to 2035, and an estimate of total CIP costs for
the 20-year period from 2014 through 2035, are shown in Table 9-2.
Table 9-2. Cost Summary for 20-Year CIP (in millions of dollars)
Project
number Project name Priority
Project costs for
2022–35
(2014 dollars)
1 Sanitary Sewer Repair and Replacement/System Improvements 1 $12.600
2 Street Utility Improvements 1 $2.800
3 Vactor Decant Study 1 $0.000
4 Sewer Pump Station Replacement/Improvement 1 $2.850
5 Siphon Assessment 1 $0.524
6 Pump Station Condition Assessment 1 $0.187
7 MH Ring and Cover Replacement 2 $1.120
8 Cleaning and Inspection of Large-Diameter Pipe 2 $0.400
9 Inflow and Infiltration Study 3 $0.000
10 Plan Update 1 $0.700
Total 2022–35 CIP cost for priority 1 projects $19.661
Total 2022–35 CIP cost for priority 2 projects $1.520
Total 2022–35 CIP cost for priority 3 projects $0.000
Total 2022–35 CIP cost $21.181
Total 20-year CIP cost $32.771
9.2 Monitoring
The King County flow monitoring and hydraulic modeling completed as part of this Sewer Plan
identified areas with high levels of I/I. As discussed in Section 5.2, the levels of I/I are not currently
problematic. However, it is recommended the City initiate the first steps of an I/I control program
(CIP project 9, Section 6.2) to proactively address potential concerns.
The first step in the program is to select flow metering locations. The budget of CIP project 9
assumed four flow monitors and two rain gauges for six months per year. The suggested initial flow
monitoring locations (manhole IDs) for year 1 of CIP project 9 are:
• 410-77
• 611-34
• 611-08
• 610-30
The hydraulic characteristics of exact locations should be examined prior to placement of flow
meters to maximize flow metering accuracy. The City should also use the recently upgraded SCADA
system to compile pump station pump run times and corresponding wet well levels.
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9.3 Asset Management and Maintenance and Operation
Asset management is a defined process for managing facilities and activities that will optimize the
life-cycle cost of Utility assets as well as to ensure that the Utility meets defined service levels. The
economic life model developed for the 2009 Comprehensive Sewer Plan and the recently developed
specification to migrate this model to Cartegraph is an example of a criticality-based approach to
deciding the optimal timing for repair or replacement of existing utility facilities. This method can also
be used for managing risks to the performance of sewers and force mains through maintenance
strategies. It is recommended that the City continue the business practice of asset management. To
help accomplish this, the City should fully populate its GIS information and implement the economic
life model within Cartegraph.
9.3.1 Collect Asset Data
The sanitary sewer system is a complex network of pipes and pump stations that collect and convey
wastewater produced within the city to the King County collection system. Not all system attributes
are currently included in the City’s CMMS database or GIS. Static attributes like material, size, and
installation dates can be updated anytime and the condition of each asset should be updated
following inspection. Figure 9-1 shows a map of the City’s sewer system (pipes) that have some of
the static attribute information missing and that need to be updated. Please note that an indication
that asset information is missing indicates that at least one particular attribute is not currently in the
CMMS database. Generally, that information exists elsewhere in City archives (as-built drawings,
etc.), but will be far more useful for managing the Utility’s assets when it has been compiled in the
CMMS.
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GreenRiver
LakeTapps
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Lea HillSewer Basin
South Hill Sewer Basin
Valley SewerBasin
King County
Pierce County
Auburn Way SouthSewer Basin
West HillSewerBasin
Pacific
Dogwood
Verdana
Safeway
Area 19
R Street
F Street
Auburn 40
Riverside8th Street
North Tapps
22nd Street
Auburn Jail
Terrace View
Rainier RidgePeasley Ridge
Lakeland Hills
Valley Meadows
Ellingson Road
Issac Evans Park
Auburn Golf Course
Auburn Justice Center
Auburn Valley Humane Society
COMPREHENSIVE SEWER PLAN
October 2015 FIGURE 9-1SANITARY SEWERSWITH MISSING ATTRIBUTEINFORMATION
3,500 0 3,500 7,000
Feet N
P:\Auburn\145308 Auburn Sewer Comp Plan Update\_GIS\Projects\Plan Figures\fig_4-2_ExistingWastewaterConveyanceSystem11x17.mxd
L E G E N D
Auburn Sewers with All Populated Information
Auburn Sewers with Missing Information
King County Sewers
Auburn Pump Station
King County Pump Station
Private Pump Station
City of Auburn Sewer Service Area
Major Roads
Street
County line
Streams/Rivers/Ponds
AUBURNSSAMASK
City of Auburn Comprehensive Sewer Plan Chapter 9
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9.3.2 Criticality
Criticality is determined based on the consequences of failure and the likelihood of the failure
occurring. Factors that impact criticality include the age of the asset, repair history of the asset, and
consequences, in terms of dollars, should a failure occur. Consequences of a system failure include
such considerations as whether a failure impacts a hospital or school as compared to a residence or
unoccupied property. Each asset is evaluated based on these likelihood and consequence factors
and a numerical weighting assigned. The combination of these factors results in the assignment of a
criticality value. Figure 9-2 depicts an example of assessing asset criticality values to a large
collection system. The data on the figure are not specific to the City’s sanitary sewer system.
Figure 9-2. Example of identifying asset criticality
The points shown above are sample data and do not represent a specific evaluation of Auburn's sanitary sewer system.
9.3.3 Defining Maintenance Strategies
As Figure 9-3 illustrates, an asset’s criticality can be used to determine the best maintenance
strategy for that asset. There are four general maintenance strategies based on the risk carried by
the asset and the specific maintenance strategy used should be assigned on an individual asset
basis to ensure that the appropriate actions are being taken.
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Figure 9-3. Maintenance strategies based on risk
High-risk assets are identified as having both a high likelihood of failure and a high consequence of
failure. These assets should be modified in order to mitigate this risk. Risk can be mitigated by
adding redundancy to reduce the consequence of failure or by selecting a more robust type of asset
that can perform the same function with a lower likelihood of failure. An example of this would be
adding a redundant pump to a pump station to reduce the consequence of any one pump failing, or
using a different type of pump to reduce the occurrence of clogs.
Moderate-risk assets have been separated into two regions: high-likelihood/low-consequence assets
and high-consequence/low-likelihood assets. The assets with a high likelihood of failure but a low
consequence of failure should receive time-based maintenance care. This maintenance strategy
includes preventive maintenance (PM) including inspection, calibration, oil changes, and tasks
recommended by the manufacturer or other best practices. Corrective maintenance should also be
conducted to address defects as they are revealed and the spare parts strategy should be prepared
for the high incidence of failures. The frequency of these maintenance activities is driven by the
economics of maintaining the asset; the cost of maintaining the asset should be in proportion with
the cost of replacing the asset in order to optimize the life-cycle cost of asset.
An example of a high-likelihood/low-consequence asset would be a ventilation fan in a pump station.
The consequence of the fan failing may be relatively low and, as a result, expensive maintenance
activities should not be performed on an inexpensive fan. Instead, performing routine PM to extend
the life of the fan should be done at a frequency that is cost-effective and the fan should be replaced
upon failure. Spare fans may be kept on hand or an on-call contract with a vendor may be used, if
appropriate.
The second region of moderate-risk assets are assets that have a high consequence of failure but
are not very likely to fail. These assets should receive condition-based maintenance care. This
maintenance strategy includes the same PM identified above but also includes predictive
maintenance (PdM), which includes technologies and practices designed to evaluate assets in
operation and, based on known failure modes, predict failures before they occur. PdM technologies
include vibration monitoring, infrared detection, oil analysis, and other condition evaluative tools.
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Once these measures identify deteriorating condition, corrective maintenance activities should be
taken to prevent a failure and the spare parts strategy should reflect that the high consequence of
failure requires that these assets be non-functional for as short a period of time as possible. The
frequency of these maintenance activities should be based on the condition of the asset; as the
condition declines, more frequent maintenance efforts may be required.
An example of a high-consequence/low-likelihood asset would be a new sewer line serving the City’s
downtown area. The sewer may be relatively unlikely to fail, but the costs of a failure are such that
preventing a failure is worth the cost of PdM activities. Standard PM such as jet cleaning may still be
appropriate, but PdM activities such as monitoring the line via CCTV are appropriate to identify
failures before they occur. Once a failure has been identified, the spare parts strategy should be
such that the time for repair or replacement minimizes the loss of service to the City’s customers.
This may mean keeping spare supplies on hand or having an on-call contract with a contractor for
quick repairs.
The assets with the lowest risk should receive only minimal, routine PM and most maintenance
activities should be reactive. It may be expected to run these assets to failure as the consequences
of failure are low. Because of the low consequence and likelihood of failure, replacements for these
assets should be ordered rather than kept as spare parts in order to minimize costs. A sump pump in
a pump station may have a low likelihood of failing and a low consequence in case of failure.
Occasional routine maintenance may be conducted on sump pumps but in general, they are allowed
to run to failure. Once they have failed, it may be more cost-effective to purchase a new sump pump
“off the shelf” rather than rebuild the existing pump or carry spares.
Table 9-3 summarizes the criticality-based maintenance strategies.
Table 9-3. Criticality-Based Maintenance Strategy Summary
Asset criticality Maintenance strategy Frequency
basis
Spare parts
strategy
Risk
optimization
High Engineer-out: mitigate risk by minimizing the
likelihood and/or consequence of a failure
None None Unacceptable
risk
Moderate
(high-likelihood)
Time-based: routine PM sustains the asset’s
condition and extends its life
Economic Prepare for high
rate of failure
Minimize risk
Moderate
(high-
consequence)
Condition-based: routine PM is supplemented with
PdM to identify failures before they occur
Asset condition Minimize
downtime
No unexpected
failures
Low Reactive: only minimal routine maintenance is done
to sustain the asset’s condition
Economic or as
needed
No spares Run to failure
9.3.4 Condition Assessments
For the City’s roughly 5,500 pipe segments, PdM activities will require condition assessments of
pipes through CCTV inspections. As with the maintenance strategies, the priority and frequency of
CCTV inspections should be related to the relative criticality of the pipe being assessed. High-
criticality pipes (those that are in the top 20 percent of the criticality scoring) should get the first
priority in receiving inspections and subsequent inspections should be more frequent for these pipes
than for less critical pipes. Moderate-criticality pipes (pipes that are in the next 30 percent of
criticality scoring) should also receive inspections when available but should be on a less frequent
recurring schedule than highly critical pipes. Low-criticality pipes should receive inspections only if
the resources are available without hindering the inspection of high- and moderate-criticality pipes.
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After condition assessments have been completed, the results should be reentered into the criticality
model to either update or confirm the criticality rating. Entering condition assessment data could
result in some pipes considered highly critical to be downgraded to moderately critical or could result
in some pipes thought to be only moderately critical to become more critical. For example, currently
there are two pipes crossing the Green River that should be included in the City’s next round of CCTV
inspections. If the results of the inspection show that the pipes are in excellent condition, the pipes
may be considered less critical and may not need to be reevaluated for a number of years. However,
if the inspection shows that the pipes are in poor condition, more frequent inspection may be
needed or including a replacement/lining of the pipes in the next CIP may be appropriate.
9.3.5 Continual Improvement
Once asset criticality and the optimal maintenance strategy have been identified, continual
reevaluation is important to ensure that the most appropriate strategy has been identified. This
process includes reevaluating the likelihood and consequence factors to ensure that they accurately
measure the risk an asset carries, recalculating each asset’s criticality to identify any changes since
the last evaluation, and reviewing each asset’s maintenance and spare parts strategy to make
certain that the appropriate level and frequency of activities are being performed. This continual
improvement guarantees that the minimal life-cycle cost is being achieved for each of the City’s
assets while still meeting the City’s desired LOS.
9.4 Discharge Quality Control
The characteristics of sewage discharged to the collection system can have negative impacts on
wastewater treatment and conveyance capability. Such discharges—which include rags, diapers,
harmful chemicals, pharmaceuticals, and FOG—should be minimized to the maximum extent
possible.
9.4.1 Control of Fats, Oils, and Greases
Engineering currently employs a 0.25 FTE water resources technician to implement and oversee the
City FOG Reduction Program. This program seeks to enforce the City’s code prohibiting the discharge
of FOG by restaurants and other FSEs by requiring the submittal of a FOG control plan as a
requirement to obtain a business license. The control plans must outline best management practices
that will be taken by the business, such as dry-wiping plates, installing and/or regularly cleaning a
grease trap or interceptor, and disposing of grease by recycling it or disposing of it with solid waste. It
is recommended (see Section 7.6) that the City continues the current FOG Reduction Program if not
expand it to include proactive inspections and public outreach activities.
9.4.2 Industrial Waste
As applications for discharge permits are reviewed by City staff, activities, mainly industrial, that are
likely to introduce chemicals or other materials to the sanitary sewer system, are identified.
Applicants are directed to coordinate with the King County Wastewater Treatment Division’s
Industrial Waste Program for the required level of discharge authorization for that activity.
9.4.3 Public Education
The City should continue to educate the general public about what is appropriate to put in the sewer
system. Continued use of bill stuffers, posters, general announcements, and other actions to inform
the public about the harmful effects that some discharges have to the system is recommended.
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9.5 Hazard Planning
Auburn is situated in a geographic area where natural hazards exist. Specifically, the city’s proximity
to the Green and White rivers presents the potential for flooding and nearby Mt. Rainier looms as a
volcanic and lahar hazard. In addition, the numerous faults present in the Puget Sound lowlands
increase the likelihood of an earthquake. The Utility should understand the vulnerability of facilities
to such natural hazards to be prepared for responding if such an event should occur. The City has
prepared a Public Works Emergency Response Manual (see Section 7.4.2) to serve as a guide on
how to handle emergency situations.
An evaluation of sewer facilities for hazard planning purposes should be completed. The evaluation
should identify the potential hazards for Auburn and assess the vulnerability of sewer facilities to the
hazards. As a result of the evaluation, a plan outlining the hazards, facilities vulnerable to hazards,
and activities for mitigating the risk associated with the hazards should be developed.
9.6 Maintenance Issues
Maintenance crews have expressed several areas of concern that did not rise to the level of a CIP
project based on currently available information. However, they merit additional investigations or
research to improve LOS.
9.6.1 105th Place SE and Lea Hill Road SE
The sewer running west down Lea Hill Road SE is very steep and then encounters the 8th Street
siphon at the bottom of the hill. There have been odor issues/complaints at this site and it is
possible that entrapped air is reducing the capacity of the pipe.
9.6.2 Sewers Crossing Freeway
Three City-owned sewers cross underneath State Route 167 with both sides of the sewers located
within wetlands. There is very limited access to these sewers and they have never been inspected.
9.6.3 Sewers within Easements
Sewers that are located within easements, especially ones located in backyards of houses, are
difficult to access. Either the sewers are physically constrained by fences or overgrown vegetation
limits required access to the sewers for proper maintenance.
9.7 SEPA Compliance
The Washington State Environmental Policy Act (SEPA) environmental checklist was completed by
the City as part of this Plan update. A letter documenting the “Determination of Non-Significance” is
located in Appendix D.
9.8 Schedule
Figure 9-4 outlines the general schedule for CIP and monitoring over the next 6 years. Projects
marked as potential activities are tasks that may be needed to address changing conditions or
updated modeling. In cases of funding or resource scarcity, activities should be performed in the
order of their impact on addressing the gap between the City’s expected LOS and the actual LOS
being provided.
Chapter 9 City of Auburn Comprehensive Sewer Plan
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Project
number Project name 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
6–Year CIP 7–20-Year CIP
1 Sanitary Sewer Repair & Replacement/System Improvements
2 Street Utility Improvements
3 Vactor Decant Study
4 Sewer Pump Station Replacement/Improvement
5 Siphon Assessment
6 Pump Station Condition Assessment
7 MH Ring and Cover Replacement
8 Cleaning and Inspection of Large-Diameter Pipe
9 Inflow and Infiltration Study
10 Plan Update
Figure 9-4. City of Auburn Sewer Plan implementation timeline
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Chapter 10
Limitations
This document was prepared solely for the City of Auburn in accordance with professional standards
at the time the services were performed and in accordance with the contract between the City of
Auburn and Brown and Caldwell dated December 6, 2013. This document is governed by the specific
scope of work authorized by the City of Auburn it is not intended to be relied upon by any other party
except for regulatory authorities contemplated by the scope of work. We have relied on information
or instructions provided by the City of Auburn and other parties and, unless otherwise expressly
indicated, have made no independent investigation as to the validity, completeness, or accuracy of
such information.
Chapter 11
References
Auburn City Code (ACC). 2014. http://www.codepublishing.com/wa/auburn/.
City of Auburn Comprehensive Plan (Comp Plan). Amended 2008. City of
Auburn. http://www.auburnwa.gov/doing_business/community_development/planning/comprehensive_plan.ht
m
King County, 2002. 2001/2002 Wet Weather Flow Monitoring; Regional Infiltration/ Inflow (I/I) Control Program.
King county Department of Natural Resources and Parks, Wastewater Division. June 2002.
Brown and Caldwell, December 2009. City of Auburn Comprehensive Sewer Plan. Prepared for the City of Auburn by
Brown and Caldwell.