HomeMy WebLinkAboutResolution 06-25 06/05/2006
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RESOLUTION
NO. 06-25
A RESOLUTION OF THE CITY OF SPRINGFIELD COMMON COUNCIL ADOPTING AN
AMENDED METHODOLOGY AND CHARGE SCHEDULE FOR THE REGIONAL
WASTEWATER SYSTEM DEVELOPMENT CHARGE AS SET FORTH IN THE SPRINGFIELD
MUNICIPAL CODE.
WHEREAS, February 9,1977, the City of Springfield, the City of Eugene, and Lane County (the
Governing Bodies) entered into an intergovernmental agreement (IGA) which established the
Metropolitan Wastewater Management Commission (MWMC).
WHEREAS, MWMC, pursuant to the IGA between the Governing Bodies, is responsible for
administration and operation of the regional wastewater system; and
WHEREAS, Appendix B, section D of the IGA directs that MWMC develop and levy "connection
fees (System Development Charges), considering different types of usage on all new
connections"
WHEREAS, the existing MWMC System Development Charge ("SDC") Methodology was
adopted by MWMC on April 1 , 2004 ("Methodology"), after a public hearing, and forwarded to
the Cities of Eugene and Springfield and Lane County (collectively "Governing Bodies") for
adoption; and
WHEREAS, the existing Methodology was approved by the common council of the City of
Eugene on June 28, 2004, and by the Common Council of the City of Springfield on June 21,
2004; and
WHEREAS, MWMC has determined that certain modifications to the user categories contained
in Appendix D of the Methodology are timely, appropriate, and consistent with the governing
statutes, ORS 223.297 et seq.; and
WHEREAS, MWMC has determined that modifications to Elements 2 and 5 of the Methodology,
to allow the cost of projects contained in the 20-Year Project List to be periodically escalated by
the Engineering News Record national 20-city average Construction Cost Index ("ENR"), are
timely, appropriate, and consistent with the governing statutes, ORS 223.297 et seq.; and
WHEREAS, ORS 223.304(8) allows for SDCs to be adjusted by the periodic application of a
specific cost index, such as the ENR; and
WHEREAS, on April 20, 2006, MWMC held a public hearing to consider the aforementioned
modifications to the Methodology; and
WHEREAS, MWMC, having considered the comments made during the public hearing, the
recommendation of staff and legal counsel and being otherwise fully informed adopted the
modifications to the Regional Wastewater SDC methodology; and
WHEREAS, The Springfield Municipal Code Section 3.354 establishes that "the Regional
Sanitary Sewerage Facility SDC methodology shall be established by resolution of the City
Council and may be adopted and amended concurrent with the establishment or revision of the
system development charge."
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NOW, THEREFORE, BE IT RESOLVED by the Common Council of the City of Springfield as
follows:
1) The Regional Wastewater SDC methodology, which is attached as Attachment "A," is hereby
adopted and shall take effect with bills rendered on or after July 1, 2006.
2) This resolution shall take effect immediately upon adoption by the Council and signature by
the Mayor.
Council Presiden
...Ma~or
uncil of the City of Springfield this 5th day of June, 2006.
ATTEST:
Jnu~
a, City Recorder
~:.':V;EWED 11 APPROVFD
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DATE: (01 ,.~ ab
OFFICE OF CITY ATTORNEY
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Attachment A
System Development Charge
Methodology
Prepared for
Metropolitan Wastewater Management Commission
G~
partners in wastewater management
Modifications proposed March 16, 2006
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Contents
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System Development O1arge Methodology ........................................................................... 4
In.troduction ...................................................................................................................... 4
System Development O1.arge Methodology ................................................................ 5
Overview.............................................................................................................. 5
Methodology Element One: Determine Growth Capacity Needs ............... 7
Step One - Capacity Parameters ................................................................. 7
Step Two - Growth Capacity Requirements............................................. 9
Methodology Element Two: Develop Cost Basis ........................................... 9
Step One - System \T aluation .................................................................... 10
Step Two - Existing System Allocation ................................................... 10
Step TIrree - Project Cost Allocation ................................................... M 12
Step Four - Adjustments............................................................................ 15
Methodology Element TIrree: Develop SDC Schedule........................... 18 15
Methodology Element Four: Calculate Revenue Offsets and Credits....... 16
Past Payments ..... .............. ...... ......... ......... ................ ...... ....... ................ ~ 16
Future Payments ...... .......... ...................................... ... .... ........... ........... -1-9-17
Methodology Element Five: Periodic modification of existing sytem and
future project values. . ... .. ... ... .... ... .. ... . .. . .. . .. ..... .. .. . .. .......... .. . ... . . ... 21
Appendixes
A System Component Definitions
B Capacity Parameter Allocation
C Growth Capacity Allocation Documentation
D User Capacity Requirements
E GO Bond Credit Calculation
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Tables
1 Summary of Key Methodological Requirements ....................................................................4
2 Example Calculation for Single (Average Flow) Capacity Parameter .................................6
3 Summary of Facility Process Component Allocation to System Capacity Parameters .....9
4 Existing System Available Capacity by Parameter ...............................................................11
5 Summary of Project Type Allocation Criteria............................................................,......1e 14
6 Growth Allocation Percentages by Project Type...............................................................:gz 15
B-1 Design Criteria Basis For Unit Processes Driven By Peak Flow ................................ ~ 22
C-l Capacity Summary of MWMC Liquids Facilities ....................................................... C~ 27
C-2 Projected 2025 Peak Flow Breakdown .......................................................................... C-W 29
C-3 Capacity Summary of MWMC Biosolids Facilities (annual average dry tons per
year) ................................................................................................................................... C ~ 31
E-l GO Bond Credit per $1,000 Assessed Value By Annexation Year ......~......................E~ 37
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Figures
1 Overview ofMWMC SOC Methodology............................................................................ 2
2 Existing System Allocation ........ ................ .......................... ...... ........ ...... ................... .... ...... 3
3 Proj ect Cost Allocation.. ........... ...... ...... ......... ;... ........ ......................... ............. ............. ......... 9
4 SDC Schedule Development.......... .......... ................. ..... ........... ......... ......... ....... ..... .... ........ 12
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System Development Charge Methodology.
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Introduction
This document serves as the system development charge (SDq methodology for the
Metropolitan Wastewater Management Commission (MWMq Regional Wastewater
System. The MWMC is the regional wastewater treatment agency for the Eugene- '
Springfield metropolitan area. System development charges may be collected from all
development that connects to the Regional Wastewater System, including development that
changes the use of existing development, when the change of use results in a greater impact
on the system.
The methodology contained in this document was developed in accordance with Oregon
SDC legislation (ORS 223.297-223.314), and with the guidance of a Citizen Advisory
Committee (CAq appointed by MWMC. Table 1 provides a comparison of key
methodological requirements from the Oregon Revised Statute (ORS) to elements of the
MWMC methodology.
TABLE 1
Summary of Key Methodological Requirements
MWMC Methodology
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Oregon Law Requirement
Reimbursement Fee
Determine that existing capacity exists
Methodology based on, when applicable:
(a) Rate-making principles employed to finance
publicly-owned capital improvements
(b) Prior contributions by existing users
(c) Gift or grants
(d) Value of unused capacity or cost of existing
facilities
(e) Other relevant factors
Promote objective of future system users
contributing no more than an equitable share of
existing system costs
Explicitly calculates the portion of existing capacity available to
new users based on rated design capacities.
Methodology includes:
(a) Consideration of capital financing costs
(b) Adjustment for grant-funded facilities
(c) Valuation based on appreciated cost 0.e., adjusted for
inflation)
(d) Determination of unused capacity
(1) Includes a credit against SDCs for properties subject to
past general obligation bond debt service charges through
property tax: payments.
(2) Provides guidance to calculate a credit against SDCs for
Mure estimated user charge payments used to fund capital
included on the SDC project list.
Improvement Fee
Methodology demonstrates consideration of
projected costs of capital improvements identified
in an adopted plan or list
Provides a structured process for allocation of capital project
costs that is to be applied to an adopted project list
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TABLE 1
Summary of Key Methodological Requirements
Oregon law Requirement
Methodology demonstrates consideration of the
need for increased capacity in the system to meet
Mure users' demands
Combined Fee
Demonstrate that charge is not based on
providing the same capacity
MWMC Methodology
Allocates Mure improvement costs to growth in proportion to
capacity requirements
Determines total growth capacity requirements and the portion
of capacity to be met through existing system available
capacity and Mure capacity expansion. Calculates a weighted
average cost of capacity.
System Development Charge Methodology
Overview
The SDC methodology for MWMC is based on a combined reimbursement and
improvement structure, as shown in Figure 1. The methodology consists of the following
elements:
. Determine capacity needs
. Develop cost basis
. Develop SDC schedule
. Calculate revenue offsets and credits
FIGURE 1-OVERVIEW OF MWMC SDC METHODOLOGY
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1 Growth units (Avg. Flow, Peak Flow, BOD, TSS) 1
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The reimbursement fee is based on the value of available capacity in the system that will
serve growth. The improvement fee is based on future facility costs associated with
providing growth's additional capacity needs (above what :"s already available in the .
system). Together, the reimbursement and improvement fees recover costs equal to
growth's capacity needs. _
Existing system available capacity and future improvement costs needed to expand capacity
for growth are distributed to capacity parameters (average flow, peak flow, biochemical
oxygen demand [BOD], and total suspended solids [TSS]), and spread over the total growth
units projected for the period to determine weighted average reimbursement and
improvement unit costs. The SDCs for individual developments are then determined by
applying the unit costs (by fee element and capacity parameter) to the individual
development estimated capacity requirements, and summing the results. The total SDC for
each development is then reduced by any applicable credits for past and future capital
payments.
Table 2 provides an example calculation for a single capacity parameter. The numbers
included in the table are intended to illustrate the methodology only (when applied to the
single capacity parameter of average flow); the numbers do not represent MWMC planning
criteria or cost data. Furthermore, the total SDC would include similar calculations for other
capacity parameters (i.e., peak flow, BOD, and TSS). In the example provided, total system
capacity needs at the end of the planning period are 60 million gallons per day (mgd).
Existing users are estimated to require 45 mgd (90 percent) of existing capacity, leaving
5 mgd (10 percent) available for growth. However, growth's total needs are 15 mgd,
meaning that additional investment will be required to expand system capacity by 10mgd.
TABLE 2
Example Calculation for Single (Average Flow) Capacity Parameter*
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Determine Capacity Needs
Systemwide Capacity (tngd)
Existing Users (mgd)
Growth (mgd)
60
45
15
Existing Future
System Expansion
50 10
45 0
5 10
10% 100%
$50,000,000 $12,000,000
$5,000,000 $12,000,000
Element
Total
Determine Cost Basis Needs
Systemwide Cost
Growth Cost
$17,000,000
Determine SDC Schedule
Weighted Average Unit Cost ($/mgd)
User Capacity Requirement (mgd)
Total SDC
$1,133,333
0.00035
$396.67
$333,333
0.00035
$116.67
$800,000
0.00035
$280.00
*Example only; not MWMC specific
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The example reimbursement fee cost basis includes 10 percent ($5 million) of existing
system value, associated with providing 5 mgd of capacity. The improvement fee cost basis
includes the costs to expand the facilities by 10 mgd, in this case estimated to be $12 million.
The total costs allocated to growth are equal to the total capacity required by growth (5 mgd
existing +10 mgd expansion) = 15 mgd total.
At this point the SDC schedule can be developed. First, the weighted average unit costs are
developed. This is accomplished by dividing the reimbursement fee and improvement fee
cost bases by the tatal growth capacity units (15 mgd in this case). By dividing the individual
fee elements by the total growth units, the combined fee is based on a weighted average cost
per unit. This is demonstrated in Table 2 where the individual unit costs are $333,000 per
mgd ($5 million/15 mgd) and $800,000 per mgd ($12 million/15 mgd), respectively, for
reimbursement and improvement elements; and $1.1 million per mgd ($17 million/15 mgd)
overall. The SDC for a user who requires 350 gallons per day (.000350 mgd) would equal
$116.67 reimbursement ($333,333 X 0.000350) + $280 improvement ($800,000 X 0.00035) for a
total of $396.67. The same fee would result from using the total cost per unit ($1.13 per
. gallon per day) multiplied by the 350-gallon-per-day user requirements.
As the example demonstrates, the methodology meets the key requirements of the law, as
identified in Table 1:
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· Determirles the amount of available capacity that exists and allocates costs to growth
accordingly.
· Allocates improvement costs to growth in proportion to future capacity needs.
· Does not recover the costs of the same capacity through the reimbursement and
improvement fees. Recovers cost associated with existing capacity through the
reimbursement fee, and recovers costs associated with new capacity through the
improvement fee. The charges to individual developments are based on a weighted
average cost of capacity.
Each element of the methodology is discussed in more detail below.
Methodology Element One: Determine Growth Capacity Needs
The Oregon SDC law requires explicit analysis of capacity required to serve growth - and
demonstration of how those capacity needs will be met through existing and future
facilities. Therefore, it is necessary to first determine the appropriate capacity parameter(s),
and growth's capacity requirements.
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Step One. Capacity Parameters
The appropriate capacity measure relates to the sizing criteria of the wastewater system, and
may, to improve equity, require consideration of multiple parameters to assess the impact of
the utility's various types of users. As wastewater systems must be sized to meet all of their
customers' demands, flows and strength loadings are important sizing criteria. MWMC
provides service to a diverse customer base, so consideration of varying flow and load
requirements of different customer types is one facet that ensures the equity of the SDCs.
. The four capacity measures or parameters used in the methodology are:
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. Average flow
. Peak flow
. BOD
. TSS
These parameters are defined as follows:
. Average Flow- The average daily flow in the dry season as defined in the National
Pollution Discharge Elimination System (NPDES) permit. Because the NPDES permit
requires the Eugene-Springfield Water Pollution Control Facility (wpCF) to meet permit
discharge limits on a monthly basis, the average flow is presented in terms of dry season
maximum month values when discussing "capacity." The dry season maximum month
flow includes base flow (customer flow) and the baseline or dry season infiltration and
inflow (III).
. Peak Flow- The peak hour flow in the wet season associated with the 5-year, 24-hour
storm event. Peak flow includes average flow and the additional increment of wet
weather III.
. Biochemical Oxygen Demand - The quantity of oxygen used in the biochemical
oxidation of organic matter in a specified time and at a specified temperature. BOD is a
measurement of wastewater strength.
. Total Suspended Solids-Solids in the wastewater that are removable by laboratory
filtering and approximate the quantity of solids that are available to be removed from
the wastewater through sedimentation. TSS is a measurement of wastewater strength.
Table 3 provides the allocations of existing and future facility process components to the
system capacity parameters: average flow, peak flow, BOD, and TSS. A description of
process components is provided in Appendix A. The rationale for the allocation percentages
is provided in Appendix B. These allocations are used to determine the projected costs of
capacity to be used by new development that establish the reimbursement fee and
improvement fee cost bases. The underlying approach is to evaluate the following criteria
for each facility process component:
. Functional performance
. Design basis
The functional performance criterion considers the actual purpose of the facility on a daily
basis. Is the purpose of the facility to remove BOD or TSS from the wastewater? Or is the
purpose of the facility to simply pass the flow (average andlor peak) and remove some
other parameter not represented by BOD or TSS such as screenings, grit, or pathogens?
These questions are answered by the functional performance component. The design basis
considers what system capacity parameter or combination of parameters drives the sizing of
the facility and, therefore, the constructed cost. The allocation basis for each facility
component presented in Table 3 combines both the functional performance and design basis
considerations. In addition to these system parameters, because there can be projects that
provide overall support for the wastewater system, a separate category of "indirect"
support facilities is used to provide for reallocation of these support-type costs across all of
the system capacity parameters.
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TABLE 3
. Summary of Facility Process Component Allocation to System Capacity Parameters
System Capacity Parameter
Average Peak
Facility Process Component Flow Flow BOD TSS Indirect Total
Collection system pipeline ~ % 1
Collection system pump stations ~ % 1
Preliminary treatment K % 1
Primary treatment ~ ~ %
Secondary treatment ~ % Y. 1
Disinfection/outfall Y. % 1
BioSjolids (same for all three subcomponents) % % 1
Tertiary filters Y. y. % 1
Reuse facilities 1 1
Odor control % %
Peak flow management 1 1
Support facilities (Indirects) 1
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Step Two. Growth Capacity Requirements
In. developing SDCs, costs related to growth (see 'Cost Basis' below) are spread over
growth's total capacity requirements over the study period to determine the overall cost per
unit of growth by capacity measure. The study period is defined as a 20-year period,
consistent with facility planning requirements. The Department of Environmental Quality
(DEQ) stipulates that entities that own and operate wastewater facilities assume a 20-year
planning horizon when developing facility plans (see DEQ Guidance for Development of
Wastewater Facilities Plans, 2000).
To determine the capacity required by growth, the capacity required by existing users is
subtracted from the capacity projected in the facility plan to be required at the end of the
planning period. For peak flow estimates, existing users' current capacity requirements are
adjusted for anticipated III reductions (see Guidelines for the Preparation of Facilities Plans
and Environmental Reports for Community Wastewater Projects, 1999).
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Methodology Element Two: Develop Cost Basis
The cost basis represents the total costs that the SDCs Cl!e intended to recover. The following
methodological issues were addressed in developing the reimbursement and improvement
fee cost bases: .
I. Existing System Valuation (Reimbursement Fee) - The method for valuing existing
facilities with capacity to serve growth.
· Existing System Allocation (Reimbursement Fee) - The method for allocating existing
system facility value to growth.
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I. Project Cost Valuation (Improvement Fee) The method for valuing future projects.
. Project Cost Allocation (Improvement Fee) - The method for allocating future projects .
to growth.
. Adjustments-Deductions or additions to the cost basis to recognize past or future
capital funding methods.
Each issue is discussed below.
Step One. ExistinQ System Valuation
Calculation of the reimbursement fee begins with a review of MV\lMC's fixed asset records
to determine the value of the existing system. The system is valued based on the inflation
adjusted original cost approach. Under this approach, the original cost of existing system
assets is adjusted by the Engineering News-Record national20-city average Construction Cost
In.dex from the time of construction to estimate current values. The inflation adjusted cost
approach recognizes appreciation in the system since assets were constructed and assumes
that the wastewater system is maintained in perpetuity.
Step Two. Existing System Allocation
The existing system allocation methodology, for use in determining the reimbursement fee
cost basis, is a three-step allocation process1 comprised of the following steps, as illustrated
in Figure 2:
R-l. Allocate existing facility costs to facility process components (e.g., primary treatment,
secondary treatment). .
R-2. Allocate costs by component to system capacity parameters (e.g., average flow, peak
flow).
R-3. Allocate costs to growth based on estimated available capacity by service parameter.
The allocation of existing facility costs to facility process components is fairly straight-
forward, as most projects relate directly to an individual component (e.g., secondary
clarifiers are a part of secondary treatment), or support the entire treatment system (e.g.,
control systems). Existing facility costs (valued in terms of inflation-adjusted costs) by
process component are then allocated to capacity parameters based on the allocation
fractions in Table 3.
The final step in the allocation process is to multiply the costs by capacity parameter by the
percent of capacity available by parameter. To determine the available capacity for a
parameter, the amount of capacity that is currently being used (or required for existing
users) is subtracted from the current rated capacity. If the current capacity requirement is
equal to or greater than the existing capacity, then there is no available capacity, and none of
the costs related to that parameter is included in the reimbursement fee cost basis. Table 4
shows existing system available capacity by parameter based on system planning criteria.
The documentation for these figures is provided in Appendix C.
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Appendixes
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APPENDIX A
System Component Definitions
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The below facility process components were selected because they represent existing
distinct processes/ components, as well as new processes/ components anticipated in the
future (e.g., tertiary filters and effluent reuse). These facility components also relate
differently to system capacity parameters (discussed in Methodology Element Two), so the
initial allocation of project costs to facility components facilitates the next step of allocating
costs to capacity parameters, and ultimately to user type. As regulatory requirements
change in the future, MWMC should review the facility component categories, and update
as appropriate. . .
Collection System Pipeline - The pipelines owned and operated by MVVMC that collect
sewage from individual customers and deliver it to the treatment plant.
Collection System Pump Stations - MW'MC pump stations that impart energy into the
wastewater so that it flows through the collection system pipes or is lifted to a higher
elevation. The influent screw pumps at the Eugene/Springfield Water Pollution Control
Facility (WPCF) are included in this component.
Preliminary Treatment-Screenings and grit removal facilities. Preliminary treatment
facilities are sometimes referred to as headworks facilities because they are located at the .-
front or head end of treatment plants.
Primary Treatment- The sedimentation process intended to remove suspended solids from
the wastewater. This component includes the primary sedimentation settling tanks and
associated pumping systems for material that is removed from the top (scum/ skimmings)
and bottom (primary sludge) of the settling tanks.
Secondary Treatment - A biological process to remove the soluble and colloidal organic
matter that remains after primary treatment. Facilities typically include aeration basins and
the associated blowers t:hat provide air to the basins, and secondary clarification settling
tanks and the associated pumping facilities that transport the settled biological sludge to
subsequent biosolids processing facilities.
DisinfectionjOutfall- Process elements at the downstream end of the treabnent process.
Disinfection kills or inactivates remaining pathogens contained in the treated wastewater,
and the outfall conveys the treated wastewater to the Willamette River where it can be
distributed through a diffuser in an environmentally sound manner.
Biosolids - Management and disposal of the organic and inorganic suspended solids that
have been removed from the wastewater through the treatment processes. This facility
component is divided mto three subcomponents because of differences in available and
future required capacity. The three subcomponents are as follows:
. General- The general subcomponent consists of biosolids thickening and anaerobic
digestion at the 'WPCF; the biosolids pump station/ force main system that conveys
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digested biosolids from the WPCF to the Biosolids Management Facility (EMF); and
facultative sludge storage lagoons and drying beds at the remote BMF. The majority of
the infrastructure associated with this "General" subcomponent were constructed in the
1980s and early 1990s.
Dewatering-MWMC-installed mechanical biosolids dewatering at the remote BMF for
the purpose of removing water from the biosolids so that the remaining biosolids
volume is reduced. This dewatering facility was designed to accommodate 7,000 dry
tons of biosolids on an annual average basis.
. Biocycle Fann - MWMC is in the process of expanding the capability of the biosolids
management program by constructing a poplar plantation or biocycle farm (BF) that can
accept non-dewatered biosolids, therefore limiting dependence on the cooperative farms
land application program that typically uses dewatered biosolids.
Tertiary Filters-Filters to remove TSS and to a lesser degree BOD/ammonia from the
secondary effluent.
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Reuse Facilities - These facilities enable reuse of effluent and include UV disinfection;
pumping of filtered, disinfected effluent; pipelines to convey the water to the end use site;
and irrigation distribution/ application systems.
Odor Control- Facilities that collect and treat odorous air generated by the treatment of
wastewater and biosolids.
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Peak Flow Management-A new facility component that functions to convey, treat, and
discharge wet season peak flow (based on the 5-year, 24-hour rainfall event). Facilities must
be provided so that the peak flow can reach and pass through the WPCF without
overtopping structures so that untreated/ partially treated sewage does not spill onto the
ground and/ or into waterways.
Support Facilities (In directs) - These facilities serve MWMC's overall mission as opposed
to one specific facility component. Examples include control systems, civil infrastructure
such as roads within the WPCF site, and equipment storfl.ge facilities.
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APPENDIX B
Capacity Parameter Allocation Basis
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System Capacity Parameters are based on permitting requirements. Facility process
components (defined in Appendix: A) are allocated to each of the system capacity
parameters, as described below.
Collection System Pipelines
This category consists of major gravity sewer pipelines and force mains (pressure lines) that
convey flow for the regional wastewater collection system. Since the primary function of the
pipelines is to convey flow, the allocation is assigned to either average or peak flow and
none to wastewater strength. parameters (i.e., BOD and TSS). The majority of the time the
conveyance system is' carrying average flows. However, the limiting design criteria when
sizing pipelines is based on peak flows.
An assessment of the wet season 1/1, which is the key driver in determining the peak flows,
can be used as a guide in determining the average/peak allocation breakdown. Table B-1
presents the wet season If I as a percentage of total peak flow for existing capacity, current
loading, and future required capacity.
TABLE B-1
Design Criteria Basis For Unit Processes Driven By Peak Flow
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Average Wet Weather In as a
Flow Wet Weather UI Total Peak Flow Percentage of Total Peak
'(mgd) (mgd) (mgd) Flow, %
'Existing capacity 49 126 175 72%
Current loading (current 43.8 220.2 264 83%
capacity required)
Projected 2025 loading 59.3 218.7a 277 79%
(Mure capacity required)
Notes:
a) Net reduction in totallll occurs between now and 2025 as a result of III reduction efforts by the cities.
The range of wet weather 1/1 as a percentage of total peak flow for these three scenarios
ranges from 72 to 84 percent The arithmetic average of these three values is 78 percent
Therefore, a reasonable approach is to allocate a quarter to functional use basis, or average
flow; and three quarters to the design criteria sizing basis, or peak flow.
. Average Flow -1/4
. Peak Flow - 3/4
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Collection System Pump Stations
The category collection system pump stations consist of pump stations that impart
additional head or pressure to the wastewater so that the flow is conveyed to the WPCF. An
example of such a facility is the Wilakenzie Pump Station. These regional pump stations
have the same functional and design criteria basis as the regional collection system
pipelines, and, therefore, the allocations are:
. Average Flow-1/4
. Peak Flow - 3/4
Preliminary Treatment
Preliminary treatment facilities are located between the pump stations and primary
treatment, consisting of screenings and grit removal facilities. Minimal organic matter
(BOD) is removed during preliminary treatm~t. Also, solid materials removed during
preliminary treatment tend to be large and heavy in nature; these materials are not typically
considered a "suspended" material (or TSS). Consequently, the loading parameters of BOD
and TSS generally do not apply to preliminary treatment, and the unit process category is
entirely flow based. The functional and design criteria basis for preliminary treatment are
very similar to that of the collection system facilities, and, therefore, the allocation is
identical to the preceding categories. The split between average and peak flow is as follows:
. Average Flow - 1/4
. Peak Flow - 3/4
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Primary Treatment
Primary treatment consists of the four, large, circular concrete basins (primary clarifiers) and
the associated equipment used to remove solids that settle to the bottom of the basins. The
purpose of primary treatment from a functional basis is to remove TSS and to a lesser
degree BOD. Typical percent removal across primary treatment for TSS and BOD are 60 and
30 percent, respectively. In other words, twice as much TSS is removed relative to BOD.
For the design criteria basis, typical primary clarifiers sizing is governed by both average
and peak flow, but for MWMC, where the parallel primary I secondary approach is
proposed for peak flow management, the peak flow will be split between primary treatment
and secondary treatment Likewise, if the high-rate clarification peak flow management is
ultimately implemented (because regulatory approval is not obtained for the parallel
primary I secondary approach), the peak flow will be split between the primary treatment
and the high-rate clarification. Therefore, only average flow is considered in the cost
allocation.
Combining t;he functional basis with the design criteria basis, the following allocation is for
primary treatment
. Average Flow-1/4
· BOD-1/4
. TSS-1/2
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Secondary Treatment
Secondary treatment consists of two trains of aeration basins, eight secondary clarifiers, and .
the associated blowers and pumps that function to treat and remove organic loading (BOD)
and to a lesser extent TSS from the wastewater. On a functional basis, secondary treatment
is regarded as removing roughly twice as much BOD relative to TSS.
For the design criteria basis, typical secondary treatment sizing is governed by both average
and peak flow, but for MWMC, where the parallel primary / secondary approach (or high-
rate clarification approach as a second choice) is proposed for peak flow management, the
peak flows will be split between primary treatment and secondary treatment Therefore,
only average flow is considered in the cost allocation.
Combining the functional basis with the design criteria basis, the following allocation is for
secondary treatment
. Average Flow-l/4
. BOD-l/2
· TSS-l/4
Disinfection/Outfall
Following secondary treatment, the wastewater is disinfected (chlorinated and
dechlorinated) and discharged to the Willametle River through an outfall pipe. Both the
function and sizing of these facilities are entirely based on flow. The relationship between
the functional basis and design criteria is identical to that for the collection system facilities
and, therefore, the fo.llowing allocation is for disinfection/ outfall:
. Average Flow-l/4
. Peak Flow - 3/4
.
Biosolids
Biosolids are a byproduct of wastewater treatment and are produced during the primary
treatment, secondary treatment, and to a lesser degree tertiary treatment processes. The
three subcomponents used to allocate biosolids treatment, handling, and disposal/ reuse
costs for purposes of SDC calculations are:
. General
. Dewatering
. Biocycle Farm
The definitions of these subcomponents are presented in Appendix C, Growth Capacity
Allocation Documentation. The three subcomponents were developed for the SDC update
because of the differing available capacities and growth percentages associated with
facilities in the subcomponents. However, in terms of allocating the facility components to
the wastewater parameters, the methodology is identical-independent of which
subcomponent is being considered.
'-----
.
Page 24 OF 37
A-24
.
Biosolids facilities at the VVPCF and the BMF are both sized and function to treat the BOD
and TSS removed during the treatment process; therefore, their allocation is split equally
between BOD and TSS.
· BOD-1/2
. TSS-1/2
Tertiary Filters
The existing WPCF does not have tertiary filters. The 20-year project list recommends that
tertiary filters be installed to enable the VVPCF to consistently meet the NPDES permit
discharge requirements. The permit includes mass limits for BOD and TSS. As influent
flows to the WPCF increase in the future,.the effluent concentration required to meet the
mass limits decreases. Addition of the filters will assist with meeting these more stringent
effluent concentrations. From a functional basis, the main purPose of the filters is to remove
TSS, and to a lesser degree BOD. Prom 'a design criteria sizing basis, average flow Is used to
determine the size of the facilities. In the wet weather season, a portion of the peak flow
may be routed to the filters for additional treatment. However, the associated peak flow
loading rate onto the filters will not be the limiting factor in terms of design criteria sizing.
Following is the allocation for the tertiary filter treatment category:
· Average Flow -1/4
· BOD - 1/4
· TSS - 1/2
.
Reuse Facilities
Reuse facilities may be constructed to comply with more stringent regulatory requirements
related to temperature and/ or thermal load restrictions of Willamette River discharges.
Reuse facilities would allow flow to be diverted from the river by reusing plant effluent for
irrigation. The basic design criterion used to size reuse facilities is average flow; so this
parameter receives 100 percent of the allocation.
· Average Flow - 100 percent
Odor Control
Odor control facilities function by collecting odorous air from preliminary I primary liquids
treatment processes and biosolids treatment/handling processes and treating the air to
remove the odors. Odor generation is dependent on the influent loading levels and,
therefore, the allocation is split equally between BOD and TSS because both parameters
contribute to the sizing and function of the odor control systems.
· BOD - 1/2
· TSS-1/2
.
Peak Flow Management
There are a number of future capital improvement projects that specifically function to
convey, treat, and discharge the wet season peak flow. For example, the parallel
primary/secondary peak flow management approach is proposed solely to address peak
Page 25 OF 37
A-25
flows. Also, there are facilities such as the dry weather headworks where a portion of their
function or design criteria sizing is based on peak flow.
The peak flow management category is allocated entirely to peak flow, as both the ongoing
function and the sizing design criteria sizing are based solely on peak flow.
. Peak Flow - 100 percent
Support Facilities (Indirects)
The support facilities or indirect category captures certain types of treatment plant facilities
that serve multiple functions, such as the laboratory, land acquisition, and instrumentation
and control systems. Costs of these types of facilities are allocated across the other
11 components in proportion to the weighted average allocation percentages. For the
reimburs~ent fee, the weighted average reflects the direct allocation of existing asset costs
to the 11 facility components. For the improvement fee, the weighted average reflects the
allocation of the 20-year project list to the 11 facility components.
. Support facilities allocated proportionally to the other 11 facility components.
Page 26 OF 37
.
.
.
A-26
.
APPENDIX C
Growth Capacity Allocation Documentation
Liquids Treatment
A summary of the MWMC liquids treatment capacity is presented in Table C-l.
TABLE C.1
Capacity Summary of MWMC Liquids Facilities
Average Flow Peak Flow BOD TSS
Population (mgd) (mgd) (Ibs/day) (Ibs/day)
Existing capacity 49 175 66,000 71,600
Current loading (current 217,737 43.8 264 54,800 64,700
capacity required)
Available capacity (value) 5.2 None 11 ,200 6,900
Available capacity (%) 10.5% 0% 17.0% 9.6%
Projected 2025 loading 297,585 59 277 74,000 87,600
(Mure capacity required)
. Growth loading 79,848 15.5 30B 19,200 22,900
Required Capacity 10 102 8,000 16,000
Expansion
Growth share of 2025 load 26.8 26.1% 10.8% 25.9% 26.1%
Growth share of capacity 100% 100% 29.4% 100% 100%
expansion
Notes:
AThe 30-mgd peak flow attributed to growth consists of 15.5 mgd of average flow and 14.5 mgd of wet season III
flow. See the following discussion for a detailed derivation of these values.
The rationale for these values is presented in the following paragraphs.
Average Flow
The existing capacity is stated in the current NPDES permit as 49 mgd that represents the
dry season design rating for the WPCF. The current loading or current required capacity is
43.8 mgd (presented in DSM:M terms). The DSM:M value is used to compare to the dry
season design rating of the WPCF because the NPDES discharge permit stipulates that the
WPCF meet monthly average permit requirements. Therefore, discharge permit
requirements must be met on a dry season, maximum-month influent condition. This
43.8-mgd value is determined as follows:
.
Page 27 OF 37
A-V
Current average flow (presented as DSM:M) = ((129 x 217,737 x 1.5)/1,000,000) + 1. 7i = 43.8
VYhere:
.
129 is the average gallons per capita per day (gpcd) of the dry season values from
1990 to 2002
217,737 is the population served in 2002
1.5 is the selected peaking factor to convert average dry season flow to maximum
month dry season flow (based on 1990 to 2002 data)
1.7i is the current industrial flow in mgd
The available capacity in terms of average fl~w is 5.2 mgd (49 - 43.8).
The projected 2025 average flow is determined as follows:
Projected 2025 average flow (presented DSMM) = ((129 x 297,585 x 1.5)/1,000,000) + 1. 7 =
59.3 mgd
Where:
129 is the average gpcd of the dry season values from 1990 to 2002
297,585 is the projected population to be served in 2025
1.5 is the selected peaking factor to convert average dry season flow to maximum
month dry season flow (based on 1990 to 2002 data)
1.7 is the projected industrial flow in mgd (it has been assumed that the
industrial flow will remain constant over the study period)
The total required capacity to meet the needs of growth in terms of average flow is 15.5 mgd
(59.3 - 43.8).
.
Peak Flow
A summary of the peak flow breakdown is presented in Table C-2 The existing capacity in
terms of peak flow is not defined in the NPDES permit, but the plant was originally
designed for a peak flow of 175 mgd, and therefore that is defined as the existing capacity.
MWMC does not currently have the collection and treatment capabilities to accommodate
the existing peak flow (which is greater than 175 mgd), and therefore the current peak flow
loading (required capacity) cannot be explicitly measured at the WPCF. Using a computer
model of the collection system MWMC is able to estimate the current peak flow. DEQ
d~es the peak flow as the peak hour or peak instantaneous flow that occurs during the
5-year, 24-hoUI storm (3.9 inches of rainfall). Under these rainfall conditions, the model
predicts a current flow of 264 mgd. Therefore, there is no available capacity in terms of peak
flow. Since the current average flow is 43.8 mgd, the current wet season 1/1 is 220.2 mgd
(264 less 43.8).
Using the projected future 2025 population and land use, the model predicts peak flows of
294 mgd without I/I reduction efforts outlined in the 2000 WVVFMP and 277 mgd with I/I
.
Page 28 OF 37
A-2B
.
reduction efforts outlined in the 2000 WWFMP. Therefore, it is estimated that the If I
reduction efforts will reduce III by approximately 17 mgd.
Wet season If I in 2025 attributed to existing users is determined by subtracting the
anticipated reduction in wet season III (17 mgd) from the current wet season III
(220.2 mgd) yielding 203.2 mgd.
Finally, wet season III attributed to growth in 2025 is 14.5 mgd and is determined by taking
the 2025 total peak flow projection of 277 mgd and subtracting both the 2025 average flow
(59.3 mgd) and the 2025 wet season If I attributed to existing users (203.2 mgd). Therefore,
the peak flow in 2025 attributed to growth is 30 mgd (15.5 mgd of average flow plus 14.5 of
wet season If I flow).
TABLE C-2
Projected 2025 Peak Flow Breakdown
Average flow attributed to existing users (includes dry
season Ill)
Average flow attributed to future users Qncludes dry
season In) "
Wet season In attributed to existing users
Wet season III attributed to future users
43.5 mgd
15.5 mgd (59.3 - 43.8)
.
Total peak flow
Total peak flow attributed to growth
203.2 mgd (220.2 - 17)
14.5 mgd {277 - 59.3 - 203.2
277 mgd
30 mgd (15.5 + 14.5)
BOD
The methodology for BOD is similar to that of average flow. The existing capacity, although
not explicitly stated in the current NPDES permit, is 66,000 lbsl day, which was the value
used for the original WPCF design. The current loadirig or current required capacity in
presented in DSMM terms is 54,800 lbs I day and is determined as follows:
Current BOD = (0.185 x 217,737 x 1.3) + 2,402 = 54,800 lbsl day (actual calculated value of
54,7561bsl day rounded to the nearest hundred pounds).
Where:
.
0.185 is the selected pounds per capita per day (Ppcd) based on dry season
values from 1990 to 2002
217,737 is the population served in 2002
1.3 is the selected peaking to convert average dry season load to DSMM load
(based on 1990 to 2002 data)
2,402 is the current industrial BOD load in lbsl day
The available capacity in terms of BOD is 11,200 lbsl day (66,000 - 54,800).
Page 29 OF 37
A-29
The projected 2025 average load is determined as follows:
Projected 2025 BOD = (0.185 x 297,585 x 1.3) + 2,402 = 74,000 mgd (actual calculated value of .
73,971lbsj day rounded to the nearest nundred pounds)
Where:
0.185 is the selected pounds per capita per day (Ppcd) based on dry season
values from 1990 to 2002
297,585 is the projected population to be served in 2025
1.3 is the selected peaking to convert average dry season load to DSMM load
(based on 1990 to 2002 data)
2,402 is the projected industrial flow in Ibsf day (it has been assumed that the
industrial load will remain constant over the study period)
The required capacity to meet the needs of growth in terms of BOD is 19,200 Ibsj day
(74,000 - 54,800).
TSS
The methodology for TSS is identical to that of BOD. The existing capacity, although not
explicitly stated in the current NPDES permit, is 71,600 lbsj day, which was the value used
for the original WPCF design. The current loading or current required, presented in DS:M:M
terms, is 64,700 Ibsj day and is determined as follows:
Current TSS = (0.205 x 217,737 x 1.4) + 2,224 = 64,700 lbsf day (actual calculated value of .
64,715 lbsj day rounded to the nearest hundred pounds)
Where:
0.205 is the selected pounds per capita per day (Ppcd) based on dry season
values from 1990 to 2002
217,737 is the population served in 2002
1.4 is the selected peaking to convert average dry season flow to maximum
month dry season flow (based on 1990 to 2002 data)
2,224 is the current industrial TSS load in Ibsf day J
The available capacity in terms of TSS is 6,900 Ibsj day (71,600 - 64,700).
The projected 2025 average TSS is determined as follows:
Projected 2025 TSS = (0.205 ,., 297,585 * 1.4) + 2,224 = 87,600 mgd (actual calculated value of
87,631 Ibsj day) rounded to the nearest hundred pounds)
Where:
0.205 is the selected pounds per capita per day (Ppcd) based on dry season
values from 1990 to 2002
297,585 is the projected population to be served in 2025
.
Page 30 OF 37
A-30
.
1.4 is the selected peaking to convert average dry season load to D5:MM: load
(based on 1990 to 2002 data)
2,224 is the projected industrial TSS load in lbs/ day (it has been assumed that the
industrial load will remain constant over the study period)
The required capacity to meet the needs of growth in terms of TSS is 22,900 lbs/ day
(87,600 - 64,700).
Biosolids Treatment
The three subcategories used to allocate biosolids treatment, handling, and disposal/reuse
costs for purposes of SDC calculations are:
. General
. Dewatering
. Biocycle farm
Table C-3 presents a capacity summary of the MWMC biosolids facilities.
TABLE C-3
Capacity Summary of MWMC Biosolids Facilities (annual average dry tons per year)
Subcomponents
General Dewatering Biocycle Farm
. Existing capacity 5,869 7,000 2,811
Current loading (current capacity required) 5,869 5,869 2,811
Available capacity None 1,131 None
Available capacity (%) 0% 16.2% 0%
Projected 2025 loading (future capacity required) 8,600 7,000 3,612
Growth loading 2,731 1,131 801
Required Capacity Expansion 2,731 None 801
Growth s.hare of 2025 load 31.8% 16.2% 22.2%
Growth share of capacity expansion 100% 0% 100%
The definition and capacity assessment development for these three subcomponents are
presented in the following paragraphs.
.
General
The general subcomponent consists of biosolids thickening and anaerobic digestion at the
WPCF; the biosoIids pump station/ force main system that conveys digested biosolids from
the WPCF to the BMF; and facultative sludge storage lagoons and drying beds at the remote
Page 31 OF 37
A-31
BMF. The majority of the infrastructure associated with this "General" component was
constructed in the 1980s and early 1990s.
The current loading or current required capacity is presented as annual average dry tons of
digested biosolids. .
Current biosolids loading = 4,962 x 1.183 = 5,869 tons per year
Where:
.
4,962 dry tons per year (actual 2002 value)
1.183 factor to convert actual value to a value that can be directly compared to
the projected 2025 capacity value when a greater biosolids load will be generated
by changes in the treatment process, and is calculated as follows:
= {(60 x 1.23) + (40 x 1.ll)} /100= 1.183
Where:
60 is the weighting given to BOD for biosolids production
1.23 is the BOD ppcd ratio (selected/ actual) calculated as follows:
= 0.185/0.15 = 1.23
Where:
0.185 is the selected annual average BOD ppcd for projected .
influent BOD values
0.15 is th~ actual BOD ppcd (annual average over 12-year
period)
40 is the weighting given to TSS for biosolids production
1.11 is the TSS ppcd ratio (selected/actual) calculated as follows:
= 0.233/0.21 = 1.11
Where:
0:233 is the selected annual average TSS ppcd for projected
influent TSS values (average of dry (0.205) and wet (0.26)
seasonal values)
0.21 is the actual TSS ppcd (annual average over 12-year
period)
Some existing biosolids facilities in the "general" subcomponent have more than 5,869 dry
tons per year of processing capacity while other existing facilities have less. However, in
aggregate there is no available capacity and the existing capacity is assumed to be 5,869 dry
tons per year as well.
The projected 2025 biosolids is 8,600 dry tons per year on an average annual basis. This
value is estimated based on a computer model of the WPCF that predicts biosolids
.
Page 32 OF 37
A-32
.
production among many other parameters. The projected biosolids production in 2025 is
anticipated to increase at a slightly greater rate than the rate of population growth because
of the addition of tertiary filters that will remove additional sonds from the wastewater. The
additional capacity needed to accommodate growth is 2,731 dry tons per year (8,600 -5,869).
Dewatering
MWMC recently installed mechanical biosolids dewatering at the BMF for the purpose of
removing water from the biosolids so that the remaining biosolids volume is reduced. This
dewatering facility was designed to accommodate 7,000 dry tons of biosolids on an annual
average basis. Therefore, the available capacity is 1,131 (7,000 less 5,869). The additional
capacity needed to accommodate growth is 1,131 dry tons per year (7,000 - 5,869).
.
Biocycle Farm
MWMC is in the process of expanding the capability of the biosolids management program
by constructing a poplar plantation or biocyc1e fartn (BF) that can accept non-dewatered
biosolids, therefore limiting dependence on the cooperative farms land application program.
Phase 1 is currently under construction and is slated to be online spring 2004, and it is
assumed that the added flexibility that the Phase 1 BF provides will benefit existing users
only. Phase 1 has a capacity to accept 2,811 dry tons per year. For the purpose of
determining II available capacity" for the purpose of SDC development, it is assumed that
there is no existing available capacity associated with the Phase 1 Biocycle Farm. Phase 2
and 3 will expand the capacity to 3,612 dry tons per year
The additional capacity to meet the needs of growth is 801 dry tons per year (3,612 -2,811)
.
Page 33 OF 37
A-33
... ....
.oJ
.
.
. .
APPENDIXE
GO Bond Credit Calculation
TABLE E.1
GO Bond Credit per $1,000 Assessed Value By Annexation Year
Year of Annexation
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
by Year
$0.09
$0.07
$0.14
$0.18
$0.17
$0.22
$0.33
$0.40
$0.45
$0.49
$0.48
$0.45
$0.21
$0.15
$0.19
$0.17
$0.16
$0.20
$0.24
$0.20
$0.19
$0,05
$0.05
$0.00
$0.00
$0.00
Cumulative Credit (per $1,000 AV)
$5.29
$5.19
$5.12
$4.98
$4.80
$4.63
$4.40
$4.07
$3.67
$3.22
$2.73
$2.25
$1.80
$1.59
$1.45
$1.25
$1.09
$0.92
$0.72
$0.48
$0.28
$0.09
$0.05
$0.00
$0.00
$0.00
* Properties annexed subsequent to debt retirement (2001) not eligible for credit
Page 37 OF 37
FIGURE 2-EXISTlNG SYSTEM ALLOCATION. .
.
NO
~it~lif',
. TABLE 4
Existing System Available Capacity by Parameter
Average Flow Peak Flow BOD TSS
Variable (mgd) (mgd) (Ibs/day) (Ibs/day)
Existing capacity 49.0 175 66,000 71,600
Current loading (current capacity required) 43.8 264 54,800 64,700
Available capacity (value) 5.2 None 11,200 6,900
Available capacity (%) 10.5% 0% 17% 9.6%
Source: 2004 Facilities Plan
.
1 The numbering of the steps for the existing system allocation process is preceded by an "R. to identify these steps as relating
to the Reimbursement Fee calculation, Later processes relating to the Improvement Fee calculation are indicated by an "I" in
the number sequence.
Page 11 OF 37
Step Three - Proiect Valuation
Calculation of the improvement fee beqins with a review of MWMC's adopted 20-Year Proiect
List to determine the value of future proiects. Future proiects are valued based on the inflation
adjusted oriqinal cost estmate approach. Under this approach. the oriqinal estimated cost of
.future proiects is adiusted bv the Enaineerina News-Record national 20-citv averaqe
Construction Cost Index from the time of the ori!::jinal estmate to estimate current values. The
inflation adjusted oriqinal cost estimate approach recoqnizes inflation since the oriqinal
estimate.
.
Step +Rree Four. Project Cost Allocation
The project cost allocation methodology, for use in determining the improvement fee cost
basis, is a four-step allocation process consisting of the following steps:
I-I. Allocate project costs to facility process components (e.g., primary treatment, secondary
treatment).
1-2. Allocate costs by components to system capacity parameters (e.g., average flow, peak
flow).
1-3. Allocate project costs to type (capacity improvement, performance upgrade, or
rehabilitation) .
1-4. Allocate costs to user type (existing customers or projected growth).
The project cost allocation methodology provides an equitable basis for determining the
projects or portions of projects that are related to growth capacity needs and are, thereby,
included in the improvement fee portion of the SOC calculation. The methodology is not
tied to a specific list of projects intended to be funded by SDCs (20-year project list), but is .
intended to provide a consistent framework for allocation of future projects to growth.
Each step of the methodology is described below. The general allocation process is also
presented graphically in Figure 3.
FIGURE 3-PROJECT COST ALLCOATION
.
Page 12 OF 37
.
The allocation of future projects to facility process components is generally fairly
'~';'F'::i;~i~~~~I~j~~~,t:~
.
STEPI-l .. ~
STEPI-2 .. ~
STEPI-3 .. ~
STEPI-4 .. ~
Allocation Basis
.
.
(o/~ '~~i;!i~r~~~i#::!;:'::::
'. ......', ~_.._. ,- '" '" .
;i':J.~.~;J;bfCC~_'i:~~~itY~~;;(~
:i:;.t"~l-~:;~?1~~~~:;'~~~;~~
... ,.... h ...... ..... ',I.,' .
straightforward, as most projects relate directly to an individual component or support the
entire treatment system. The refinement of the facility component allocation process for
MWMC relates to recognition of peak flow management costs. While it is likely that future
project lists will include projects entirely related to peak flow management, it is also likely
that portions of projects relating to various aspects of the treatment process (e.g., secondary
treatment) will also playa role in future peak flow management
The following question needs to be answered when allocating project costs to facility
components: "Which specific facility component does the project expand or improve?" If the
project expands or improves more than one facility component, then project costs should be
apportioned relative to the expansion or improvement of each applicable component
The allocation fractions from Table 3 are used to distribute costs by facility component to
capacity parameter, as was done for the existing system cost allocations. The basis for these
allocations is descnbed in Appendix B.
Step 1-3 of the project cost allocation methodology is to allocate costs to project types. The
three project types, which are intended to be representative of the complete project list, are:
1. Capacity - Projects or portions of projects that are related to increasing liquids and/ or
biosolids conveyance, treatment, and disposition capacity beyond existing design
standards (i.e., projects that provide the next capacity increment within the planning
period).
.
Page 13 OF 37
2. Performance Improvements - Projects that increase system capacity by increasing the
level of performance provided by facilities. Unlike' capacity' projects that relate only to .
the next increment of capacity, performance upg:"ades are generally sized based on total
projected capacity needs at the end of the planning period (existing and future).
3. Rehabilitation - Projects designed to remedy an existing system deficiency and do not
enhance system capacity.
Capacity and performance upgrade projects can be new facilities, or upgrade/ expansion of
existing facilities. Rehabilitation projects are the replacement of outdated or worn out
equipment or facilities.
The majority of the projects will typically fall completely into one project type. However,
some projects may be split between capacity and performance types. The general criteria for
allocating projects to the above categories are shown in Table 5. These criteria should be
applied in the development of specific projects for inclusion in the appropriate planning
document or project list and should be considered and evaluated as part of the process of
adoption of such a plan or project list.
TABLES
Summary of Project Type Allocation Criteria
Project Type
Capacity
Potential Criteria
Adds new facilities/expands existing facilities
Provides new liquids treatment or biosolids capacity beyond existing
system design standard or beyond the current permitted capacity
Adds new facilitieslimproves existing facilities
Provides capacity/enhanced capability sized for total Mure capacity
needs
Driven by new regulatory requirement
Driven by increase in community performance standard
Technological efficiencies
Replaces existing facility or portion of facility
Does not serve growth either through existing available or new
capacity
Preserves existing facility performance/capacity
.
Performance Improvements
Rehabilitation
Once project costs have been allocated to system component and project type categories,
and the costs have been distributed to the system capacity parameters, the final step in the
project cost allocation process is to assign costs to user types. For the purposes of the SOC
methodology, there are two user types: 1) existing customers, and 2) new customers or
growth. Costs that are allocated to growth are incorporated into the SDC improvement fee
calculation. Costs allocated to existing customers must be paid through some other funding
sources (e.g., existing reserves or future user rates).
As indicated in Figure 3, the allocation of project costs to growth is a function of the type of
project and a detailed capacity analysis that identifies growth's share of: 1) planned capacity .-
expansion, and 2) total future load.
Page 14 OF 37
.
Costs by capacity parameter are allocated to growth as follows:
Capacity Projects: Growth's sluzre of capacity expansion (%) X project cost ($)
Perfonnance Upgrades: Growth's sluzre of total future system capacity (%) X project cost ($)
Rehabilitation Projects: Allocation to growth = 0%
Where:
1. Growth's share of capacity expansion = Projected growth capacity requirement (not met
by existing available capacity) divided by additional capacity to be added to the system
by planned improvements.
2. Growth's share of total future system capacity = Projected growth capacity requirement
(total) divided by total future system capacity requirement.
Table 6 summarizes the growth allocation percentages by project type. The documentation
for these figures is provided in Appendix C.
TABLE 6
Growth Allocation Percentages by Project Type
Project Type Average Flow Peak Flow BOD TSS
Capacity (growth's share of capacity 100% 29.4% 100% 100%
expansion)
. Performance (growths share of total 26.1% 10.8% 25.9% 26.1%
future system capacity)
Rehabilitation 0% 0% 0% 0%
Source: 2004 Facilities Plan
Step Four. Adjustments
The methodology includes the following adjustments to the reimbursement and
improvement fee cost bases:
· Gifts or grants from federal or state government or private persons. Existing (and if
applicable in the future, planned) asset costs are reduced by the percent of the asset that
is funded by grants.
· Ratemaking principles employed to finance the capital improvements. Projected
capital financing cost (i.e., interest expense) is added to the cost basis, based on the
recomm~ded project phasing and the need to borrow funds.
.
Methodology Element Three: Develop SDC Schedule
Unit costs for each capacity parameter are determined by dividing the adjusted cost basis by
the projected growth capacity requirements. The unit costs are then multiplied by the
estimated capacity requirements of different types of users, as determined from industry
reference data. Figure 4 illustrates this process.
Page 15 OF 37
FIGURE 4-SDC SCHEDULE DEVELOPMENT
Usin~ industry reference data for charging SDCs is consistent "With the approach MWMC .
has previously used to charge SDCs. This type of approach uses flow and strength
assumptions that are consistent with the system capacity parameters described previously.
For example, average flow is defined as dry season maximum month flow. This capacity
measure is used in estimating user capacity ~equirements. The peak-to-average flow ratio
reflects the system planning assumptions. The flow and strength assumptions for various
land uses (development types) are presented in Appendix D. If information for a particular
develop merit is not found in Appendix D, the SDC will be formulated using average data of
like or similar development as determined by the City Engineer.
Unit Costs
x
x
x
x
Capacity
Requirement /
SD~/Unit
.
Methodology Element Four: Calculate Revenue Offsets and Credits
To comply "With. Oregon SDC law, the SOC methodology must ensure that future system users
contribute ho more than an "equitable share" of the capital costs of existing facilities. Before
real property is developed, it may h,ave been subject to taxes that supported capital funding of
some of the Regional Wastewater System. After a development connects to the system. it will
pay rates and, possibly taxes as well, that may also support some level of capital funding. The
SDC methodology therefore considers past and future payments to be made by new
developments, which may partially fund the same facilities for which the SDCs were paid.
Past Payments
A portion of MWMC's existing facility costs were funded through general obligation (GO)
bonds. The debt service on the bonds was retired through property taxes. Undeveloped land
in the cities of Eugene and Springfield was subject to property taxes, and therefore a GO
bond credit is included in the methodology. The credit is equal to the present value of past
payments on bond principal, expressed in dollars per $1,000 of assessed valuation. The
credit shall accrue from the year of annexation, and be based upon the assessed value of the
real property at the time of application for connection to the system.
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Page 16 OF 37
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Appendix E shows the calculation of the GO bond credit.
Future Payments
The methodology considers whether growth will provide a net contribution .brough
wastewater user fee rates to the cost of capital improvements that benefit existing
customers. If such a contribution is indicated, a credit is provided. The credit is based on a
present-worth analysis, structured as follows:
1. Annual capital costs (adjusted for inflation) associated with 'existing customers' share of
the project list costs (net of rehabilitation costs) are estimated based on the
recommended phasing schedule.
2. The annual capital expenditures are reduced by revenues from reserves and
reimbursement fees to estimate required debt funding
3. Debt services costs are estimated for repayment of borrowed funds
4. Future billing units (average flow and pounds of BOD and TSS) are estimated for the
planning period based on system planning criteria
5. The annual user rate supported debt service per billing unit is determined for the life of
the debt.
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6. The present value of the future stream of rate payments is determined for each year of
the planning period.
A credit amount per unit of capacity is determined based on the year 01 development and
the projected length of future payments.
At the time of adoption of the project list upon which SDCs are to be based, or any periodic
modification to such list, an estimate of project financing costs will be made, based upon the
assumed timing of projects and other available funding sources. The proportion of this debt
financing to be funded by user rates attributable to users estimated to connect in each year is
calculated, and the net present value for each year of the planning period of this series of
cash flows is applied as a credit against the improvement SDC generated by the
methodology.
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Page 17 OF 37
Methodoloqy Element Five: Periodic modification of existinq svtem and future
proiect values
The value of existin~ available capacity and future available capacity may be adjusted from
time to time as stated in Methodology Element Two: Step One and Step Three.
Page 18 OF 37
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APPENDIX D
User Capacity Requirements
TABLE 0-1
Capacity Requirements by User Class
Springfield Dry Season
Traffic/ Eugene Flow Base Flow Average Flow Dry Season Max Wet Season Peak
Wastewater BPRlHUD . Wastewater Estimation Impact Impact Month Impact Flow Impact BODfTSS BOD TSS
Code Code Use Code Type of Establishment Unit (FEU) (gal/FEU/day) (gal/FEU/day) (gal/FEU/day) (gal/FEU/day) . Strength (mgll) Strength (Ib/FEU/day) * (Ib/FEU/day) *
30 4111-4990 4X TRUCK TERMINAL TGSF 100 137 205 398 150 Low 0.171 0.171
151 6371-6379 63 MINI WAREHOUSE TGSF 30 41 61 119 150 Low 0.051 0.051
170 4111-4990 4X UTILITIES TGSF 100 137 205 398 150 Low 0.171 0.171
200 1111-1139 1X OTHER RESIDENTIAL (SFD WIOTHER USES) DU . 175 239 359 696 150 Low 0.299 0.299
220 1130-1139 11 OTHER RESIDENTIAL - MUTI FAMILY . DU 150 205 307 597 150 Low 0.256 0.256
200 1300 ,13 OTHER RESIDENTIAL - RESIDENTIAL HOTEUMOTEL TGSF 200 273 410 796 150 Low 0.342 0.342
240 1400 14 OTHER RESIDENTIAL - MOBILE HOME PARK DU 150 205 307 597 150 Low 0.256 0.256
210 1111-1129 1F SFD I DUPLEX DU 175 239 359 696 150 Low 0.299 0.299
300 1510-1590 15 MOTEL I HOTEL TGSF 200 273 410 796 300 Medium 0.684 0.684
. 400 7212-7900 7X PUBLIC PARK TGSF 160 219 328 636 150 Low 0.274 0.274
435 7X MULTIPURPOSE RECREATION FACILITY (Indoor) TGSF 160 219 328 636 150 Low 0.274 0.274
443 7212-7900 7X THEATER TGSF 160 219 328 636 150 Low 0.274 0.274
488 7X OUTDOOR ATHLETIC COMPLEX TGSF 160 219 328 636 150 Low 0.274 0.274
491 7212-7900 7X TENNIS COURT TGSF 160 219 328 636 150 Low 0.274 0.274
492 7212-7900 7X RACQUET CLUB TGSF 160 219 328 636 150 Low 0.274 0.274
493 7212-7900 7X HEALTH CLUB TGSF 160 219 328 636 150 Low 0.274 0.274
494 7212-7900 7X BOWLING ALLEY TGSF 160 219 328 636 150 Low 0,274 0.274
495 7212-7900 7X RECREATIONAL CENTER TGSF 160 219 328 636 150 Low 0.274 0.274
500 3X INDUSTRIAL PROCESS LOW STRENGTH TGALEF 1000 1,366 2,049 3,978 150 Low 1.710 1.710
500 3X INDUSTRIAL PROCESS MEDIUM STRENGTH TGALEF 1000 1,366 2,049 3,978 300 Medium 3.419 3.419
500 3X INDUSTRIAL PROCESS HIGH STRENGTH TGALEF 1000 1,366 2,049 3,978 500 High 5.699 5.699
500 3X INDUSTRIAL PROCESS VERY HIGH STRENGTH TGALEF 1000 1,366 2,049 3,978 700 Very High 7.979 7.979
500 3X INDUSTRIAL PROCESS SUPER HIGH STRENGTH TGALEF 1000 1,366 2,049 3,978 900 Super High 10.258 10.258
520 6812 68 ELEMENTARY SCHOOL TGSF 50 68 102 199 150 Low 0.085 0.085
522 522 68 MIDDLE SCHOOL TGSF 50 68 102 199 150 Low 0.085 0.085
530 6813 68 HIGH SCHOOL TGSF 50 68 102 199 150. Low 0.085 0.085
540 6821 68 COMMUNITY COLLEGE TGSF 50 68 102 199 150 Low 0.085 0.085
550 6821 68 UNIVERSITY TGSF 50 68 102 199 150 Low 0.085 0.085
560 6911 69 CHURCH TGSF 50 68 102 199 150 Low 0.085 0.085
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. 565 6811-6839, 68 DAY CARE CENTER TGSF 50 68 102 199 150 . Low 0.085 0.085
7111-7123
590 7111 68 LIBRARY TGSF 50 68 102 199 150 Low 0.085 0.085
591 6994 69 FRATERNAL ORGANIZATION TGSF 50 68 102 199 150 Low 0.085 0.085
600 5410-5499. 54 SERVICE STATION I MARKET TGSF 180 246 369 716 150 Low 0.308 0.308
610 6511-6519 65 HOSPITAL TGSF 150 205 307 597 150 Low 0.256 0.256
620 6511-6519 65 NURSING HOME TGSF 150 205 307 597 150 Low 0.256 0.256
630 6511-6519 65 CLINIC, MEDICAL OFFICE TGSF 150 205 307 597 150 Low 0.256 0.256
700 5810 5A FAST FOOD RESTAURANT TGSF ~500 983 1,475 2,864 aoo 700 ~High 4.400 3.989 ~ 3.989
720 8221,8222 82 VETRINARIAN SERVICES TGSF 200 273 410 796 150 Low 0.342 0.342
750 6710-6759 67 OFFICE PARK TGSF 100 137 205 398 150 Low 0.171 0.171
770 6710-6759 67 BUSINESS PARK TGSF 100 137 205 398 150 Low 0.171 0.171
730 6710-6759 67 GOVERNMENT BUILDING TGSF 100 137 205 398 150 Low 0.171 0.171
732 6710-6759 67 US POST OFFICE TGSF 100 137 205 398 150 Low 0.171 0,171
800 5910-5999 59 RETAIL TGSF 50 68 102 199 150 Low 0.085 0.085
831 5810 58 QUALITY RESTAURANT TGSF 72G 500 983 1,475 2,864 aoo 700 ~High 4.400 3.989 4AOO 3,989
832 5810 5C HIGH TURNOVER RESTAURANT. TGSF ~500 983 1,475 2,864 aoo 700 ~High 4,4@ 3,989 4AOO 3,989
EATING PLACE WITH MINIMAL FOOD PREPARATION*** TGSF 300 410 615 1.193 150 Low 0,513 0,513
835 5820 5D DRINKING PLACE WITH MINIMAL FOOD TGSF 340 464 697 1,353 150 Low 0.581 0.581
PREPARATION****
DRINKING PLACE WITH RESTAURANT LIKE FOOD ~ 500 983 1475 2864 700 Very Hiqh 3,989 3,989
PREPARATION
840 6411,6419- 64 AUTO CARE TGSF 40 55 82 159 150 Low 0.068 0.068
. 6499
841 5511-5599 55 NEW CAR SALES TGSF 50 68 102 199 150 Low 0.085 0.085
847 6412 68 CAR WASH TGSF 500 683 1,024 1,989 150 Low 0.855 0.855
848 5511-5599 55 TIRE STORE TGSF 50 68 102 199 150 Low 0.085 0.085
850 5410-5499 54 SUPERMARKET TGSF 180 246 369 716 300 Medium 0.615 0.615
851 5410-5499 54 CONVENIENCE MARKET TGSF 180 246 369 716 150 Low 0.308 0.308
854 5211-5392, 5X DISCOUNT MARKET TGSF 30 41 61 119 150 Low 0.051 0.051
561 0-5733
890 5211-5392, 5X FURNITURE STORE TGSF 30 41 61 119 150 Low 0.051 0.051
561 0-5733
895 7212-7900 7X VIDEO ARCADE I OTHER ENTERTAINMENT TGSF 160 219 328 636 150 Low 0.274 0.274
900 6111-6133 61 FINANCIAL INSTITUTION TGSF 110 150 225 438 150 Low 0.188 0.188
251 1210-1290 128 ELDERLY HOUSING - DETACHED TGSF 100 137 205 398 150 Low 0.171 0.171
252 1210-1290 12A ELDERLY HOUSING - ATTACHED TGSF 100 137 205 398 150 Low 0.171 0.171
253 1210-1290 12C CONGREGATE ELDERLY CARE FACILITY TGSF 100 137 205 398 150 Low 0.171 0.171
120 2111-2190 21 HEAVY INDUSTRYIINDUSTRIAL ** TGSF 50 68 102 199 150 Low 0.085 0.085
120 2220-2395, 2X HEAVY INDUSTRYIINDUSTRIAL** TGSF 50 68 102 199 150 Low 0.085 0.085
2510-2790
120 2400,2421- 24 HEAVY INDUSTRYIINDUSTRIAL ** TGSF 50 68 102 199 150 Low 0,085 0.085
2499
120 2810-3999 3X HEA VY INDUSTRY/INDUSTRIAL ** TGSF fJ 68 102 199 150 Low 0,085 0.085
120 2810-3999 3X HEAVY INDUSTRYIINDUSTRIAU WHOLESALE** TGSF 50 68 102 199 150 Low 0.085 0.085
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. 710 6141-6190, 6X GENERAL OFFICE SLOG TGSF 100 137 205 398 150 Low 0.171 0.171
6500, 6520-
6599,6810
860 5111-5199 51 WHOLESALE TRADE TGSF 50 68 102 199 150 Low 0.085 0.085
870 5211-5392 5X CLOTHING / DRYGOODS / HOUSEWARES TGSF 30 41 61 119 150 Low 0.051 0,051
820 6211-6215 6A LAUNDRY TGSF 100 137 205 398 150 low 0.171 0.171
900 6212-6290 62 OTHER SERVICES TGSF 100 137 205 398 150 low 0.171 0.171
110 6611-6629 66 CONSTRUCTION TRADE TGSF 100 137 205 398 150 Low 0.171 0.171
440 6811-6839 68 OTHER EDUCA TIONAUCUL TURAl TGSF 50 68 . 102 199 150 Low 0.085 0.085
450 7212-7900 7X OTHER ENrERTAINMENT TGSF 160 219 328 636 150 low 0.276 0.276
820 SHOPPING CENTER TGSF 100 137 205 398 150 low 0.171 0,171
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A88REVlA TJONS
TGSF - THOUSAND GROSS SQUARE FEET
TSFGLA - THOUSAND SQUARE FEET GROSS lEASABLE
AREA
DU - DWELLING UNIT
TGALEF - THOUSAND GALLONS ESTIMATED FLOW
VFP - VEHICLE FUELING POSITIONS
Notes:
*Calculated as average flow (galluniVday)/1 ,000,000 X 8.345 X strength (mglJ).
-Process flow is in addition to other flow.
*** Minimal food re aration - food is assembled from re acka ed food roducts and cookin
**** Includes coffe houses and iuice bars where appropriate.
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