HomeMy WebLinkAboutMiscellaneous Miscellaneous 5/6/2004
Summary of Major Findings Important to Phase 2
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The following are the major findings of Phase 1 that were deferred to Phase 2, Long-Term
Impr~)Vements, for further evaluation and planning:
.' The remaining treatment capacity of the E/SWpeF is substantial for average dry and
wet weather flow conditions and conventional pollutants (BOD, and TSS),
. Peak flows have approached Or exceeded the hydraulic design capacity of the plant in
seven instances, but no NPDES permit violations have occurred-mass limits have been
suspended in these instances. Flows greater than the peak design capacity have been
pumped by relying on redundant, spare pumps. The frequency of'peak flow
exceedances will increase as the base, average wastewater flow increases_ This could
potentially lead to NPDES permit violations caused by sanitary sewer overflows or
exceedance of effluent quality permit limits,
. The biosolids management facility has insufficient capacity to process solids currently
produced by the E/SWrCF,The facultative slUdge lagoons will be full in 3 to 5 years_
Each of t!lese findings are addressed in Phase 2 of the master plan,
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Date Received
MAY 0 6 Ii
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450.
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Table 3-3
Design eriteria,!nd Historical Averages
01'iginal Design eriteria '
Parameter
A verage Dry
Weather
Average
Annual
Maximum Day
Average Wet
Weather
Flow (mgd) 49 70 59.5
, BODs (Ib/day) NA NA 66,000
i
! TSS (Ib/day) NA NA 71,600
I Historical Average lnfluej,t Flow and Loads 1990 through 1995
79,000
92,000
Percent of
Parameter A verage Dry Average Wet Average Maximum ' Design
Weather Weather . Annual' Month (Ave, Annual)
i Flow (mgd) 26,0 41.8 340 73.5 57%
BOD, (lb/day) 28,682 30,644 30,105 , 59,593 46%
i TSS (lb/day) 31,056 36,684 34,063 65,822 48%
i Note: In October 1992, thecE/SWPCF laboratory staff converted from BOD, to CBOD, for plant influent
i analysis. .
=NA = Notapl'licable
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455.
Date Received
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Table 3-4
Average Per Capjta_Loadi"gs
I Desig" Criteria
177
--,
'I' Dry weather flow (gallons per capita
1 per day)
Actual Loading
143.,
i Wet weather /low (gallons per capita
'I per day)
I BOD (pounds per capita' per day)
I TSS (pounds per capita per day)
253
243
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0,24
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L_~.
0,17
1~
0,26
0.19
The fact that the plant is receiving average flows and loads at about half of its design
capacity can be attrib"ted to the slow population growth during the 1980s and lower than
anticipated per capita pollutant loadings.
Based on LeOC's data for projected population growth through 2015 and existing influent
per capita loadings, the facility's remai"ing useful life in years, as measured by the facility's
design capacity being reached, is presented in Table 3,5 and is shown graphically in
Figures 3-2 through 3-6, Flow projections shown include 2,6 mgd to account for two major
high_volume wastewater dischargers currently under construction. The projections are also
based on the assumption thatthe Santa Clara/River Road area will be fully sewered by year
2000. A brief discussion of each figure follows:
. Figure 3-2, Wet Weather Flow: Beyond 1996, the projection is based on the average per
capita wet weather flow for the past 6 years and LCOG'.s population projection, The
maximum month flow (MMWWF) is based on the historical peaking factor of 1.34. The
generally accepted maximum month design criterion for secondary clarifier overflow
rates is 600 'to 800 gallons per day per square foot (gpd/ft'), which for the eight 130-foot-
diameter secondary clarifiers equates to a MMWWF range of 64 to 85 mgd, The
projected MMWWF intersects 85 mgd, the flow rate corresponding to an over flow rate
of 800 gpd/ ft', in about year 2007. If not for the ability to provide split stream treatment
(the diversion of flows in excess of i03 mgd around the secondary process), an overflow
rate of 800 gpd/ ft' might well be considered too high, The MMWWF is the controlling
parameter that will limit the liquid process capacity and drive the need for secondary
treatment improvements. The MMWWF is highly influenced by collection system
infiltration and inflow and is closely interrelated with the E/SWpeF peak hydraulic
flows discussed later,
.
Figure 3-3, Dry Weather Flow: Again, dry weather flow projections are extrapolated
from historical per capita dry weather flows and LeOG population projecti'ons, The dry
weather average to maximum month flow peaking factor is 1.34, Ample dry weather
capacity remains well beyond the current LCOG planning horizon, The dry weather
maximum month flow projection intersects the maximum month design criteria of 66
mgd at about year 2024, The eight 13D-foot secondary clarifiers would result in an
overflow rate of 621 gpd/ ft2, within the acceptable range, Date Received
Mt.'t'MCO fiP~oli\3~
3-6
Planner: BJ
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pox1nAA.()(X
456,
Table 3"5
Remaining Life of E/SWPCF
____ Based on 6 )'ears of Data,.!290 t~rough 1995
- --- 1------ Remaining Life in Years
Flow' BOD. I
18 NA
,
,\
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f=-----
Wet Weather
Monthly Average
Wet Weather _
~ Maximum Month
i Dry Weather
i Monthly Average
Dry Weather
Maximum Month
Monthly Average
Maximum Month
10
NA
30
NA
27
NA
) NA I
L NA I
---.---~--
40
33
. Years of life remaining includes allowance for two major industrial developments
underway, "
NA = not applicable.
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LIFE-DOC
457,
Date Received
MAY 06 I ()~
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Date Received
MAY 06(0.(
Planner: B~j
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\ . Wet Weather
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.. Management
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Metropolitan Wastewater Management Commission
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partners in wastewater management.
1453.
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Executive Summary
Introduction
In late 1997, the Metropolitan Wastewater Management Commission (MWMC) initiated a
project to develop a comprehensive Wet Weather Flow Management Plan (WWFMP or "the
plan") for the wastewater collection and treatment facilities in the Eugene/Springfield.
Oregon, metropolitan area, The need and scope of the project arose from recommendations
in the Eugene/Springfield Water Pollution Control Facility Facilities Master Plan and results
of preliminary analysis using a hydraulic model deve!oped for the regional wastewater'
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co ection system, ' "
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The treatment plant was designed in the 1970s to proyideadequate capacity through 2005,
From a base flow and loading standpoint, the treatm~nt plant performs well within its
capacity (49 million gallons per day [mgdJ) in dry-weather months, However, winter
rainfall creates flows to the treatment plant that excee'd the plant's peak capacity (175 mgd)
on average several times per year and e;'ceed full (secondary) treatment capacity (104 mgd)
more frequently, Figure ES-l shows seasonal average:wastewater flows into the treatment
plant and compares them to peak wet weather flows from a typical storm event. A portion
of the flows that exceeds the full (secondary) treatment capacity (104 mgd) receive primary
treatment only and are mixed with fully treated water before being released to the
Willamette River,
USRlOO3672J3O,OOC
Peak flow estimates for conditions associated with the 5-year storm event are used to size
and plan for future system improvements at the trealInent plant and in the collection
system, Through system modeling, the 5-year peak was estimated at 264 mgd, Peak flows
are attributed to high infiltration and inflow (I/l) rates in many areas of the collection
system. 1/1 occurs from extraneous water getting into,the system from illegal roof drain
connections, Sewer pipe cracks, and other sources.lj1"is often associated with older pipes in
the system that have deteriorated. Sanitary pipes in older areas are also more likely to be
subject to improper storm drainage (inflow) connecti~ns whenconslI'uction inspection
practices were more lenient and/ or such connections were allowed, Creating a combined
flow'system, Newer pipe systems reflect improvements in constru<;tion techniques,
materials, and inspection and typically exhibit far lessI/I. In Eugene, 11 percent of the pipes
are at least 50 years old, In Springfield, the percentag~ of pipes at least 50 years old is
15 percent. Because the priinary sources of IjI are in the existing system and limited Ijtis '
anticipated,from ~ystem expansion, growth in the system does not contribute significantly
to projected system deficiencies, The 5-year peak is estimated af298 mgd, Of this peak,only
4 percent, or 12 mgd, is estimated to be the result of 1/1 from future pipes.
Estimates'1Ilade at the time of design of the treahne~tplant, relative to the amount of
rainfall-derived infiltration and inflow (RDII) that could be cost-effectively removed, were
overly optimistic, This has resulted in insufficient capacity to manage peak flows at the
treatment plant and has increased the risk of sanitary sewer overflows (SSOs) at~C'l ' d
locations in the collection system. Example problems ihcIude basement and stre.!t.ItMI:It1f;\~CeIVe
MAY 0 6 1 d
MWMC-00001~ '1465,. q fi
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WET WEATHER flOW JMNAGa.ENT f'I..AH
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and discharges to stormwater facilities and receiving waters. Although the magnitude of
wet weather flows differs greatly, they are significantly diluted because the source of a
majority of the flow is rainwater, not sanitary sewage, Treatment plant flow data indicates
that wet weather flow is diluted such that the concentration of typical pollutants in wet
weather flow is 50 percent to 60 percent of that in dry weather flow,
FIGURE ES-l
Seasonal Measured Rows' at !he Wastewater Treatment Plant
Seasonal Measured Flows at the Wastewater Treabnent Plant
200
180
160
~ 140 L-- __ __ __ _ _.,.R_e~~9fI~~_S_~~~~'Y!':.e~~=~t_L!'!..e~.:'.,,-___
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Average Summer AaNS
Average Wll'ller ReNts
1999.2CO.l Peak Winter Flows
during storm EYents
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The overall objective of the plan is to determine the most co,st-effective and politically
feasible method to manage peak wet weather wastewater flows that is acceptable to the
Eugene and Springfield commwlities.
Summary of WWFMP
Developing the plan essentially consisted of evaluating four technologies for managing
excess wet, weather flow relative to performance (frequency, of SSOs), cost, and political and
community acceptance, The Jour technologies included: (l){system rehabilitation to control
RDll; (2) in-line and off-line storage of peak flows; (3) additional conveyance (including
greater pipe conveyance and pump station capacity); and (4) additional capacity to treat
peak flows at the treatment plant '
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MAY 06 {O~ '
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Average Monthly Residential Sewer Usage
7.0
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Fye9/90 FY90/91 FY91/92 FY92/93 FY93/94 FY94/95 FY95/96 FY96/97 FY97/98 FY98/99 f'Y99/00
Fiscal Year
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t:.:/srage Monthry'Residentia! Usage 1.000 gal
Fiscal Year Eugene 'Springfield Regional
FY39!90 5,8 6,2 6.0
FY90/91 5.5 6,3 5.9
F'/91/92 5,5 6.1 5,8
FY92J93 5.5 6,0 5,7
FY93/94 .5.6 5A 55
FY94/95 5A 5A 5A
FY95/96 5,2 5,3 53
FY96/97 5,1 5,2 5,2
FY97/98 5.2 5,2 5,2
FY98/99 5,0 5.2 5,1
FY99100 50 5,0 5.0
FYOOIO 1 49 4.9 4,9
FY01/02 4,6 4,8 4,7
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Date Received
MAY v 6 I Oq- ,
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Technical Background, Report:
ExistingCol"lditions
and Alternatives
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Eugene-Springfield Metropolitan Area
Public Facilities and Services Plan
April 19~9
Date Received
MAY 0 6 I o~
Planne~~7,BJ
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Regional Wastewater Treatment System Condition Assessment
Regional Wastewater Treatment System Capacity
The MWMC Master PlanJor the Eugene-Springfield Water Pol/ution Control Facility, (Master
Plan), completed in 1997, provides a comprehensive evaluation of the facility. The Master Plan
estimates a fully sewered population within the metropolitan UGB to reach 402,567 by 2040,
with a regional population of 443,033 receiving wastewater service at full build-out in 2050,
The Master Plan estimates that existing design capacity of the, treatment plant can serve all new
development in the metropolitan area through at least the year 2020, However, peak wet weather
conditions that cause large yolumes of stonnwater to enter the wastewater collection system ,
constrain the plant from achieving its designed capacity, Wet weather related improvements are
needed at the plant and within the collection system to extend the plant's wet weather capacity
beyond the year 2007,
The treatment plant, which officially began operation in April 1984, replaced the separate plants
previously owned and operated by Eugene and Springfield, At the time of construction, the
capacity of the plant was projected,to serve the growing metropolitan area'for a period of20
years. However, slower than anticipated growth in the 1980s has extended the design life of the
plant by at least 15 years,
The regional Biosolids Management Facility was designed to match biosolids drying and land
application to the volume produced by the wastewater treatment plant. However, lower than
anticipated solids processing efficiency (primarily due to variable summer weather conditions) is
requiring additional improvements at the facility in order to match the design capacity of the
treatment plant.
The treatment plant has a dry weather design capacity of 49 mgd, Current actual dry weather,
flows range from 45 percent to 57 percent of the design capacity, Sufficient treatment capacity
exists to meet projected growth throughout the PFSP planning horizon. However, peak wet
weather volume of flow, not influent wastewater characteristics, currently constrains the life span
of the plant's design capacity. The plant has a wet weather design capacity of 175 mgd, Current
maximum monthly wet weather flows reach 85 percent of.the design capacity for flow, High
levels of wet weather flows are generated by infiltration and inflow (Ill) of stonnwater into the
sanitary sewer system, Infiltration is a process by which groundwater enters the system through
cracks and joints in sewer pipes. Inflow is the process by which stonnwater enters the system
through improper connections of roof drains and other stoimdrainage facilities to the sanitary
sewers, and by surface runoff entering through manholes."
Regional Wastewater Treatment Facilities eondition Assessment
The physical condition of the regional wastewater treatment facilities is maintained through
equipment replacement programs and major rehabilitation programs funded by MWMC to
maintain and extend the life of major regional wastewater ~ollection and treatment infrastructure.
eurrent physical conditions with planned future equipment replacements and ongoing
, '
19
Date Received
MAY 1I 6 I of
Planner:I~",,~
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rehabilitation projects will maintain all regional wastewaterfacilities in good working order for
the duration of the PFSP planning period, '
eompliance with regulatory parameters is a good indicator:of facility conditions, The treatment
plant has always operated in compliance with its National Pollutant Discharge Elimination
System (NPDES) permit during wet weather conditions, J:he mismatch of wet and dry weather
treatment plant design is due to the fact that the amount ofI/I targeted for removal through
collection system rehabilitation to match the wet weather hydraulic capacity has not been
achieved. To address this issue, MWMC, Eugene and Springfield are developing a Wet Weather
Flow Management Plan (WWFMP) to determine the optimal mix of treatment plant and
collection system rehabilitation improvements. Recommended improvements will be
incorporated into MWMC, Eugene and Springfield Capital Improvement Programs to extend the
wet weather capability ofthe system.
Since 1990, the amount of sludge produced by the Biosolids Management Facility has exceeded
the process capacity ofihe faciljty's drying beds. This has:occuITed because two drying cycles
per year are necessary to keep pace with production. Freq\lently, summer rains prevent two
cycles from being achieved" Expansion of the facility's de~atering capacity is needed to extend
the capacity of the lagoons beyond the year 2000, MWMe is cUITently completing
designsiengineering, and will construct a mechanical dewatering facility in 1999/2000 that will
eliminate the biosolids processing capacity constraint.
The condition ofbiosolids quality is excellent, and consistently meets or exceeds all federal
standards. No degradation ofbiosolids quality is anticipated over the PFSP planning period,
Eugene Wastewater System Inventory amI Assessment
Eugene Wastewater System Inventory
Map 7 shows the existing wastewater system basins in Eugene, the Regional Wastewater
Treatment Plant (treatment plant), existing pipes 24 inches:'or greater in diameter. and the eight
inch line to the Eugene Airport, '
As of 1998, the wastewater collection system totaled 607 miles in length, with over 20 miles of
I
pressure lines, The collection system consists of 433 miles of eight-inch pipe, and 46 miles of
pipe 24 inches or greater in diameter. There are five main follection system areas (system areas)
within Eugene's service area, each of which is divided into' basins, as follows,'
,
I, eentralEugene:
'f
Downtown Westside, D.owntown eentral, Downtown Amazon, and
Downtown Franklin basins '
Willakenzie North and South and WillametteRiver basins
Bethel-Danebo North and South basins
Glenwood and Lane eommuriity eollege basins
River Road, Santa elara and Highway 99 basins
2, Willakenzie:
3. Bethel-Danebo:
4. Southeast Eugene:
5. River J3,oad:
20
Date Received
MAY 06, at{
1187,
Planner: BJ
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Date Received,
MAY \J BIOf
Planner~ 8 ~
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Oregon's Statewide Planning Goals & Guidelines
GOAL 6: AIR, WATERAND LAND
RESOURCES QUALITY
OAR 660-015-0000(6)
To maintain and improve the quality
of the air, water. and land resources
of the state.
All waste and process discharges
from future development, when
combined with such discharges from
existing developments shall not threaten
to violate, or violate applicable state or
federal environmental quality statutes,
rules and standards, With respect to the
air, water and land resources of the
applicable air sheds and river basins
described or included in state
environmental quality statutes, rules,
standards and implementation plans,
such discharges shall not (1) exceed the
carrying capacity of such resources,
considering long range needs; (2)
degrade such resources; or (3) threaten
the availability of such resources.
Waste and Process Discharges --
refers to solid waste, ,thermal, noise.
atmospheric or water pollutants.
contaminants. or products therefrom.
Included here also are indirect sources
of air pollution which result in emissions
of air contaminants for which the state
has established standards,
GUIDELINES
A. PLANNING
1. Plans should designate
alternative areas suitable for use in
controlling pollution including but riot
limited to waste water treatment plants,
solid waste disposal sites and sludge
disposal sites,
2. Plans should designate areas
for urban and rural residential use only
where approvable sewage disposal
alternatives have been clearly identified
in such plans,
3, Plans should buffer and
separate those land uses which create
or lead to conflicting requirements and
impacts upon the air, water and land
resources,
i 4, Plans which provide for the
maintenance and improvement of air.
land ,and water resources of the
planning area should consider as a
major determinant,.the carrying capacity
of the air; land and water resources of
the planning area, .The land
conservation and development actions
provided for by such plans should not
exceed the carrying capacity of such
resources.
I 5. All plans and programs
affecting waste and process discharges
should be coordinated within the
applicable air sheds and river basins
des~ribed or included in state
environmental quality statutes. rules,
stanaards and implementation plan,
6, Plans of state agencies before
they .are adopted should be coordinated
with and reviewed by local agencies
with respect to the impact of these plans
on the air. water and land resources in
the planning area,
1
Date Received
MAY 0 6 of
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Planner: BJ
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7, In all air quality maintenance
areas, plans should be based on
applicable state rules for reducing
indirect pollution and be sufficiently
comprehensive to include major
transportation, industrial, institutional,
commercial recreational and
governmental developments and
facilities.
B.IMPLEMENTATION
1, Plans should take into account
methods and devices for implementing
this goal, including but not limited to the
following:
(1) tax incentives and
disincentives,
(2) land use controls and
ordinances.
(3) multiple-use and joint
development practices,
(4) capital facility programming,
(5) fee and less-than-fee
acquisition techniques, and
(6) enforcement of local health
and safety ordinances.
2, A management program that
details the respective implementation
roles and responsibilities for carrying out
this goal in the planning area should be
established in the comprehensive plan,
3. Programs should manage land
conservation and development activities
in a manner that accurately reflects the
community's desires for a quality
environment and a healthy economy
and is consistent with state
environmental quality statutes, rules,
standards and implementation plans.
, ,
2
Date Received
MAY 0 6 lor
Planner: e;"J