HomeMy WebLinkAbout12. Approve Electric Blower Improvements Project - Phase 1 and funding the Steam and Aeration Blower Systems Renos, DP 7349, etc. Page 1 of 17
Item 12.
CENTRAL SAN BOARD OF DIRECTORS
POSITION PAPER
MEETING DATE: JULY 16, 2020
SUBJECT: APPROVE THE ELECTRIC BLOWER IMPROVEMENTS PROJECT -
PHASE 1 IN THE FISCAL YEAR 2020-21 BUDGETAND FUNDING FROM
THE STEAM AND AERATION BLOWER SYSTEMS RENOVATIONS,
DISTRICT PROJECT 7349; AND AMEND AN EXISTING PROFESSIONAL
ENGINEERING SERVICES AGREEMENT WITH HDR, INC. IN AN AMOUNT
NOT TO EXCEED $880,000 TO INCLUDE FINAL DESIGN SERVICES,
INCREASING THE AGREEMENT COST CEILING TO $3,470,000
SUBMITTED BY: INITIATING DEPARTMENT:
NITIN GOEL, SENIOR ENGINEER, SPECIAL ENGINEERING AND TECHNICAL SERVICES-
PROJECTS AND ASSET MANAGEMENT PDS-ASSET MANAGEMENT
REVIEWED BY: DANEA GEMMELL, PLANNING AND DEVELOPMENT SERVICES DIVISION
MANAGER
EDGAR J. LOPEZ, CAPITAL PROJECTS DIVISION MANAGER
JEAN-MARC PETIT, DIRECTOR OF ENGINEERING AND TECHNICAL
SERVICES
Roger S. Bailey
General Manager
ISSUE
The Board of Directors (Board) authorization is required for the General Manager to amend an existing
professional engineering services agreement in an amount greater than $200,000.
BACKGROUND
Central San staff has updated the Board or Board Committee at several meetings, including on December
20, 2018, when the authorization was granted to enter into an agreement with HDR, I nc. (HDR)for
condition assessment and preliminary design of the Steam and Aeration Blower Systems Renovations,
July 16, 2020 Regular Board Meeting Agenda Packet- Page 352 of 393 Amended Agenda
Page 2 of 17
District Project (DP) 7349 (Steam Project). This decision was made after a very competitive and formal
Request for Proposal (RFP) process that included four qualified consulting engineering firms. The RFP
scope of work included preliminary, final design services, and engineering services during construction for
an estimated total Steam Project budget of$63 million. Staff is now recommending phasing the Steam
Project into five distinct projects and proceeding with final design of the Electric Blower Improvements
(Phase 1 of the Steam Project).
Aeration Blowers
The aeration blowers supply air to four aeration basins, pre-aeration system, final effluent, and mixed liquor
channels. Central San has three aeration blowers (blowers). Two blowers, installed in 1974, are steam-
driven turbine blowers utilizing steam produced from the heat recovery from the furnace's waste heat
boilers, cogeneration system, and augmented by auxiliary boilers. The steam-driven blowers are
oversized, each rated at 71,000 standard cubic feet per minute (scfm), for the treatment plant's (plant)
typical operation which typically uses on average 30,000 and 45,000 scfm. In addition, there is complex
interconnection between the solids process, waste heat, steam-driven blower, and the secondary process
aeration system. Due to this complex interconnection, any upsets, shutdowns, and process variability in
any of these systems can potentially impact the plant's ability to meet the dissolved oxygen needs of the
biological process and impacts the furnace air scrubber emission system.
The electric blower, which is the third blower, serves as a backup when the steam system is shut down for
maintenance or under emergency scenarios. However, there are several shortcomings associated with the
electric blower. The findings of the condition assessment and capacity analysis are that the single existing
electric blower does not provide adequate redundancy(only produce air up to 30,000 scfm)to meet peak
aeration demand (over 70,000 scfm). The electric blower is challenging to operate with the standby power
generation system due to the high in-rush current of the 2,000 horsepower electric motor, has limited
turndown capabilities because it has a synchronous motor with no variable frequency drive, and cannot be
operated in parallel with the larger steam turbine blower(controls and blower curve issues).
In summary, there are several vulnerabilities associated with the three blowers including its complexity
(steam system and controls), inability to operate in parallel (only one of three blowers can operate at a
time), limited air flow output turndown (on both the steam and electric blowers), and a lack of redundancy.
The rehabilitation or replacement of the existing electric blower and addition of a new electrical blower(s) is
now of critical importance to Central San because the plant would have insufficient process air and steam
production during the construction of the Solids Handling Facility Improvements Project, DP 7348 (Solids
Project) as explained in further sections. Insufficient process air over a prolonged period could result in
National Pollutant Discharge Elimination System (NPDES) Permit compliance issues resulting from the
biological treatment process upsets.
Steam Project Long Alternatives
Looking into the future, Central San is faced with the critical decision of whether to continue operating the
existing complex steam system that provides the steam required to power the turbines that drive the two
large aeration blowers (with back-up electric driven blowers), or transition towards the use of modern
technology using steam for electric power generators and convert the aeration blowers to all electric. The
evaluation aims to address both the short- and long-term impacts of this question based on preliminary
findings from the on-going Steam Project.
For the long-term, the solution to this problem is governed by Central San's overall drivers: i) aging
infrastructure, ii) performance analysis/sustainability, iii) capacity, and iv) regulatory. For the short-term
(defined as the next 3-5 years during the Solids Project construction), the problem is the ability to provide
sufficient process air during this period to meet NPDES limits. The two long-term alternatives that are
being evaluated as part of the Steam Project will both continue to rely on our existing heat recovery units
(cogeneration boiler, waste heat boilers from the furnaces, and auxiliary boilers). One alternative would
continue to operate the existing steam blowers with standby electric blowers (current approach)or convert
July 16, 2020 Regular Board Meeting Agenda Packet- Page 353 of 393
Page 3 of 17
to all electric-driven blowers and install steam power generators in the Solids Conditioning Building (SCB)
to produce electricity from the steam.
One common element to both long-term alternatives is the addition of electric driven blowers to meet the
above-mentioned drivers. The addition of new electric blowers will enable the aeration blower system to
meet the variable air demand, reliability, and redundancy needed at the plant and especially under
emergency scenarios. New electric blowers would have a much better turndown (larger range between low
and high air output). This would help avoid air wasting during periods of low demand.
Impact of Solids Project with the Steam Project— Short-Term Alternatives
Central San is nearing completion of the final design for the Solids Project, with construction slated to
begin in the Spring of 2021. During the construction of the Solids Project, several unit processes located
inside the SCB will need to be offline for an extended period (several months and maybe possibly up to
one year)to facilitate construction sequencing, reduced risk of unplanned shut downs, and improve safety
for staff and the contractor.As part of two comprehensive Solids Project workshops that took place on
January 29-30, 2020 and April 9, 2020, which included the Solids Project's design consultant(Black and
Veatch) and construction management firm (MW H Constructors), Steam Project consultant (HDR) and
Central San staff, there were extensive discussions on "what-if" scenarios about shutting down the SCB
and all equipment to allow the contractor full unrestricted and unconstrained access and facilitate
construction. Following the discussion, it was concluded that Central San should continue to operate the
cogeneration system to produce electricity and use natural gas (NG). It was also agreed to keep the two
auxiliary boilers operational (one fueled landfill gas and another using NG, if needed)to continue producing
steam. These fuel demands will satisfy Central San's contractual commitments for the purchase of these
two gas fueled sources. However, an option for the furnaces and associated equipment(e.g., wet
scrubbers, waste heat boilers, and ash handling) be taken offline during the part of the construction and
during the retrofits of these unit processes is being considered and included in the bid documents to
address safety concerns, coordination issues, and to facilitate the construction sequencing being planned.
Shutting down the furnaces and associated waste heat boilers will reduce the total steam amount
generated during construction of the Solids Project. While they will be sufficient steam to drive the blowers
during average diurnal air demand, there will be insufficient steam to drive the turbines at full load. This will
lower the air production capacity in the steam-driven blowers during the peak aeration demands.
Therefore, additional air production will be required from the new electric blowers. During the Solids
Project, both steam and PG&E electricity will be used for the blowers to produce process air. Under an
eventual Public Safety Power Shutoff by P&G E, the new electric blowers can be powered using the
existing two 2-Megawatt electric standby generator that could supply power even if sufficient steam is not
available during that time.
Therefore, subsequent to these workshops, HDR was tasked to develop alternatives to address the steam
and air production issues during construction of the Solids Project.
Business Case Evaluations (BCEs)
HDR prepared several BCEs that evaluated blower combinations to provide adequate redundancy and
reliability during the Solids Project construction and have long-term benefits.Apart from the capacity
deficiency to meet the peak aeration demands with the steam driven blowers during the Solids Project
construction, the biggest drawback is that Central San would be relying on steam production which is
susceptible to multiple outages during the upcoming Solids Project construction (projected to last over
three years).As stated above, the existing electric blower does not provide enough firm capacity(about
half)to meet the peak aeration demands.
Based on HDR's detailed alternative evaluations and BCEs, staff determined that installing two new
electric blowers would provide a means to address the short-term challenge during construction of the
Solids Project, and provide a long-term benefit of improved performance (efficiencies, redundancy, and
reliability).
July 16, 2020 Regular Board Meeting Agenda Packet- Page 354 of 393
Page 4 of 17
When evaluating the long-term needs of the Steam Project, staff is recommending implementing the
improvements over time and in several phases when needed. A similar approach was recently taken for the
Filter Plant and Clearwell I mprovements - Phase 1 A Project to manage the construction and capital
expenditures. The Steam Project Implementation Plan, while not yet completed, outlined in the phases
takes into consideration other project needs, such as future regional cooperation (Water Exchange) and
regulatory driver such as future nutrient removal (as part of future Watershed Nutrient Permit
requirements). The preliminary phasing of the project is outlined below and will be updated when the
summary of findings is finalized later this year.
• Phase 1: Electric Blower Improvements -Add new electric blowers in the Pump and Blower
Building, with dedicated small blowers for channel aeration, and includes associated electrical and
controls systems.
• Phase 2: Secondary Process Improvements including aeration basins, diffusers, associated
electrical and controls systems, mixed liquor division box, and secondary clarifiers with associated
pumping equipment.
• Phase 3: Complete evaluation of the steam system and determine whether to upgrade the existing
steam system versus conversion to all electric blowers with the Steam Turbine Power Generator.
The recommended solution would be implemented under that phase and would include updating the
remaining blower improvements accordingly.
• Phase 4: Rehabilitation or addition of other elements that will be impacted if a Water Exchange
Project was to proceed.
• Phase 5: Modifications and additions for future nutrient removal.
Staff evaluated all results of the BCEs to reach consensus on the preferred alternative which is now
recommended as Electric Blower Improvements. The conclusion of the BCE provides justification for the
recommended alternative, which demonstrates how the recommended solution provides the best overall
value for Central San ratepayers and the community when considering level of service, economic factors,
risk, and intangible factors.
Electric Blower Improvements - Phase 1 Approach
Staff is recommending proceeding with design of the Electric Blower Improvements and include the
following main elements:
• Refurbish and add new electric blowers in the Pump and Blower Building.
• Add dedicated small blowers for pre-aeration, mixed liquor, and final effluent channel air mixing.
• Add associated electrical instrumentation and controls systems improvements to support process
renovations.
A summary of the long-term benefits from the Electric Blower Improvements is described below:
• Recommended under both long-term alternatives of the Steam Project;
• Provides reliable air supply redundancy after the construction of the Solids Project is complete due
to steam supply outages (e.g., during the cogeneration system annual maintenance);
• Ability to perform aeration header inspection and repairs (an asset that is fundamental to the plant):
once new electric blowers are installed, and new aeration header valves are installed, the plant would
have adequate header capacity perform inspection and repairs;
• Ability to address the well-documented process air leaks and have a system in place that can
accommodate a reduction in airflow demands (existing steam-driven blowers could potentially surge
after addressing leaks); and
• Electric blowers are the industry standard, are less complex, and require significantly less
maintenance compared to steam blowers.
July 16, 2020 Regular Board Meeting Agenda Packet- Page 355 of 393
Page 5 of 17
ALTERNATIVES/CONSIDERATIONS
This project was reviewed in detail by the Capital Improvements Executive Review Committee on June
29, 2020, which includes the General Manager, Executive Management, Engineering staff, and key
representatives from Operations and Maintenance.
The Board could consider several alternatives for the Phase 1 Blower Project, as follows:
• Alternative 1: Status Quo - Do Nothing Alternative, which would impact the Solids Project by limiting
the furnace shut down options and increasing construction risk.
• Alternative 2: 1 nclude or combine the Phase 1 Blower Project with the Solids Project. Staff has
considered this alternative, but the Solids Project is expected to bid later this calendar year. This
alternative could delay bidding of the Solids Project into 2021.
• Alternative 3: 1 nstall temporary blower systems to achieve the air demand needed for the Steam and
Solids Projects, which adds significant costs.
These alternatives are not recommended.
FINANCIAL IMPACTS
The total anticipated cost for the final design of the Electric Blower Improvements is $880,000, which
includes final design and bidding services performed by HDR. The total estimated construction cost is
$9,200,000, which equates to roughly 9.6% design fee for HDR. The cost ceiling of HDR's current Steam
Project contract is $2,590,000. If the Board approves the final design services of $880,000, this would
result in a new HDR contract value of$3,470,000, as shown in the table below.
Services Fees Board Approval
Original Agreement with HDR for Steam Project December 20, 2018
Current HDR Agreement $2,590,000
Proposed Amendment— Electric Blower Pending
Improvements Final Design and Bidding $880,000
Services
Total Contract Value with Amendment $3,470,000 Pending
There are adequate funds within the current budget of the Steam Project, DP 7349 for the phasing
approach including Phase 1 (Electric Blower Improvements Project), the final design services with HDR,
and staff costs.
The total estimated project costs for the Electric Blower Project is $12.5 million. The anticipated cash flow
and project budget is as shown below:
Electric Blower Improvements Budget
Phase Budget- FY 2020-21 FY 2021-22 Future FYs Total
to-Date
Planning $0 $0 $0 $0 $0
Design 0 1,250,000 0 0 1,250,000
Construction 0 500,000 4,150,000 6,600,000 11,250,000
FY Total 1 $0 $1,750,000 F $4,150,000 $6,600,000 $12,500,000
The funding for the Electric Blower Improvements will be from the Steam Project, which will lower the total
estimated project budget as described below:
July 16, 2020 Regular Board Meeting Agenda Packet- Page 356 of 393
Page 6 of 17
Steam Project Budget
Phase Budget-to- FY 2020-21 FY 2021-22 Future FYs Total
Date
Planning $2,500,000 $0 $0 $0 $2,500,000
Design $1,750,000 1,250,000 350,000 2,250,000 5,600,000
Construction $750,000 0 0 42,150,000 42,900,000
FY Total $5,000,000 $1,250,000 $350,000 1 $44,400,000 $51,000,000
The current bid environment has been very favorable to obtain lower project costs. Based on the past six
(6) project bid openings, Central San has saved approximately$5.5 million compared to the engineer's
estimate and project budgets. These projects include the Influent Pump Electrical Improvements;
Lafayette Sewer Renovations, Phase 14; Walnut Creek Sewer Renovations, Phase 14; Lower Orinda
Pump Station ASD Replacements; Plant Control System 1/0 Replacement Project- Phase 2 Secondary
Process; and the Martinez Sewer Renovations, Phase 6.
COMMITTEE RECOMMENDATION
The Engineering and Operations Committee reviewed this item at the July 7, 2020, meeting and
recommended that the subject be presented to the full Board for discussion. No other recommendation
was provided. Staff has incorporated feedback from this meeting and refined the position paper as it
relates to the need for the project, BCEs, and project budgets.
RECOMMENDED BOARD ACTION
Staff recommends the following:
1. Approve the Electric Blower Improvements Project- Phase 1 in the Fiscal Year 2020-21 Budget
and funding from the Steam and Aeration Blower Systems Renovations, District Project 7349; and
2. Authorize the General Manager to amend an existing professional engineering services agreement
with HDR, I nc. to include final design for the Electric Blower I mprovements Project- Phase 1 for an
amount of $880,000, raising the agreement cost ceiling to $3,470,000.
Strategic Plan Tie-In
GOAL TWO: Environmental Stewardship
Strategy 1—Achieve 100% compliance in all regulations, Strategy 2—Anticipate and prepare for potential regulatory
changes
GOAL THREE: Fiscal Responsibility
Strategy 1—Maintain financial stability and sustainability
GOAL FIVE:Infrastructure Reliability
Strategy 1—Manage assets optimally to prolong their useful life, Strategy 2—Execute long-term capital renewal and
replacement program, Strategy 3—Protect personnel and assets from threats and emergencies
GOAL SIX. Innovation and Optimization
Strategy 1—Implement the Central San Smart Initiative, Strategy 2—Improve and modernize operations through
technology and efficiency measures
July 16, 2020 Regular Board Meeting Agenda Packet- Page 357 of 393
Page 7 of 17
ATTACHMENTS:
1. Presentation
July 16, 2020 Regular Board Meeting Agenda Packet- Page 358 of 393
Item 12. (Handout)
(Updated Presentation)
r
1
ELECTRIC BLOWER IMPROVEMENTS PROJECT
Jean-Marc Petit, Director of Engineering and Technical Services
Edgar J. Lopez, Capital Projects Division Manager
- '' Nitin Goel, Senior Engineer, Special Projects and Asset Management
Board Meeting
July 16, 2020 Updated
arA^1.9 1
DRIVERS FOR ELECTRIC BLOWER IMPROVEMENTS
Provide reliable aeration air during steam or power
outages at the treatment plant, especially for PG&E long
outages.
Allows prolonged shut down of the furnaces and
associated waste heat boilers during the Solids Handling
Facilities Improvement Project (Solids Project)
construction.
Addition of Electric Blowers lead to no stranded asset.
Improved Electric Blowers is recommended under all
future alternatives (short- and long-terms) for reliable
redundancy.
CFNTPAISAN
1
i
tmrU
{ 'DRAFT Secondary Process
•.: . ; and Aeration System 6lvConditionAssessment DRAFT Steam System
_ y
"` Condition Assessment
I,I5ream and RetaliBlow5yslem :.�- �-
Renovation PFuiect.DP 7349
si r: : l-N „:, _ Steam and Aeration Blower System
t ex Renovation Proiect.DP 7349
r
CONDITION AsSESSIVIENTS
r li
CONDUCTED • DATE
F Electrical Condition
Assessment
�.RxW Steam and A08110 Blower System
"^ Renoraliun Njecl.OP 7349
1011
AERATION BLOWERS ARE OPERATED USING STEAM SYSTEM WHICH
IS VERY COMPLEX AND EXTENSIVE
Sub 33
Sub
Sub 34
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2
ACTIVATED SLUDGE AERATION SYSTEM
• The heart of the liquid treatment is the secondary activated sludge process which
requires oxygen for the biological treatment. Oxygen is provided by aeration blowers.
SECONDARY PROCESS SYSTEM Air for
Biological
Treatment
Air used for
• mixing for
_ Channel Aeration
- (Final Effluent
and Mixed
Liquor)and Pre-
Aeration
_ 23. � •
111141
CENTPAL SAN
EXISTING AERATION
BLOWERS y
Manor Components
• Steam and Electrical Two Steam
Blowers/Aeration System Driven
• Steam Turbines Mounts Blowers
• Valves Casing
• Controls Shell
• Nozzle Blocks Lubrication
• Bearings
Vulnerabilities/Concerns y
• Complexity of steam system
• Inability to operate blowers in One Electric
parallel Driven
• Limited turndown capability Blower
• Lack of redundancy during steam
supply shortage
• Electric blower limited air capacity
and no redundancy ]
3
STEAM SYSTEM IS THE "ENGINE" THAT DRIVES
THE MAIN BLOWERS 1 AND 2
• Steam assets in need of more immediate attention (approximately five years or
more) include steam-driven blowers (turbines and exhaust condensers) and
waste steam exchangers.
Solids .
Scum Centrifuge
System Hot Wader
Heaber Exchanger
� I
sampling Systart copolymer:
Pumpingand Blower
• •
6oilerfeedwater and Ito goilers)�
___ condenser Ele<•trie Blower
6loadown sampling � I Feed Cooling Wale Bloxre Beat geservoir
rmca m pumps Steam r Eahangtt
Potable Cnndt oeaeratar i sCB Turbi
Makeup Water Storage Tank Oxygery HVAC gecycl� CW Re[um not W�
LW rite Steam
A g __ oged stag _
Turbi Euhangees W
Rmbie� CW Refur rgetum
NaZ Softeners A
E eclric, `i+5III
rani cu ngger, er ion F
East&�p — - o-. L
Xq Tunnelsm
OAreas of Concerns Requiring More
Immediate Attentions
CENTPAL SAN
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FURNACE BASE ISOLATION COORDINATION WITH THE SOLIDS
�IyI
DISTRICT PROJECT (DP) 7348
NEEDS
' 8
4
PARTIAL SHUT DOWN OF SOLIDS CONDITIONING BUILDING RECOMMENDED
DURING THE CONSTRUCTION OF THE SOLIDS PROJECT
0 ter• 1
V
s
, r
During construction of the Solids Project,furnaces,wet scrubbers, ash
loading, as well as waste heater boilers will likely be shut down for prolonged
time periods.
1 9
PARTIAL SHUT DOWN OF STEAM AND AERATION SYSTEMS
Solids ". • C
Expected to be out of service
• • •
sm,m CetWatee
System Hot 4YatExpected to remain in service
r
y,; W. Heater Exchanger
EmirP
� 1
Sa5ystem:
---- s Copolymer. Pumping • Blower Building(P&B)
g b�nerreea��aterad Ir'�I IroaaHers)- CoI—
P� gle�tar Add electric
blowdo do =tmpling tc Q.1 Feeds tems� CoolinHI nblowers
Potable CondtRe 111 Hot Wat 9 WtHeatersMakeupWater StorageTank oq ,o HVAC cur netum trop
$ A B -ng-. _ Waste Steam
Frrtiangers
anin� cw Return
He urn
az5oReneis A
E ectrk, "I"±' u er on
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a
Main steam producers:Multiple Hearth Furnace(MHFs)Boiler,Cogen Main steam consumers:Aeration Blowers
Boiler,Auxiliary Boilers(as needed) will not have sufficient steam supply during
Main Landfill Gas(LFG)user:MHFs.LFG user 4 Auxiliary Boilers peak demand.Add electric blowers to
during MHF shut down supplement air production
Main Natural Gas(NG)users:Cogen and Auxiliary Boilers(as needed) 10
CFNTPAI SAN
5
CENTRAL SAN WILL NEED TO RELY ON BOTH STEAM AND ELECTRICAL GRID
POWER DURING CONSTRUCTION OF THE SOLIDS PROJECT FOR AIR SUPPLY
TO SECONDARY PROCESS
kll�! YA
"E� 140
R
Steam
M
Electricity
Average electrical demand of new
*Existing electric blower cannot be run on standby power.New electric blowers will be powered using electric blowers is 1 to 1.2 MW
existing Electric Standby Generator,would supply power under Public Safety Power Shutoff event,if
sufficient steam is not available 11
CENTPAL SAN
LONG-TERM ALTERNATIVE # 1
STEAM AND ELECTRIC BLOWERS
• This long-term alternative would largely maintain status quo and renovate and
replace parts of existing steam system, steam turbines and adding new electric
blowers for added reliability
Solids / 1 1Buildingr n]
.•,, PPPiiiPPPiii {
Sam Ceiifuge 1 +e
system HotWeter �}
Heager Fichanger
Sampli°,yyy�„- C°polrmerf
Pumping I Blower 1• -
ballefe�vXerand (1� Itoeoilerq� Goodman EI.—
hl°wd°wn s.mping aIkMS a Cooling Wattt Blourer E• ryeat Peurvoir ��V/\j
an P""pa _��JLr1fl Exebanger
potable C°nM pexralor '
Makeupw r smrsgerank °; HVAC IeW` cwwtum H°g wart,Heaters
A 8 -reed i w�asreaa� �'
Ftthangers �
Nnm�' (W PeWm i�PNutn
E.,
Edit&i® 1�{a+ tu.
I �
*New electric blowers can be powered 1
Renovate Replace1 using existing Electric Standby
Generator,would supply power under
Existing Steam System Public Safety Power Shutoff event,if
sufficient steam is not available 12
6
LONG-TERM ALTERNATIVE # 2
ALL ELECTRIC BLOWERS WITH STEAM TURBINE ELECTRIC GENERATOR
One other long-term alternative that faired better than others is adding new
electric blowers & generate power with a new steam turbine generator
CAW-
Furnace
L
H at Bo
e Hers
All New Blowers with VFDs-Example
Auxiliary Boilers Magnetic Bearing Electric Blower from
SCe
District
dui 000 11s,per 15 MW of power produced can
IF lbs.per hour by hour can produce ower reater than meet average aeration air
��� ��� steam of
demands
three boilers *New electric blowers can be powered using existing Electric Standby Generator,would supply power
under Public Safety Power Shutoff event if sufficient steam is not available
CENTRALSAN
STEAM PROJECT PHASING
Phase 1: Electric Blower Improvements - Refurbish and add New
Electric Blowers in Pump & Blower Building and for Pre-aeration tanks.
Phase 2: Complete the Evaluation of Steam System and Determine
Upgrade of Existing Steam System vs. Conversion to Electric with Steam
Turbine Power Generator.
Phase 3: Secondary Process Improvements including Aeration Tanks, Mixed
liquor division box, Secondary Clarifiers, and associated Electrical and
Controls Systems. Included in Ten-Year CIP
Phase 4: Rehabilitation of other elements that could be impacted if/when a
Water Exchange Project was to proceed.
Phase 5- Modifications and additions for Future Nutrient Removal.
CFNTPAISAN
' 14
7
FOCUS AREA FOR ELECTRIC BLOWER IMPROVEMENTS
• Electric Blower
Improvements Project will
-' also focus on Electrical Sub
a =.Rp /N Tanks Aeration Station 52.
Aeration Blowers sUb s2
Project will replace/improve
electric and controls
i r`'' -- equipment identified for
R = immediate attention and will
consider replacing or adding
new feeders and/or motor
starters to keep these
..� f
lifespans insync with new
.,
x _,:,. . f-•��� + asset life (Electric Blowers).
•II[LEGIGEIIEI[[}j Pre-Air Tanks Aeration
lllllllllll!![!L .
lltllllllllll9!€�I '
IDDI➢tDgllCttf��
-s -
CENTRALSAN
ELECTRIC BLOWER IMPROVEMENTS
TOTAL ESTIMATED PROJECT COST
FY 20-21, FY 21-22,AND FY 22-23
ComponentsProject
$9.2 M
Total Estimated Project Cost $12.5 M
• : $0.5 - 1.3M
1.Furnaces are considered to be non-operational for 1 year,therefore,Central San would
be relying on both reduced steam from Auxiliary and Cogen Boilers and PG&E for
electricity for 1 year.Range of annual cost depending on demand.
Funding from the Steam and Aeration Blower Systems Renovations,DP 7349 has a total project budget of$63 million(M)in
Fiscal Year(FY)2020-21 Budget. j
AN 1
8
PROJECT FUNDING Updated Slide
• The total estimated project costs for the Electric Blower Improvements is$12.5 million.
• Staff plans to pre-select the critical and long-lead items,such as the electric blowers and electrical gear
for this project.The proposed cash flow below represents the standard time expected for equipment
procurement of this size and is subject to change depending on the equipment manufacturer selected
and actual installation timing.The anticipated cashflow and project budget is as shown below.
• The funding for the Electric Blower Improvements will be from the Steam Project,which will lower the
total estimated project budget from$63.5 million to$51 million as detailed below:
Steam Project Budget
® Budget-to- 11111Date FY 2020-21 FY 2021-22 Future FYs Total
$2,500,000 $0 $0 $0 $2,500,000
$1,750,000 $1,250,000 $350,000 $2,250,000 $5,600,000
$750,000 $0 $0 $42,150,000 $42,900,000
$5,000,000 $1,250,000 $350,000 $44,400,000 $51,000,000
Electric Blo.er lmpro�ements Project Budget
® Budget-to- FY 2020-21 FY 2021.22 Future FYs Total
Date
$0 $0 $0 $0 $0
$0 $1,250,000 $0 $0 $1,250,000
$0 $500,000 $4,150,000 $6,600,000 $11,250,000
$0 $1,750,000 $4,150,000 $6,600,000 $12,500,000
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AGGRESSIVE SCHEDULE FOR Updated Slide
ELECTRIC BLOWER IMPROVEMENTS
Estimated time when
the Solids Project will
impact the
Year 2020 Year 2021-2023 incinerators and
waste heat systems is
Fall 2022.
July 16 Aug 31 Oct 30 Feb May-June August Oct 31
2020 2020 2020 2021 2021 2021-Sept 2022
2022
Board 10%Design Equipment Submittal
Bid/Award Construction Completion
Approval Submittal Procurement
Documents&
30%
Submittal I18
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BOARD ALTERNATIVES Updated Slide
The Board could consider several alternatives for the Electric Blower Improvements, as follows:
Alternative 1: Status Quo-Do Nothing Alternative,which would continue to leave the
treatment plant's backup power systems vulnerable to long PG&E power outages.This
would also impact the Solids Project by limiting the furnace shut down options and
increasing construction risk associated with the steam and waste heat systems.
Alternative 2: Include or combine the Phase 1 Blower Project with the Solids Project. Staff
has considered this alternative, but the Solids Project is expected to bid later this calendar
year.This alternative could delay bidding of the Solids Project into 2021.
Alternative 3: Install temporary blower or backup power systems to achieve the air demand
needed for the Steam and Solids Projects or under long PG&E power outages,which adds
significant costs.
These alternatives are not recommended by staff.
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RECOMMENDED BOARD ACTION
• Approve the Electric Blower Improvements Project in the Fiscal
Year 2020-21 Budget and funding from the Steam and Aeration
Blower Systems Renovations, District Project 7349; and
• Authorize the General Manager to amend an existing
professional engineering services agreement with HDR, Inc. to
include final design services in an amount not to exceed
$880,000, raising the agreement cost ceiling to $3,470,000.
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QUESTIONS?
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