HomeMy WebLinkAbout04.b. Review draft Position Paper to approve the Electric Blower Improvements - Phase 1 Project in the Fiscal Year 2020-21 Budget and funding from the Steam and Aeration Blower Systems Renovations, District Project 7349; and amend an existing professiona Page 1 of 20
Item 4.b.
CENTRAL SAN BOARD OF DIRECTORS
POSITION PAPER
DRAFT
MEETING DATE: JULY 7, 2020
SUBJECT: REVIEW DRAFT POSITION PAPER TOAPPROVE THE ELECTRIC
BLOWER IMPROVEMENTS - PHASE 1 PROJECT 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, I NC. I N 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
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 the
condition assessment and preliminary design of the Steam and Aeration Blower Systems Renovations,
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 the final design of Phase 1 - Electric Blower
Improvements (Phase 1 Blower Project).
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 19 of 49
Page 2 of 20
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 plant's 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, shut downs, 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 back-up when the steam system is shut down for
maintenance or under emergency scenarios. However, there are several shortcomings associated with that
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). That 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 treatment plant would have insufficient process air
and steam production during the construction of the Solids Handling Facilities Improvement 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
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 treatment plant and especially
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 20 of 49
Page 3 of 20
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 the
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&GE, 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 Solids Project 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 has long-term benefits.Apart from the capacity
deficiency to meet the peak aeration demands under steam power, 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).
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 and Clearwell Improvement 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
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 21 of 49
Page 4 of 20
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 & 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 of the
existing steam system vs. 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.
Electric Blower Improvements - Phase 1 Blower Project Approach
Staff is recommendeding to proceed with the design of Phase 1 at this time. Phase 1 Blower Project
includes the following main elements:
• Refurbish and add new electric blowers in the Pump & 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 (after completion of construction of the Solids Project) of the
Phase 1 Blower Project is decribed below:
• Recommended under both long-term alternatives;
• 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 treatment
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.
ALTERNATIVES/CONSIDERATIONS
The Board could consider several alternatives for 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.
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 22 of 49
Page 5 of 20
FINANCIAL IMPACTS
The total anticipated cost for the final design of the Phase 1 Blower Project 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 an additional $880,000 for Phase 1 Blower Project, 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— Phase 1 Final Design Pending
and Bidding Services $880,000
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 the Electric Blower Improvements Project— Phase 1, the final design services with
HDR, and staff costs.
COMMITTEE RECOMMENDATION
The Engineering and Operations Committee reviewed this item at the July 7, 2020, meeting and
recommended
RECOMMENDED BOARD ACTION
Staff recommends the following:
1. Approve the Electric Blower Improvements - Phase 1 Project 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 - Phase 1 Project for an
amount of $880,000, raising the agreement cost ceiling to $3,470,000.
Strategic Plan re-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 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 23 of 49
Page 6 of 20
ATTACHMENTS:
1. Presentation
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 24 of 49
Page 7 of 20
STEAM AND AERATION BLOWER SYSTEMS
RENOVATIONS, DISTRICT PROJECT 7349
STATUS UPDATE AND PHASED APPROACH
Jean-Marc Petit, Director of Engineering and Technical Services
r-, Edgar Lopez, Capital Projects Division Manager
_ r Nitin Goel, Senior Engineer, Special Projects and Asset Management
Engineering and Operations Committee Meeting
July 7, 2020
DRIVERS FOR PHASE 1 BLOWER PROJECT
Provide reliable aeration air during steam production
outage under standard operation.
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.
3
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 25 of 49 1
Page 8 of 20
WHY BLOWER PHASE 1 NOW:
1 . CONDITION AND CAPACITY
ASSESSMENT IDENTIFIED
VULNERABILITIES
Recommended Action: Provide reliable aeration air during steam
production outage under standard and emergency operation by
adding electric blowers.
l' t DRAFT Secondary Process
_ and Aeration System DRAFT Steam System
Condition Assessment i
Steam and Aeration Blower System -'t L®1L.�Pp�I Condition Assessment
w _ Renovation Project,DP 7349 �ieL ��I ■u Y
FJ� J.,-14.2020 W,[� ■_,, Steam and Aeration Blower System
Renovation Proiect.DP 7349
cmilm
CONDITION
CONDUCTED • DATE
Electrical Condition
Assessment
Steam and Aeration Blower System
Renovation Project,DP 7349
fZ� No, d,n—y14,2020
4
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 26 of 49 2
Page 9 of 20
STEAM SYSTEM IS VERY COMPLEX AND EXTENSIVE
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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.
ECONDARY PROCESS SYSTEM Air for
Biological
Treatment
Air for Channel
Aeration(Final
Effluent and
Mixed Liquor)
and Pre-Aeration
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July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 27 of 49 3
Page 10 of 20
AERATION BLOWERS 91
Manor Components
• Steam and Electrical Two Steam
Blowers/Aeration System Driven
• Valves Mounts Blowers
• Controls Casing
• Nozzle Blocks Shell
• Bearings Lubrication
Vulnerabilities/Concerns
�i
• Complexity of steam system
• Inability to operate blowers in
parallel One Electric
• Limited turndown capability Driven
• Lack of redundancy during steam Blower
aA
supply shortage
• Electric blower limited air capacity t a
and no redundancy
t 1
STEAM SYSTEM IS THE "ENGINE" THAT DRIVES THE BLOWERS
• 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 Conditioningi i
scum Centrifuge
System HotWater
Heater Exchanger
i I
Sampling System: •Copalymer•m Pumping Blower • •
bciler feedvater and
oto eollers)
Condenser Hertdc Blower 3
blcwdov:n sampling C mical Feed Systems fooling Water Blower Heat Reserwir
Pumps Steam 10
_ Exch
Potahle fondt peaerater SCB Turbi anger
Makeup Water Storage Tank Recycle Hot Wat H7,
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g oxygen HVAC cw Retum too
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s` "" Turbi Exha
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Eleclrrc, ;"'y!i.- -:_,-.:''l cu ogger� er ion
EEase&is _ E
Tunnels rates endenaeReum
OAreas of Concerns Requiring More '
Immediate Attentions
CENTPALSAN
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 28 of 49 4
Page 11 of 20
WHY BLOWER PHASE 1 NOW:
2. CENTRAL SAN IS NEARING DESIGN
COMPLETION FOR
THE SOLIDS PROJECT
Recommended Action: Adding Electric Blowers allows prolonged shut
down of the furnaces and associated waste heat boilers during the
Solids Project construction.
it
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v oil
10
liu �I11 i'
II II �
FURNACE BASE ISOLATION
COORDINATION WITH SOLIDS
PROJECT DP 7348 NEEDS
' 10
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 29 of 49 5
Page 12 of 20
PARTIAL SHUT DOWN OF SOLIDS CONDITIONING BUILDING RECOMMENDED
DURING THE CONSTRUCTION OF THE SOLIDS PROJECT
r
i
I
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.
CFNTPAL SAN
PARTIAL SHUT DOWN OF STEAM AND AERATION SYSTEMS
Expected to be out of service
Solids • • • •
I Sam H WI Expected to remain in service
' H� ErrJianger
ii Sampling System. Copolymer ,umping and Blower ,
6oilerfeedwaferand (,�` �togolers� Condenser Elecidc Building Add electric
6lowdown sampling mical Feeds'terns' Cooling Water ql Heat geservoir
Pumps S Eachanger blowers
Potable Condt peaera[or SIB gecycle Hot Water�j 'firWater Heaters g
Makeup Water Storage Fank pnygenHVAC [W LW getum� W.P u
S A g srarenge� I wade steam F
g � ____ puhangers CW
_V__A_m_i n_eyClY getu rn ��geturn
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Electric, ,j::,_zea; ji',,ii cu ogger, er on p
EEast&
� " )l_h,� n sem ndensate Return B
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) 11
CFNTPALSAN
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 30 of 49 6
Page 13 of 20
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
Steam
Electricity
Average electrical demand of new
Electric blowers can be powered using existing Electric Standby Generator,would supply electric blowers is 1 to 1.2 MW
power under Public Safety Power Shutoff event,if sufficient steam is not available '
CFNTPAL SAN
WHY BLOWER PHASE 1 NOW:
3. IDENTIFYING LONG-TERM ALTERNATIVES
FOR BLOWERS
Recommended Action: Note that Addition of Electric Blowers is
recommended under all alternatives (short- and long-terms) for
reliable redundancy and will not be a stranded asset.
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 31 of 49 7
Page 14 of 20
AERATION IS REQUIRED ON CONTINUOUS BASIS — CURRENT PLAN
1. Air Demand: Current Range 38,000 to 73,000 standard cubic feet
per minute (scfm)
2. Steam Blower is primary source of air, back-up is second Steam
Blower, 71,000 scfm each
3. In case of steam shortage or outage, we rely on a single electric
blower which has only 30,000 scfm capacity
4. Blowers cannot run concurrently in parallel, only one at a time
5. Unknown reliability with existing power standby: Existing standby
diesel generators have limitation on supplying power to existing
standby blower (2,000 Horsepower synchronous motor— No
Variable Frequency Drive (VFD), No soft starter). Not reliable
under PG&E Public Safety Power Shutoff
15
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
Solids1 • Building(SCB)
..
Scum
System HM.Vk..ter 1
Healer E hangar
Sampling SyAem: r Coplymer'
Pumping r Blower r ,
boperleeAe rera�d fj Iroeoilersl Building
'r
I'I sae B tlno
blzwe wn sampling themip Feeds rem! Cooling WMtt glov ryeatpeservoir
PumPa Excbanper
Pornele cm,dr oeaemfor SLB
MakeuPWarer Nomgeiank aemxley Ibr Vlar j—+Water Hearers
mygeo HVAL gu, cwnAum Eoop
A 8 s�reer IITw esream
Exdaneem nv
Pmine CW aeNm rgNum
flMriS 'yF uum,ogger, er on Y
EaA&[7 rt tij-��14r &
*New electric blowers can be powered
Renovate • Replaceof using existing Electric Standby
Generator,would supply power under • ,
Existing Steam System Public Safety Power Shutoff event,if
sufficient steam is not available ,• ' 16
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 32 of 49 8
Page 15 of 20
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
llllll�
+ n 9F
BlowersFurnace Waste
Heat Boilers
All New
BoilersAuxiliary
SCB
steam of dui to 38,000 power produced
hour can produce power greater than meet average aeration air
1.5 MW
•• * demands
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 17
CFNTPAL SAN
UPDATED PLAN WITH BLOWER PHASE 1
1 . Air Demand: Current Range 38,000 to 73,000 scfm
2. Steam Blower is primary source of air, back-up is second
Steam Blower, 71 ,000 scfm each
3. In case of steam shortage or outage, ADD two new
electric blower with VFDs which have 35,000 - 40,000
scfm capacity each
4. New Electric Blowers will be able to run concurrently in
parallel
5. Existing standby diesel generators will be able to power
, new blowers under a PG&E Public Safety Power Shutoff
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 33 of 49 9
Page 16 of 20
STEAM PROJECT PHASED APPROACH
AND
DEVELOPMENT OF THE ELECTRIC
BLOWER IMPROVEMENTS —
PHASE 1 PROJECT
CFNTPAL SANI
STEAM PROJECT PHASING
Phase 1: 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 CI
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.
I za
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 34 of 49 10
Page 17 of 20
FOCUS AREA FOR PHASE 1
• Blower Phase 1 will also
focus on Electrical Sub
Station 52.
■��`Oi ti "�'' A/N Tanks Aeration
Project will replace/improve
Aeration Blowers subsz ■J� ®�®
=_ electric and controls
r— � 1 equipment identified for
immediate attention and will
• — Buried Butterfly Isolation Valves consider replacing or adding
Ilknew feeders and/or motor
�tJra j � starters to keep these
lifespans in sync with new
_ asset life (Electric Blowers).
sllllllllllll IIII IY
ll101111111101 Pre Air Tanks Aeration
1111111111111111 I� �;�r���'%
CFNTPAL SAN
:111111111111011 }
PRELIMINARY SCOPE OF ELECTRIC BLOWER
IMPROVEMENTS - PHASE 1
• Refurbish and add Electric Blower(s) in Pump &
Blower Building for Aeration Redundancy
• Add Dedicated Small Blowers for Pre-Aeration,
and Channel Air (Mixed Liquor and Final
Effluent)
• Add associated electrical instrumentation and
controls systems improvements to support
process renovations
CFNTPAI SAN
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 35 of 49 11
Page 18 of 20
ELECTRIC BLOWER IMPROVEMENTS - PHASE 1
TOTAL ESTIMATED PROJECT COST
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 one year.Range of annual cost depending on demand. 10000ma—
District Project 7349 Steam and Aeration Blower Systems Renovations has a total project budget of$63 million(M)in Fiscal Year 2020-21 Budget
' 23
CFNTPAL SAN
AGGRESSIVE SCHEDULE FOR
ELECTRIC BLOWER IMPROVEMENTS - PHASE 1
Estimated Time when
the Project
Year 2020 Year 2021-2023 shut dolwnds furnaces`II
Fall 2022.
(August2021
July 16 Aug 31 2020 2021 2021 Oct 30 Feb ay-Jun July-Jul 31,
2022
2020 2020 2022
•
Board 10% Design Equipment Submittal
Bid/Award Construction Completion
Approval Submittal Procurement
Documents&
30%
Submittal
CFNTPAL SAN
July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 36 of 49 12
Page 19 of 20
ALTERNATIVES/CONSIDERATIONS
ZVI-
-E
CFNTPAL SAN
PHASE 1 ALTERNATIVES/CONSIDERATIONS
The Board could consider several alternatives 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: 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 systems to achieve the air demand
needed for the Steam and Solids Project, which adds significant costs.
These alternatives are not recommended.
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July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 37 of 49 13
Page 20 of 20
RECOMMENDED BOARD ACTION
• Approve the Electric Blower Improvements - Phase 1 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.
CFNTPAL SANI
QUESTIONS?
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July 7, 2020 EOPS Regular Committee Meeting Agenda Packet- Page 38 of 49 14