HomeMy WebLinkAbout08.a. Attachment 2 - CWMP Technical Executive Summary ATTACHMENT 2
- Central Contra Costa Sanitary District
- "Central San"
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Tec h n 'ica I Executive Summa
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in association with
WOODARD
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Comprehensive Wastewater Master Plan
%,AL I XL*,',tj TIVE SUMMARY
1. EMBARKING ON A COMPREHENSIVE
WASTEWATER MASTER PLAN
Mission
Central San's core mission is to protect public health and the environment by
reliably collecting and treating wastewater from over 480,000 residents and
approximately 3,000 businesses it serves. In addition to collecting and treating
wastewater,Central San provides recycled water for parks,medians,school
fields,and golf courses and manages both commercial and residential recycled
water pick-up programs.Central San also operates a household hazardous waste
collection facility and a sophisticated water quality laboratory.
Central San's service area is complex and widespread. It covers 147 square miles
in central Contra Costa County and spans a variety of microclimates and terrain.
Central San's treatment plant,located at the intersection of Interstate 680 and
State Route 4 in Martinez, processes about 32 million gallons of wastewater per
day and has managed peak flows as high as 230 million gallons per day during
an extreme winter storm.Central San has successfully
'" �UAsune managed and treated flows, maintaining 100 percent
effluent permit compliance for the last 18+consecutive
---` years.
.'[.Mar"#inez -- Central San uses over 1 500 miles of piping with over
�- � p�p� 9
35,000 manholes and 19 pump stations to convey
Concord wastewater to the treatment plant in Martinez.
Pleasant
Hlil The average age of the collection system pipes is
approximately 40 years.Some pipe segments are over
Orin WalnutClayton 100 years old,and some of the most critical pump
Creek
ye#te stations are over 55 years old.
Since its original construction in 1948,the treatment
plant has been modified through successive projects,
Morava including a major expansion to secondary treatment
in the 1970s.Although other improvements have been
made since then, most of the treatment plant remains
unchanged.
DanVille
CCCSD Sphere of Influence Together,the collection system and treatment plant
Major Highways
Major Roadways have an estimated replacement value of over$4 billion.
p Clayton 'san" Despite their age,both are generally in good condition.
Concord Ramon,
City Boundaries However,repairs and upgrades are required to maintain
CCCSD Service Area reliable operation and protect Central San's assets.
Waterbodies
Central Contra Costa Sanitary District Service Area
Challenges and Opportunities
In the future,increasing regulatory requirements may require Central San to Planning Objectives
upgrade its treatment plant. In addition,potentially more extreme flows during Preserve,maintain,or replace
high and sustained storm events,enhanced by climate change, may test the assets for the collection system
capacities of the collection system and the treatment plant.Along with potentially and treatment plant.
more restrictive regulations,aging infrastructure,and capacity challenges, Meet increasingly stringent
several opportunities are available to reduce costs through improved efficiencies, g y g
pp g p regulatory requirements
resource recovery such as recycled water and energy recovery,and renewable for treated effluent,solids
energy production.
management,and air emissions.
Central San manages a significant amount of infrastructure with thousands of Accommodate planned growth in
mechanical and electrical equipment,structures, instruments,and other assets. the service area.
Most of its 4,000+assets were constructed in the 1970s and funded by federal
Achieve sustainability goals by
grants offered after the passing of the EPA Clean Water Act that required facilities
optimizing energy recovery and
to provide secondary treatment.
consumption while minimizing
Although Central San's robust maintenance practices have extended the lives greenhouse gas emissions.
of many assets,eventual rehabilitation or replacement is needed. Nevertheless, Increase recycled water
replacing them is a significant undertaking that will incur significant cost and production for new customers,
investment from ratepayers since the federal grants offered in the 1970s are such as the Concord Community
no longer available. Recognizing the importance of protecting its assets,public Reuse Project Development.
health,and the environment,Central San commissioned the Comprehensive Explore new wholesale recycled
Wastewater Master Plan(CWMP)to build on previous planning efforts. Planning water opportunities and evaluate
objectives include the following: alternatives to supply recycled
water for the neighboring
refineries.
POLICY ;
Maximize
--------------------
Existing Spin Out
ASSESS Infrastructures ; Immediate
• • .•••••,• •
_________
1. Condition '' '
__________ _ Projects
2. Capacity '
•
3. Reliability
IDENTIFY i 's
GAPS/ PRIORITIZE Long Term
OPTIONS CIP
STRATEGIZE
1. Regulations
2. Risks '
i
3. Needs Refine
4. Opportunities POLICY
's Innovation/
Leadership
Master Planning Process
2 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
The CWMP's primary objective Sustainability/Optimization
is to develop a structured plan By using sustainable practices,Central San can minimize operating and
that addresses these objectives maintenance costs and increase the facilities'resiliency to withstand
and provides a basis for orderly natural disasters. Projects in this category include optimizing the
expenditures as other needs develop. existing treatment processes,energy efficiency improvements,reliability
Because Central San already improvements,improvements to bolster resiliency against manmade or
completed extensive analyses, natural disasters,and increasing recycled water production.
condition assessments,and inspections
for the collection system and For recycled water,recent drought conditions might persist,meaning
treatment facilities,their efforts were water purveyors need a sustainable,alternative water supply in the near
the CWMP's foundation. future. By providing high-quality recycled water,combined with other
effluent management approaches,the District may be able to achieve a
Recommendations from the long-term goal of zero discharge.
CWMP are incorporated into a
capital improvement plan(CIP), Regulatory
which provides a prioritized list of The District must comply with many permits and policies that govern
future improvements and ongoing the operation of its facilities. In the coming years, regulations for air and
renovations and is the basis for the effluent discharges will likely be more restrictive.Stricter nutrient limits for
capital improvement budget(CIB). effluent discharges to Suisun Bay are expected to trigger the need for new
treatment processes.Changing regulations for air quality and greenhouse
Early in the project,the CWMP team as emissions may create the need for new energytechnologies. In
identified the followingfour keyg y g
addition,some improvements will be required to comply with current
"drivers,"'which are issues and goals ermitre requirements severe wet weather conditions.
provide rovide direction for the CWMP: p q g
�
Aging Infrastructure Capacity
Projects to expand capacity are needed to accommodate increased
The existing wastewater assets,such
as wastewater flows for the tannin period. Population growth within the
is
pipes,pumps,sp ,buildin g ,tanks, planning
p service area will increase wastewater flows and loadings,which may
and process equipment,will continue
to deteriorate with ag trigger the need for expansions of treatment processes and collection
e.Some will
reach the end of their useful life within system infrastructure.
the planning period.To maintain
its high standard of service,Central
San will prioritize repairing and
replacing critical assets.The repair
and replacement program will protect s
current investments in infrastructure
and extend its useful life.
�►L�IAN
14C
r
f
�r
Technician Welding- Ongoing maintenance has helped extend the life of
piping and equipment.
COMPREHENSIVE WASTEWATER MASTER PLAN 1 3
2. CENTRAL SAN AT
A GLANCE
1, F7irviewIMZ
Collection System
q
Central San's service area comprises _ �,.. v °nc°rd' uWa'
147 square miles that include the cities I�Ar
,';, arbrt�
of Danville Lafayette, Moraga,Orinda
Y
Bu�hanara No oath "
Pleasant Hill,Walnut Creek, portions of
Martinez and San Ramon,and several Cid
unincorporated communities in Alamo
Clayton
and Pacheco.
svii Roble
sleep;H�w�r ,,
The collection system has 1,500 miles _ nerRa -.
B a as gl d_
of gravity sewer pipes,over 22 miles A.c.Mm Lafayette".
°
-
of force mains,19 pumping stations, eek
and roughly 35,000 manholes.Central LowerON;d
San owns and operates the collection Flush Kleen
systems for Alamo, Blackhawk,Clyde, Orinda -
Danville Diablo Lafayette, Martinez,i Y i nezi O'�nda Crossroads
Moraga,Orinda, Pacheco, Pleasant 'Moraga �-�
HillHill Rossmoor,San Ramon and Walnut '�'°' � . r
, i i •fD�anvilfe:
Creek.
a
Central San alsorovides wastewater
p _
Pump Station
treatment for the Cit of Concord and
Y Farce Main
the Town of Clayton.The City of Concord Gravity Sewer
CCCSD Service Areae,
operates its own collection system,which Costa Conta County Parcels
also serves the Town of Clayton while
City Boundaries 0 Martinez Sa
fan Rarrron
Central San owns and manages a small 0 Clayton 0 Moraga °�R ' °'
......
portion of the collection system in north O Concord O Orinda
Danville 0 San Ramon
Concord. ,�Lafayette O'Vvafnut Creek
Central San works to ensure that Existing Collection System
wastewater is reliably collected and
conveyed to its treatment plant.To
reduce the chance of sewer system overflows(SSOs),Central
San cleans and inspects pipes throughout its service area and
works routinely on sewer renovation projects to rehabilitate or
replace pipes in poor condition.Throughout the year,Central
xJ
San crews clean over 800 miles ofi e and over 150 miles of
p p �
pipe is inspected using closed circuit television(CCTV)cameras.
This combined approach of robust maintenance and routine
p p 't
pipe renovation has maintained an SSO rate less than 3.0
per 100 miles(e.g.2.65 per 100 miles in 2016),less than both
national and California averages.
Central San Collection System Crew
41 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN MAY 2017
Treatment Plant Liquid Stream Processes
The treatment plant is a conventional The liquid stream processes include
air-activated sludge facility that influent bar screens,screenings
provides secondary treatment. Final removal influentpumping,aerated
treated effluent is disinfected and then grit removal,primary sedimentation,
conveyed by a 3.5-mile underground primary effluent pumping,secondary ■
outfall pipeline to the Suisun Bay treatment with a conventional
shoreline.At the shoreline,the pipeline activated sludge process with
transitions to a submerged outfall secondary clarifiers,and ultra violet
that extends 1,600 feet into the Bay. (UV)disinfection.A portion of the final
disinfected effluent is then further
Solids removed are dewateredand
then conveyed to one of two multiple treated to produce recycled water,
hearth furnaces.The furnaces reduce and the remaining flow is sent to
the solids to ash,which is beneficially Suisun Bay through g the outfall. Dry '1E
reused as a fertilizer amendment by weather season flows(when minimal
.r t�trttwr;�,��t•a-
a third party.Waste heat from the stormwater contributes to the flow) AIN
furnaces is recovered and converted currently average around 32 million Treatment Plant Operator
to steam energy used to drive aeration gallons per day(mgd). During the wet
blowers that supply air for the season,peak hourly flows can exceed
activated sludge biological process. 200 mgd.
Addressing
Limitations of Existing
Recycled Water System
.. ........................
.................................
Community
Impacts and Rates
.......... .............................
........................................... -- _ ......................................
Planning for Future
a. g Incinerator
Nutrient Removal
Emission Compliance._..
.............. ..........
...
Opportunities/
Costs for Future __ - ,:���► ►� ............................................ ........................................
Recycled Water, ' �� �° ' ►�� Future Ener
gy Changing Conditions
Including Zerol "����, ' °�►� � Regulations
Balance with
Discharge �� � ' `'� �► � . Reduced Landfill Gas . -'j' -Water Demands
,... .� _- ®r��► _ _ y _Climate Change
� � � ,�
....................................................
Optimization of ~� Hydraulic Capacity and
�,
Cost and ODM for f Reliability for Wet Weather
Disinfection al: .......... .............
................
....
........................................ !`vim Dry and Wet
Opportunities Flow Projections
for Innovation and r. :.
j.
Resource Recovery
Realistic Costs for Prioritized Rehab/
CIP Development Replacement
"' Schedule to Address Reliability of
Aging Infrastructure Pump Stations
.............................................: :..................................
Existing Treatment Facilities
COMPREHENSIVE WASTEWATER MASTER PLAN 5
Recycled Water
Around 550 million gallons per year of recycled water is produced for off-
site customers through the purple pipe recycled water distribution system,
and for residential and commercial recycled water pickup programs.Off-
site customers use recycled water for landscape irrigation at schools,parks,
businesses,golf courses, medians,and for commercial applications such as
truck washing,concrete manufacturing,dust control,and toilet flushing.
The recycled water process includes dual-media sand filters followed by
disinfection with sodium hypochlorite(bleach)to meet tertiary-treated Title
22 recycled water quality standards.The recycled water is then stored in a
reservoir prior to distribution(referred to as the Clearwell).Of the 550 millionf-
y.
gallons of water reused each year,around 1 mgd is used on-site for processes ~V.�
and landscape irrigation and over 0.5 m d is used by customers. a
�.
Solids Stream Processes and Energy System _•
The solids processing and energy systems consist of dissolved air flotation
thickeners to concentrate the waste activated sludge(WAS),centrifuges +�
to dewater a blend of primary sludge and thickened WAS,and multiple Recycled Water Pipes
hearth furnaces to incinerate the dewatered sludge,typically operated
using locally available landfill gas.Around 95 percent of the treatment plant
power demand is satisfied with a natural gas turbine cogeneration system.
The remaining power needs are supplied with electricity purchased from
PG&E.Waste heat recovered from the incinerator and cogeneration turbine
generates about 80 percent of the treatment plant's steam demand,of which
90 percent is needed to drive the aeration blowers.The remaining steam
demand is supplied by auxiliary boilers that can run on either natural gas or
landfill gas.
Wet Weather Wet Weather
Pumps Storage
Return
O to Plant
Primary
3/4"Bar Influent Aerated Primary Effluent Anaerobic Aeration Secondary Uv
Screens Pumps Grit Tanks Clarifiers Pumps Selector Tanks Clarifiers Disinfection
r.
—4n
—10T
O
I F o To
RAS O Suisun
Screenings Grit Bay
Dual Media
Filters
WAS To Disinfection
and Off-Site
Reuse
Backwash Sludge Storage
Bins
Centrate Lime
DAFTs Addition
Ash
Sludge Centrifuges
Blending MHFs
Treatment Plant Process Schematic Tank
6 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
3. PLANNING FOR COMMUNITY GROWTH
To evaluate Central San's capacity
to accommodate planned growth 600,000
over the next 20 years,Central San 575,000
and its consultants contacted the
cities,town,and County for the latest 550,000 9000'
General Plan and other development 525,000 �-
0
information. Population projections co 500,000
and corresponding projections 475 000
of wastewater flows and loads
(wastewater strength)were developed 450,000
and later compared to the treatment 425,000
plant's flow and load capacity. Future 400,000
flows and loads were estimated by 2010 2015 2020 2025 2030 2035
applying historical per-capita flows
Service Area Population Projections
and loads to the projected population.
Population projections were based on
the General Plans and development information,and the Association of Bay Area
Governments'(ABAG)population projections for communities in the service area.
For the most part,influent flows and loads have increased steadily since the
District's inception in 1946. However,in three periods,flows declined from
drought and economic conditions,such as during the late'70s and early,90s.
Starting in 2008,the District experienced an unprecedented long-term reduction
in dry weather flows that lasted through 2015.This reduction was caused by the
recession,a persistent drought,and water conservation measures. In 2016,the
flows rebounded slightly(from 29 mgd to 32 mgd)but not yet to the pre-drought
flows of around 35 mgd.
Historically,flows have returned to near pre-drought conditions when normal
rainfall patterns resumed and water usage increased after drought restrictions
are lifted. However,a full rebound may never occur this time,because water
conservation measures and investments from residences and businesses may
permanently reduce water consumption and wastewater flows.The CWMP
assumed flows would rebound to approximately 34 mgd and would steadily
increase at an average rate less of less than 1 percent per year for the next 20 years.
50 41
900
40 --"'
E 30
0
20
Q
10
—Historical ADWF Projected ADWF
0
1950 1960 1970 1980 1990 2000 2010 2020 2030
Historical Dry Weather Flows and Projection
COMPREHENSIVE WASTEWATER MASTER PLAN 7
4. EVALUATING INFRASTRUCTURE NEEDS
Collection System
Condition and Risk -
Assessment
Planning investments in the
collection system requires ti
knowing the condition of the
collection system assets and
leveragingn
data and asset
information to predict when Martinez
- -- �\
an asset will fail.The methods ;
used to assess the condition
Concord
and risk of the collection _ =t •,z:._�•
� /14 Clayton
system Y b assett e: y=� -��_=' •�
Y type:
• Gravit sewers Most of -=�•
y Lafayette
��,�--% 'rte�•� �1
the Central San collection '�� - j r' �. ,� -
.k� ill r �f .1ti/' � �' /� J
f ,_7
system consists of gravity �`���:'- .-� °��.�� �==� = -- �J �
0 S rr /
sewers.Gravity sewers •
_Z
were analyzed with a newly
Walnut Creek
implemented state-of-the Orinda ._, ',;�NS
art InfoMaster pipeline
degradation modelingVIA r
software,which helps r ._
! r
predict when pipes will
fail.The lnfoMaster@ risk �� - ,-�, �-�•��•.,�,
assessment model was Moraga
used to calculate riskqi 0-
scores based on an asset's
D City Boundaries
consequence of failure D CCCSD Service Area ��,
D CCCSD SOI ��
(e.g.,the amount of flow in vo, F ap
Major Highways
the pipe and its proximity Risk(By Grading)
\' "~
to schools, hospitals,and Low
major roadways)and Medium LowMedium
its likelihood of failure. Medium High
The likelihood of failure High San Ramon
is calculated from field
condition information,such Risk Map from the InfoMaster®Risk Assessment Model
as cleaning frequency or CCTV inspection score,and pipe age and material.
• Pump stations- Pump stations were evaluated with visual inspections and
data collected by the CWMP team and Central San staff during field visits to
the 16 pump stations owned by Central San.
• Force mains—Force mains were evaluated using available force main
material and age data as well as risk analyses performed by Central San for a
previously completed Force Main Asset Management Plan.
8 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
$60.0 25 reduce routine manual cleaning of bar
^ (D screens,replacing backup generators
In $50.0
0 20 E and original diesel engines from 1959
4-1
E $40.0 15 (D at Moraga and Orinda Crossroads,
expanding diesel engine day tank
4-1
0 $30.0 10 capacity at Orinda Crossroads,fuel
0 system improvements,miscellaneous
o $20.0 -- - - 5
pump/valve/piping im rovements,and
p
o $10.0 0 > other mechanical,safety,electrical,
>
and instrumentation improvements.
$ CO M O N CO t LSA CO r- CO 07 O N CO t LSA C9 I--
N N N hl N hl N hl N hl M C`7 co co co M M M Force Mains
O O O O O O O O O O O O O O O O O O O O
N N N hl N hl N N N N N hl N N N hl N N N N
-Total Project Cost Total Gravity Sewer Replacement Length Force mains are pressurized pipelines
20-Year Gravity Sewer Replacement Schedule that convey wastewater from the
pump stations to a high point,where
Gravity Sewers sewers will need to be replaced over it can then flow by gravity through
y
Central San's gravity sewer system
the next ZO ears. gravity sewers to the treatment
plant.Central San manages 31 force
pipelines range from 4 to 102 inches in Pump Stations mains with a combined length of 22.8
diameter.The newest sewers are made g
Pump stations convey wastewater miles.When the collection system
of polyvinyl chloride(PVC)pipe,high flows from where the topography condition assessment waserformed
density polyethylene(HDPE)pipe,and p
does not allow flows to be conveyed the force mains were not accessible
reinforced concrete pipe(RCP).Older by gravity alone.Central San operates for inspection.To obtain a better
pipes are made of vitrified clay pipe p
the 16 pump stations it owns as well as understanding of the condition of
(VCP), reinforced concrete pipe(RCP), 3 privately owned stations in Orinda. the force mains a phased force main
asbestos cement pipe(ACP)and, in a �
Because pump stations collect large inspection program is recommended.
few areas,steel pipe. amounts of wastewater and are The ro inspection ram would
p program
Based on available CCTV scoring typically located in low lying areas establish risk scores for each asset,
data,around 70 percent of the near creeks and other waterways,the prioritize replacement needs,and
collection system pipes are in excellent equipment at these facilities must ultimately establish a renovation
condition and approximately 30 reliably convey wastewater flows to program.Until then,force main
percent have some defects,with avoid overflows. Many facilities are renovation priorities are based on a
an overall condition of"okay"to in tight spaces,without the ability previous Central San risk assessment
every bad,"in which case immediate to store wastewater for extended based more on qualitative force main
replacement is recommended. periods when equipment is down information such as material and age.
Based on available pipeline cleaning unexpectedly.
frequency data,around 30 percent The condition assessment identified }.
of the system experiences routine $33 million in pump station renovation
_ .
s
root intrusion,grease buildup,and
projects p ro�ects to be completed in the
stoppages or blockages and is on a `
near-term(0 to 5 years)to maintain
less than 12-month cleaning cycle, - ��-
operational reliability.The most critical
with 3 percent requiring cleaning every improvements are needed at the ■
few months.Another 15 percent is Fairview Maltby, Moraga,a and Orinda
cleaned every 12 to 18 months,and the Crossroadsum stations.These
p P
remaining 55 percent is on a cleaning improvements include rehabilitating
-~
p g
cycle between 18 and 60+months. or replacing corroded buried steel
Using the InfoMaster® risk assessment pump station dry pits at Maltby and
tool,around 265 miles of gravity Fairview,adding grinders at Moraga to Fairview Pump Station
COMPREHENSIVE WASTEWATER MASTER PLAN 9
Capacity Assessment for Gravity Sewers areas of development for the smaller diameter sewers(<10
To identify hydraulic capacity deficiencies,the trunk sewer inch),but those are evaluated case by case since they are
system was analyzed for a peak wet weather flow(PWWF) not within the current modeled network.
based on a 10-year sewer system event,meaning that In most cases,the approach modeled for relieving the flow
theoretically the event would have a 1 in 10 year,or 10 restrictions was to replace the deficient pipe with a larger
percent,chance of occurring each year. one. However,in some locations,adding new relief sewers
The system capacity was assessed using a newly was more cost effective.These relief sewers divert excess
implemented hydraulic model of the system developed with flows from the deficient sewer to nearby sewers with
the InfoWorksT"' ICM software.The modeled network has sufficient capacity to convey them.
over 290 miles of trunks and interceptors and was calibrated
with flow measurements taken in the 2015- T
Legend la rtl nee
2016 wet weather season with 70 temporary Fa I rVl
Modeled pump stations ,.
flow meters and recorded rainfall amounts
Modeled Gravity Sewer
from five rain gauges.Using established
<' [Waltby
Force mains Clyde
design criteria,the gravity sewers in the -f �
a
model were allowed to surcharge during the CCCSD Wastewater
10-year event,meaning the water level was Treatment Plant
Acacia
allowed to rise above the top of the pipe
Concord
and into the manholes, but not allowed to Lower Qrl nda
Industrial
ove rfl ow. ; u
Sewers within the modeled network where _A
the levels in the manholes rose to within 5
feet of the ground surface during the event
ti
r
��{1�` .l4�„
were deemed capacity deficient.According H _ �.'A; }
to the model,approximately 7 miles of sewer
pipes are capacity deficient for the design f
wet weather condition,over 50 percent ..
� r
less than what Central San's previous,less
accurate model predicted,which also did not
allow for modeling water levels throughout
thei es and manholes.This new model ` Moraga
p p �}
helped eliminate four capacity-related
capital projects. Orinda
Crossroads
Aside from the North Concord system,
which will see additional flows when the 1� �-► ~`
Concord Community Reuse Area(formerly '
the Concord Naval Weapons Station)starts
to develop,Central San's modeled network
t � }
has sufficient capacity for existing and future
dry weather flows including daily peak
flows,to accommodate the planned growth
throughout the service area.Therefore, 0 1
.��,'fy
2 4 Miles
I
AaYrmajor capacity improvements are required Modeled Trunk Sewer System
7 ?
.� U
only to correct flow bottlenecks in the Figure CS 20.1
CENTRAL CONTRA COSTA SANITARY DISTRICT
COLLECTION SYSTEM MASTER FLAN
h
system under wet weather conditions. Minor - ?Rx -
improvements may be required in localized Mode/ed Trunk Sewer System
10 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
The model also confirmed that the diffusers and plenum are less The sludge dewatering
modeled pump stations have adequate efficient than modern diffuser centrifuges and cake pumps
firm capacity with the largest pumping technology,and they are nearing are obsolete.Spare parts are
unit out of service to convey flows for a the end of their useful life. becoming difficult or impossible
10-year event. The steam-driven aeration to acquire.To maintain reliable
blowers are inefficient and cannot dewatering options,these
Treatment Plant laced retems need to be s
be turned down to match low systems p
Condition Assessment within the next few years.
air demands during low flow
The treatment plant's condition was conditions. For optimal efficiency, Ongoing replacement of old
assessed with a team of Central San's the air piping and diffuser system or non-functioning mechanical
Operations and Maintenance staff and should be replaced when aeration equipment(piping,valves,
consultant discipline specialists for blowers are replaced so they can and gates),electrical support
structural,mechanical,electrical,and be properly designed as a system. equipment,and instrumentation
instrumentation evaluations. devices is required to maintain
The secondary clarifier concrete
Key findings include: tanks are in good condition,but stable,reliable operation.
Some concrete renovation the sludge collector mechanisms
0 Elam
and RAS pumps are over 40 years
work is needed, but all concrete ` - 4
old and should be replaced within ' r Gxvow
tanks and structures are in p '
rte.e,
3
the next 15 ears.
good condition and do not need Y u
F
mayor structural upgrades or The DAFT tanks and skimmer
replacement in the next 20 years. arms were recently renovated;
r
E 4 F
however,the sludge collector _ �'"
Each of the two Multiple Hearth �. � ,
Furnaces(MHF)has an estimated mechanisms were not upgraded
and will need rehabilitation within -_: w
20 ears of remainingserviceable
life. Despite being 35 ears the next 15 years.
p g Y
old,the MHFs have significant The ultraviolet disinfection system
remaining life because Central requires significant ongoing yx
��y. a StdL+y. yL
San alternates operation from maintenance and cleaning,and z
one MHF to the other each many elements of the electrical
year,which allows performing and control systems need to be
56r...
annualreventive maintenance replaced.The UV disinfection +�
p p - �
on the offline furnace.Several system should be replaced within
improvements will be needed the next 5 ears or so. t r` Y
p Y
over time to keep the MHFs The SCADA and PLC control Concrete Repairs are Necessary
operational and to replace MHF
systems function adequately.
support equipment- however y r
ppRoutine upgrades are being
d
pg g
those improvements are not completed to ensure reliable
p _ A
considered significant enough to
operation. However,a major
abandon the furnaces. SCADA controls replacement will
NO
Air piping to the activated sludge be required within the next 15 WIWI
I -
tanks has significant leaks. years.
Additionally,the ceramic aeration'
Leaks in Air Piping Need Renovation
COMPREHENSIVE WASTEWATER MASTER PLAN 1 11
CAPACITIES OF LIQUID STREAM PROCESSES—AVERAGE DRYWEATHER FLOW(ADWF)
pAverage Flow and Loading Peak Flow and Loading
Conditions Conditions
apacity(l) Capacity(') apacity(l) Capacity(') Projected
Unit ' o - mgd mgd mgd mgd A1 mgd
AME
Primary and Secondary Treatment
(PST,Aeration tanks, Secondary 54 48 44 43 41
Clarifiers)
Notes:
Abbreviation:PST= Primary sedimentation tanks
(1)Total Capacity is calculated with all units in service,using the average peaking factor from the last five years.Firm Capacity is calculated with
either 1 PST, 1 Aeration tank,or 1 Secondary Clarifier offline at a time,using the average peaking factor from the last five years.
(2)Total Capacity is calculated with all units in service,using the maximum peaking factor from the last five years.Firm Capacity is calculated with
either 1 PST,1 Aeration tank,or 1 Secondary Clarifier offline at a time,using the highest peaking factor from the last five years.
Capacity Assessment for average and peak conditions,
For each treatment plant process, assuming the flow to the secondary
treatment performance and capacity clarifiers is distributed evenly.
were assessed for wet weather and To reliably maintain an even flow
dry weather loading conditions.A distribution,a flow splitter structured is
customized BioWin process model, recommended.
calibrated to Central San's process Wet Weather Capacity
data,was used for the capacity Peak
process performance,hydraulic
assessment.
capacity,and rated pumping capacity
Liquid Stream Capacities were used to identify capacity needs
Dry Weather Capacity to accommodate flows generated by a
Because the primary and secondary 20-year storm flow event.
treatment processes are linked,
Total Capacity Deficiency
the overall plant capacity was 300 N Total Capacity
evaluated with these processes Required ■ Firm Capacity
Influent Pump 1 Capacity Deficiency=6 mgd(Firm Capacity Required)
combined.Using this approach, E Capacity= 2 Capacity Deficiency=60 mgd(Firm Capacity Required)
250 230 mgd
the dry weather capacity was o 3 Capacity Deficiency=27 mgd(Total Capacity Required)
LL
estimated for two conditions: % Required Primary
200 Treatment
it 00 conditions"and"peak a Capacity
170 mgd
conditions."'The capacity for
aD Required Secondary
average conditions was calculated 150 Treatment Capacity
e uired = 127 mgd
Req
from the average loading and o Bypass Pump
flow peaking factors over the past 100 Capacity
60 mgd
five years. For peak conditions,
the capacity was estimated by
applying the highest peaking o 50
factor that occurred in the last five Q 2
years. 0
cn Q ' M� Q ' N� E M �E U) � � -0 �� E
E ` c inE ` E v) o� M 0 � � � � � O Q) �
The analysis showed that the �; �, m m � �� w
U U � � ~
primary and secondary treatment � 0 M z
processes have sufficient capacity n Q D
p p Y Capacities of Liquid Stream Processes-Peak Hour Wet Weather Flow
12 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
PEAK HYDRAULIC CAPACITIES FOR LIQUID STREAM PROCESSES
Total Capacity, Firm Capacity, Projected Flow, Capacity
WWTP Unit Process mgd mgd mgd (2035) Deficiency('),mgd
Mechanical Screens 270 135 230 None
Influent Pump Station: Condition 1 To Preair: 236 To Preair: 118 N/A(3) N/A(3)
Influent Pump Station: Condition 2 To Preair: 236 To Preair: 164 To Preair: 170 6
Influent Pump Station: Condition 3 Bypass: 85 Bypass: 0 Bypass: 60 60
Pre-aeration Tanks 170 85 170 None
Primary Sedimentation Tanks 1700) 1700) 170 None
Primary Effluent Pumps 225 150 127(2) None
Aeration Tanks/Secondary Clarifiers 1000) 1000) 127(2) 27
UV Disinfection System 1000) 1000) 127(2) 27
Final Effluent Pumping 127(4) 127(4) 127(2) None
Notes:
Abbreviation:mgd =million gallons per day
(1)Based on hydraulic capacity.
(2)Required secondary treatment capacity dictated by PICS-MOST storage event model results.
(3)This condition is not applicable for this weather scenario.
(4)Capacity of the final effluent pumping is limited hydraulically by the outfall.The rated capacity of the final effluent pumps and standby
effluent pumps is higher.
(5)Capacity deficiencies are based on redundancy criteria and requirements.
L ; x
Wet Weather
w ;
(� Wet Weather Holding
Holding Basin A South $
w Basin A North (Capped) ! ;-
Ile- R f
of
l
01
ti
„./
Contaminated
Soil(Capped) Jbi
AV
t � t
ti Flow
Control
Structure ►
Wet Weather
Holding Gunite
Basin B Channel : "►■yah
� � ►►,,►. �,,►s � ,,fin,,• ,:�
Cr
r. ...rte_ -:ter, - 5 ��. � ►► �" .
,
_ • 1
f
w ae,
Wet Weather
Holding
r = Basin C
Ablo
Wet Weather Holding Basin Site Plan
COMPREHENSIVE WASTEWATER MASTER PLAN 13
Wet Weather Holding Basin — Influent(mgd)
(WWHB)Storage Volume 350 •Treatment Capacity(mgd) 1000 n
The WWTP can receiveeak Flow to Storage(mgd) o
c�
p 300 Drain back from Storage(mgd) 900
flows that exceed the capacities Discharge Flow(mgd) 800 �
of the primary and secondary 250 Storage Volume(mg) 700 .o
treatment processes in very 600 'E
a rg e sto rm eve nts.To p reve nt M 200
-- — ------- — -- -------- 500 �
overloading,excess wet weather E • E
g 150 ♦♦ 400 2
flows are typically diverted to up o Apa ` ♦ O
100 300 >
to three Wet Weather Holding (D
200
Basins(WWHBs)for temporary 50o
100 o
storage.The stored flow is c/)
returned to the treatment plant 0 0
Storm Duration
after the storm recedes.The
available volume in the WWHBs, PICS MOST 20-year storage event simulation
along with the rated capacities of Required PeakWetWeather For a 20-year storage event(i.e.,1
the treatment processes,determines Secondary Treatment Capacitv in 20 year,or 5 percent,chance of
the total volume of wastewater that The PICS-MOST model(Program that volume of wastewater requiring
Central San can accommodate during g
for Infiltration/Inflow Continuous treatment or storage each year),and
a storm event without having to Simulation/Model for Optimization using an available WWHB storage
discharge untreated flows. p
g of Storage and Treatment)was used volume of 122.7 MG(after installing
There is not enough land to expand to simulate combined flow-storage a new overflow weir),the secondary
the basins'footprint. In addition,the volume events at the WWTP.The treatment and disinfection process
levees cannot be raised because the model uses historical rainfall data must be able to handle a peak hour
soils do not appear to be suitable and influent flow data to relate wet wet weather flow of 127 mgd.This
for supporting additional weight. weather flows at the treatment plant to represents a capacity deficiency of 27
However,the total available storage different storm events,and compares mgd when compared to the 100 mgd
volume can be increased by 28 percent the volume of total wastewater capacity of the existing secondary
by constructing a new overflow generated from the storm that treatment and disinfection processes.
structure on Basin B that could allow needs to be managed with available Solids Stream Capacity
for Basin B to be reliably filled to within treatment and storage capacity.The
Capacities for solids treatment
two feet of the top of its levee.The results from the model can determine
processes were estimated from the
current wooden stop logs are not as the required treatment capacity to
maximum monthly solids loadings
reliable as a permanent structure,and properly handle the flows from any criteria and maximum day solids
should not be considered reliable for given storm event. criteria for solidsum in facilities and
operating at a water level in Basin B p p g
p g were compared to the projected solids
higher than the top of the adjacent loadings due to population growth.
Basin C levees.With this structure in
place,the total storage volume in the
WWHBs(while maintaining a typical
safety factor of 2 feet of freeboard)will
increase from 95.8 million gallons(MG)
to 122.7 M G.
14 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
CAPACITIES FOR SOLIDS STREAM PROCESSES
Projected Flow/ Flow/Load Basis Capacity
Solids Unit Process Total Capacity Firm Capacity Load(2035) for Capacity Deficiency(")
Primary Solids/ 520 gpm 390 gpm 280 gpm(1) Peak Day Flow None
Recirculation Pumps
WAS Pumps 5,800 gpm 3,800 gpm 2,770 gpm(2) Peak Day Flow None
DAFT without polymer 122,400 Ib/d 81,600 Ib/d 83,500 Ib/d Max Month Load 1,900 Ib/d(8)
DAFT with polymer 193,000 Ib/d 128,700 Ib/d 83,500 Ib/d Max Month Load None
TWAS Pumps 450 gpm 450 gpm 310 gpm(3) Peak Day Flow None
Sludge Storage 1.17 MG N/A 1.18 MG(4) Max Month Load Negligible
Centrifuge Feed 920 gpm 645 gpm 600(3) Peak Day Flow None
Pumps
Dewatering 600 gpm 450 gpm 460 gpm(3) Max Month Flow None
Centrifuges
Cake Pumps 180 gpm 135 gpm 82 gpm(5) Peak Day Flow None
Multiple Hearth 54.8 dtpd(7) 54-61 dtpd Average Day Load 0 to 6.2 dtpd
Furnaces 60 dtpd(9) 88-99 dtpd(6) Peak Day Load None(10) None(10)
Steam Supply 96,000 Ib/hr 38,500 Ib/hr 43,500 Ib/hr Peak Day 5,000 Ib/hr
Notes:
Abbreviations: TS=total solids;Ib/d or Ib/hr= pounds per day or hour;gpm=gallons per minute;dtpd=dry tons per day
(1)Primary Solids flow at 4%TS.
(2)Waste Activated Sludge(WAS)flow at 0.3%TS.
(3)Thickened WAS(TWAS)and combined solids flow at 3%TS.
(4)Equalization of peak shaving volume that was calculated based on the full incineration capacity permitted solids loading that could be reached prior to 2035.
The volume to store is the difference between the maximum month solids loading and the amount that is permitted to be processed by incineration.
(5)Cake flow at 23%TS.
(6)Range in values show plant reported loading as lower range and model predicted loading as higher range.
(7)Based on the Title Vpermit limit of 20,000 dry tons per rolling 365 days.
(8)There is no capacity deficiency if decreased performance of Dissolved Air Flotation Thickeners(DAFT)below 95 percent capture is tolerable.
(9)Based on the Title V permit limit.
(10)Peak solids loads are effectively managed by storing blended sludge in the Sludge Blend Tank(SBT)and/or Emergency Sludge Storage Tank(ESST).
(11)Capacity deficiencies are based on redundancy criteria and requirements.
Capacity Assessment Findings and Conclusions Summary
• Overall Dry Weather Capacity— All Influent Pump Station A sixth UV Disinfection and Final Effluent
the liquid stream processes have influent pump is recommended Pipe i Low lift pumps are
adequate capacity through 203S to provide firm, reliable pumping recommended to relieve a
under dry weather conditions. capacity(i.e.,adequate capacity hydraulic restriction near the
• Wet Weather Holding Basins— A with one pump out of service)to the UV disinfection effluent channel
new weir structure on the Basin B pre-aeration tanks and to the wet during wet weather events,and
spillway is recommended to gain weather holding basins. a parallel 72-inch final effluent
an additional two feet of reliable Secuiidary Clarifieib- Two additional pipe is recommended to reduce
storage in Basin B.This will result clarifiers are recommended to headlosses to accommodate
in a maximum available storage provide the required 127 mgd peak a 127 mgd peak secondary
volume of 122.7 MG for all three secondary treatment capacity treatment capacity.
holding basins combined(with needed to accommodate a 20-year
two feed of freeboard). storage event.
COMPREHENSIVE WASTEWATER MASTER PLAN 15
Not Shown: Add Two
Replace Stop Logs at Add
Basin B Spillway with Add Two Anaerobic Fourth
Weir Structure Secondary Digesters I` DAFT
Clarifiers
O
a _ Add Sixth
Influent
Pump
A.,
x. O
Ir
so
• rr
r
a.
A
y ``I{{II II II pp Si[iTi s va,
-
4. .Y1 R —1 J71I.I.I-1._.V.1 �Y' i.-••�,:. rri(_[l fff '4
■■ ,off dr
n t, JJ 1JJJJ J�NR
- --- � � waste heat recovery boilers stem.
: J_,. Landfill as is used primarily as
g p Y
...�'
supplemental fuel for incineration,
Reduce UV Hydraulic ' '. i Reduce Headloss in
�t
Restriction Using Low : ,:, Final Effluent Pipe and natural gas is used primarily in
Lift Pumps4 - yyL with a Parallel Pipe {`yr the cogeneration unit to generate
`���\� "Y'G'! ��•!' .. 4�r :� � .4" p Iii
-� - electricity.
Major Capacity Expansion Projects From 2014 to 2015,the treatment
• DAFT— the dissolved air Energy Balance plant consumed electricity at an
flotation thickeners may not have average rate of 2,620 kW.The natural
y Aplant-wide energy evaluation was
adequate capacity.After the new gas cogeneration system generated
qcompleted using 2014 and 2015
centrifuges and cake pump aretreatment plant operating data. approximately 95 percent of the
installed,a polymer optimization electricity needs(approximately 2,500
test is recommended to evaluate The treatment plant imports energy kW),and PG&E supplied the remaining
whether polymer should be added from three sources:electricity,natural needs(120 kW).Solids handling,
as loadings increase to maintain gas,and landfill gas. Energy from process pumping,and UV disinfection
the targeted DAFT performance. wastewater solids is also recovered use most of the electrical power
If polymer optimization is not through combustion in the MHF and supplied.
successful or the declined DAFT
performance is not acceptable, Odor Control
a fourth DAFT will be required in HVAC Screening
the future. Final Effluent Pumping .
• IVIHFs— The current practice
Primary Treatment, Incineration, 16%
is to operate only one multiple Thickening
hearth furnace(MHF)at a time. Other
With one unit in service,projected Service Air
annual average solids loading Dewatering,6% Influent °
will exceed the MHF permitted Pumping, 13/o
throughput limit before 2035. In Secondary
addition,the MHFs do not have Treatment,6%
enough capacity for the peak Other Solids PrimaryEffluent
da loadings.The existing Sludge Processes,6% Pumping, 11%
Blend Tank and Emergency
Sludge Storage Tank will continue 3W water,7% UV, 10%
to be needed for both emergency Filter Plant
storage and for temporarily (Recycled Water),7%
storing solids during high peak Treatment Plant Energy Consumption,by Process Area
day loading conditions.
16 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN MAY 2017
Energy Balance Findings and Recommendations
1. Greenhouse gas emissions 3. Central San's objective for the
PG&E
can be maintained below the treatment plant is to achieve Net 0.48%
California Air Resources Board Zero Energy. Net Zero Energy
anthropogenic cap-and-trade is defined as"using enough Solids to
threshold of 25,000 MT CO2 per renewable energy to satisfy Incineration
year by maximizing landfill gas annual energy consumption 34%
usage as long as possible and requirements."Central San will
continuing to recover energy strive to achieve Net Zero Energy
from the wastewater solids.The by improving energy efficiency in
cogeneration turbine provides a the following areas:
cost-effective way to generate Decoupling the solids and
electricity on site, particularly liquid processes by replacing Landfill Gas Natural Gas
with the current low price of the current energy recovery 13% 53%
natural gas. It also significantly system and steam-driven
Energy Source Profile at Treatment
reduces imported grid electricity
aeration blowers with an Plant
from PG&E. Organic Rankine Cycle(ORC)
2. Landfill gas production is turbine and high efficiency
expected to decline overtime electric blowers and new
as the landfill ramps down its efficient diffusers.
operation.In the future, more Adding anaerobic digestion
efficient solids handling and upstream of the MHFsto
energy recovery facilities will produce biogas and generate
provide a sustainable way to electricity.
minimize costs and continue to Replacing the existing
operate below the cap-and-trade cogeneration turbine with a
threshold—even if landfill gas is larger,more efficient turbine.
no longer available.
Adding renewable energy
sources,such as solar,wind,
and co-digestion of imported
high-strength waste(HSW)
such as fats,oils,and grease
(FOG).
COMPREHENSIVE WASTEWATER MASTER PLAN 17
5. NAVIGATING THE FUTURE REGULATORY ENVIRONMENT
CWMP recommendations for the EXPECTED BACWA NUTRIENT DISCHARGE LIMITS AND
treatment plant were developed to COMPLIANCE SCHEDULE
meet existing regulatory requirements, Assumed
and to provide the flexibility toJOA L Concentrations, mg/LSchedule
meet potential future regulatory Total Initiate Compliance
requirements. Key findings and 'nia Nitr" Phosphorus -Design Deadline
recommendations are listed below: Level 1 Optimize nutrients (no exact limits) 2019 2024
NuLlient LirlII«: Assumptions for Level 2 2 15 1 2027 2037
nutrient limits and compliance Level 3 2 6 0.3 2037 2047
schedules were based on the
Bay Area Clean Water Agency Future Solids Management The However,a more robust
(BACWA)Scoping and Evaluation current practice of incinerating expansion of solids handling will
Plan for potential nutrient wastewater solids and ash reuse be required. In addition,over
reduction. as a fertilizer amendment is a the next 5+years,Central San
sustainable option in the current will explore other innovative and
• IVlicroconstituents and CECs: regulatory environment and is emerging solids handling and
The current trend of increasing expected to remain so over the resource recovery technologies
monitoring requirements and planning period.Solids loading that may prove to be viable long-
regulation of microconstituents projections are expected to be term solids handling solutions.
and other constituents of higher than the MHF permitted
emerging concern(CECs)could Future Recycled Water Use- Central
average annual capacity within San's current recycled water
lead to new limits for Central San the next 20 years;therefore,to
in the future. However,since the production is five percent of the
increase capacity,diversifying wastewater flow processed at
scope and timing for potential solids treatment and reuse
limits is still uncertain,new the treatment plant.To expand
options will be required.Central recycled water production
facilities to target CEC reduction San's emergency sludge storage
were not included in the CIP.To and use,Central San will need
and loadout facility,where to develop agreements with
ensure adequate space for these dewatered,unstabilized solids
facilities,a future CEC treatment the agencies responsible for
can be temporarily hauled offsite purveying water within Central
system was included in Central to another treatment facility,is
San's site plan. San's service area and possibly
the current contingency plan. partner with water purveyors
outside Central San's service area
that may have a more immediate
need for water.
18 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN MAY 2017
• Biosolids Reuse:The ability to use biosolids as landfill alternative -tea.. IT
daily cover will decline significantly over the next few years.
Recent California legislation requires a 75 percent reduction `„ 1
of organic wastes sent to landfills by 2020(AB 341).The State
will also eliminate diversion credits for green waste used as Ar
4
alternative daily cover by 2020(AB 1594)and will require 100
percent diversion of organic waste from landfills by 2025. �r
i
rti
Regional biosolids reuse practices may need to change as .�
these landfill diversion goals are in place,and wastewater
utilities may need to compete for other biosolids reuse options, --
which will likely increase the cost to reuse biosolids. By using `
MHFs to process the solids and reusing the ash as a fertilizer -�
amendment,Central San can avoid this competition. .. _
• Air Enobsiums. Several air emissions regulations and anticipated •� r
regulatory changes are motivating Central San to invest in new .
air pollution control equipment.These regulations include:
Additional investment in the MHFs will eventually designate
them as modified sewage sludge incinerators(SSI)which , Y
would trigger air emissions upgrades to provide the best Maintaining Equipment Ensures Regulatory Compliance
available control technology(BACT).
Draft Regulation 11, Rule 18 would require reducing toxic
air emissions that pose a health risk to the public.Updated
risk assessment methodology will require a Health Risk
Assessment(HRA)at the treatment plant to ensure cancer
risk from toxic air compounds does not exceed 10 in a
million.
Future PM2.5 limits(i.e.,fine particulates)may be imposed
because of the Bay Area's non-attainment status for 24-hour
PM2.5.This would require additional air pollution control
equipment,such as a wet ESP.
Although Central San operates under the new EPA SSI
rule, replacing the existing outdated air pollution control
equipment with new equipment will enable more reliable air
emissions compliance.
COMPREHENSIVE WASTEWATER MASTER PLAN 19
6. PLANNING FOR MORE RESILIENT FACILITIES
rainfall totals over the next 20
; = �` ---- years. However,the frequency of
_A7
extreme peak wet weather events
■ -__ is expected to double by the
- year 2050 and triple by the year
2100. By designing for a 500-year
4 u f
=� event,the higher levee will allow
°4.. for some additional protection
against potentially larger storm
surges.
Wet Weather Holding Basin B During a Recent Storm Event
The influent pump station is
Flooding Resiliency ranging from one to three feet. most vulnerable to flooding.The
In 2005,a 40-year storm caused The California Department dry pit for the influent pumps
Pacheco Creek to overtop its levees of Water Resources(DWR) and motors are below ground,
just upstream of the WWTP. Flooding standard is to protect against which would flood if the levees
at the treatment plant was narrowly a 200-year water level with breach.The pump motors are
avoided as the levels in Grayson and three feet of freeboard,with close-coupled to the pumps
Walnut Creek rose to the brink of the allowances for sea level rise due and are at a low elevation that
levee crest. to climate change.Central San could flood.Although raising
is collaborating with the FCD to the levees will reduce the risk of
To avoid catastrophic failure,flood raise the levees along Grayson son flooding from the creeks flood
protection is critical.If the levees
overtop or breach,the plantwill flood, and Walnut Creeks toprotect the water from the surrounding causingover$150 million in damagearea can still accumulate in the
and site from a 500-Year storm with long-term interruption of wastewater three feet of freeboard. dry pit that houses the electric
treatment service.The treatmentp lant's Climate change is another motors.A leak in the influent
most susceptible areas are the below- potential threat to the treatment pump piping can also cause
round utility tunnels.The tunnels plant. Long-term regional catastrophic flooding of the dry
g Yit and
contain critical equipment,such as precipitation models predict p pump failure.The influent
influentum s and motors,primary rimar little change in average annual pumps are critical because they
p p
effluent pumps,effluent pumps,solids PROJECTS TO MITIGATE FLOOD RISKS
handling support equipment,and the
MHF center shaft drive. Project '
st Estimate
Walnut&Grayson Raise the levee along Walnut&Grayson
The nearby flooding event in 2005 Creeks Levee Creeks to provide protection for a 500-year $1,100,000(')
prompted the Contra Costa County Rehabilitation flood event.To be complete by 2018.
Flood Control and Water Conservation Replace Influent Provide motors that can operate
District(FCD)and Central Santo p temporarily in case of dry pit flooding due
Pump Motors with to wet well leak or in $1,186,000(l)
i
initiate a joint interim project in 2007. Immersible Motors piping g failure.To be
The project included de-silting the
Notes: complete by 2021.
Walnut Creek channel and raising
the levees aloe Walnut and Gra son (1)Existing District project DP7341.Cost is based on the District's Capital Improvement Budget and 10-
g y Year Plan adopted June 2,2016.
Creeks,protecting against a 100-
(2)Recommendation by the CWMP.Cost is based on a 3/30/2016 quote from Gent Components and TM
year storm with a range of freeboard No.G-3-Basis of Cost Estimates.
20 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
are required to pump incoming • Standby Power Facility Operational Vulnerabilities
wastewater to the treatment Strengthening frame connections The following recommendations are
plant for processing and to send and installation of knee braces at aimed at maintaining and improving
wastewater to the holding basins the existing moment frames. operational resiliency at the WWTP:
during peak wet weather events.
Central San is constructing seismic Continue annual updates of
To guard against this threat,the
improvements to the Pump and Blower Central San's Contingency and
pumps will be equipped motors
that can be immersed for short
Building and is further evaluating Spill Prevention Plan.
seismic improvement needs at the
durations. Complete aplant-wide
Solids Conditioning Building.The
vulnerability assessment with
Seismic Resilient remaining seismic improvements are
Resiliency key District operations and
Accordingto Central San's 2009 plant- scheduled for completion over the next maintenance staff for each
wide seismic study,most of the major 10 years. process area to identify Y an Y
buildings will likely experience damage Process equipment and piping new emergency response plans,
if a 6.7 magnitude earthquake occurs throughout the WWTP are also recommended emergency
on the Concord-Green Valley fault. at risk of damage and long-term contracts,changes to policies
Per California Building Code,a 6.7 service interruption due to seismic and programs,and any new
magnitude earthquake corresponds events.Since this equipment has not capital improvement projects.
to a 475-year recurrence interval. been thoroughly evaluated,seismic Incorporate recommendations
Damages to structures would weaken evaluation of the mechanical and into the Contingency and Spill
the frames that support the building electrical equipment in each building Prevention Plan and Capital
roofs and intermediate floors,and and of major piping in the utility Improvement Plan.
many buildings would be unsafe tunnels is recommended. Decouple the secondary
for plant staff access afterward. For treatment aeration blowers
several days or months,buildings The 2009 seismic study did not assess
water-retaining structures,such as from the solids handling and
would require repairs and treatment the steam system.Although the
operations could be significantly the primary sedimentation tanks,
A/Ntanks,and secondary clarifiers. steam-driven aeration turbines
limited,limiting the ability to manage and waste heat recovery system
and treat wastewater.The 2009 study The 2009 evaluation was also based
on building codes that have changed are sustainable energy solutions,
recommended seismic upgrades for they create a complicated and
several buildings at the treatment significantly.Additional seismic
evaluation is recommended for water- vulnerable interconnection
plant. retaining structures. between the various processes
Since the 2009 report,Central San
completed retrofits of the following
g
buildings: x. f
The Headquarters Office Building
Installing additional interior - ' w
moment frames anderimeter r
p �
posts. .
r
• Household Hazardous Waste �6
V
Collection Facility—Modifying
braces at the frames,installing
knee braces at the frames,and
adding a short collector member ,
at the location of the re-entrant
_ k
corner. Inspection of the Multiple Hearth Furnaces
COMPREHENSIVE WASTEWATER MASTER PLAN 21
and equipment.As previously mentioned,converting the waste heat from
solids incineration into power using an organic rankine cycle turbine and
using electric blowers instead of steam-driven turbine blowers would help
t= overcome this vulnerability.
• Consider constructing a second primary effluent gate.Currently,all flow
from the primary sedimentation tanks must go through a single gate to go
downstream for secondary treatment. If this gate fails when closed or at
an undesirable position,it can restrict flow and reduce level control in the
primaries.
• Install a dedicated raw bypass pump station and drainback pipeline for
reliable,simultaneous diversion of both raw screened effluent and primary
effluent during wet weather events.Currently,the ability to bypass these
Capita/Improvements are Needed for streams simultaneously is limited by the hydraulics of a shared bypass
Security pipeline.
Physical and Cyber Security
An initial review of security measures was completed for the CWMP.The
following are recommended capital improvements and studies to improve the
physical security:
Implement the security-related capital improvements identified for the
WWTP and pump stations as outlined in a confidential report provided to
the District.
Complete a more comprehensive security study(currently under progress)
for all major facilities that utilizes the principles of AWWA J100 Risk
Analysis and Management for Critical Asset Protection methodology
(RAMCAP®J100).The RAMCAP method is a 7-step process: 1)Asset
Characterization;2)Threat Characterization;3)Consequence Analysis;4)
Vulnerability Analysis;5)Threat Analysis;6)Risk/Resilience Analysis;and 7)
Risk/Resilience Management.This study will include recommendations for
improving the District's overall security program.
Continue to actively track the latest trends in cyber security threats and
prevention.
Initiate an ongoing,annual capital improvement project to assess cyber
security threats and implement cyber security improvements as needed.
22 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
7. RECYCLED WATER NEEDS AND OPPORTUNITIES
Recycled water demands are
Rehabilitation of Aging Reliability Improvements
expected to increase over the next
ZO ears.Additional utility water, Infrastructure Replace one of the unused
Y Y
which is produced by the recycled The following improvements are oversized 300-HP Applied Water
water facilities,will be needed to recommended based on the condition Pumps with a new pump sized
accommodate potential future assessment: to match the existing 50-HP
treatment plant processes. In addition Applied Water Pumps;this will
p p Replace the filter media,
more recycled water will be required to provide pumping redundancy for
y q underdrains,filtered effluent
satisfylandscape irrigation demands current peak day recycled water
p g flow meters,instrumentation,
for the Concord Community Reuse controls and coagulant flash demands.
Project development.The projected mixing. Perform coagulant testing
average Title 22 recycled water to evaluate using alternative
Replace the Clearwell liner and
demand at 2035 is S.S mgd,compared replace the east cover. coagulants instead of alum.
to the current average demand of Coagulant testing and
1.6 mgd,and the projected peak day Upgrade or replace the electrical optimization may lower operating
demand at 2035 is 11.3 mgd versus support equipment for the costs and improve filter capacity.
the current peak day recycled water recycled water,filter plant,and
Add a cover to the west Clearwell
demand of 3.8 mgd. applied water process areas.
currently not covered or used
Replace chemical support system
components(coagulant and to provide redundant storage
sodium hypochlorite). and allow for routine draining,
cleaning,and maintenance.
PROJECTED RECYCLED WATER DEMANDS
Current
—.AA -d -
Future lir 617
and Utility -WaterM Water(2)
Redevelopment Futu - Zone 1-
Seasonal Average 1.6 1.4 2.5 0.8 5.5
(mgd)
Peak Day(mgd) 3.8 1.7 5.8 1.9 11.3
Notes:
(1)Based on data from 2013 to 2015.
(2)Future utility water demands assume the recommended alternatives for nutrient discharge,recycled water production,and solids
handling.
(3)Future Zone 1 demands represent the remaining potential flow to Zone 1 customers based on the District's agreement with
Contra Costa Water District.These demands are included for informational purposes only and are not included in the Total Future
Demands values shown.The District has not identified any other major users in Zone 1 that are not already connected and that would
meet the District's Board Policy(BP 019)project requirement for a 15-year payback.
COMPREHENSIVE WASTEWATER MASTER PLAN 23
- � • -- � Existing -
Recycled Water
Delivery Pumps 4
r
New West Existing East
Clearwell Cover Clearwell Cover
New Chlorine
Contact Basin
Existing
'7
Filter Plant .
New Filter
Pretreatment
s
_J
Existing
Backwash Tanky
4_
LEGEND
Existing
Forebays Existing Buried Pipeline
•' New Facilities
Recycled Water Facilities
Capacity Improvementp
All major recycled water treatment Add a Chlorine Contact Basin to an average of 35.5 mgd is available for
facility components were evaluated, expand disinfection capacity. additional recycled water production.
including applied water pumping, Expand chemical support Driven by California's drought,water
tertiary filters, backwash pumping, systems(coagulant and sodium conservation efforts,and Central San's
Clearwell storage,disinfection hypochlorite). long-term goal of zero discharge,
facilities,and recycled water delivery Central San is exploring opportunities
facilities.The following improvements Add filter pretreatment upstream to expand recycled water production
were identified to meet future recycled of the filters to improve water and help augment regional water
water demands: filterability when expanding supplies.
the capacity to meet Concord
Repeat filter capacity testing Community Reuse Project In 2016,Central San commissioned a
after rehabilitating the filters recycled water demands. study to identify wholesale recycled
and optimizing the coagulant to water opportunities.There are
confirm the reliable capacity of Expanding Recycled Water Use opportunities to offset raw water used
the existing filter plant. Current recycled water production is at neighboring refineries by supplying
Replace the applied water pumps limited by the Title 22 recycled water high-quality recycled water,export
with pumps sized to accommodate demands.Central San's projected recycled water to agricultural users via
projected peak day demands. average dry weather flow is 41 mgd the Delta Mendota Canal,or produce
Investigate potential Forebay and and projected average Title 22 recycled high-quality water for Indirect or Direct
Outfall hydraulic limitations on water demand is 5.5 mgd,meaning Potable Reuse(IPR/DPR)for water
applied water pumping. purveyors in the region.
24 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
The refinery opportunity appears to RECYCLED WATER CAPACITIES
be the most feasible recycled water Component Approximate Capacity, mgd
expansion option.The refineries Applied Water Pumping 4(1)
currently use a combined total of 20 Tertiary Filters 6 to 11(2,3)
mgd of raw canal water supplied by Backwash Pumping 25.8 gpm/ft2(4)
Contra Costa Water District(CCWD).
Supplying recycled water to the Disinfection: Clearwell Storage and Contact 6
Time Facilities
refineries would require treatment
u pg rades to remove ammonia and Recycled Water Delivery Facilities 5
possibly nitrogen and dissolved salts. Notes:
Because Central San understands (1)Current operational capacity is 4 mgd.To efficiently meet demands above 4 mgd,modifications
would be required,including adding VFDs on the 300 HP pumps and replacing the 50 HP pumps with
that recycled water can play a key larger pumps.The applied water pumping capacity corresponds to a recycled water production of 3.6
role in augmenting limited regional mgd assuming 10%of filter feed is ultimately used for backwashing(4 mgd/90%=3.6 mgd).
water supplies,recycled water (2)Filter capacity based on performance during April and May 2016 filter testing.6 mgd capacity with a
treatment upgrades were considered 24 hour minimum filter run time 95%of the time; 11 mgd capacity requires decreasing minimum filter run
in evaluating future facilities and time to approximately 14 hours.Capacity based on three filters in operation at a time.
developing future site plans. (3)Modifications,such as adding a new static mixer and instrumentation/metering improvements,
would be needed to achieve the filter capacity shown.
(4)Backwash pumps have adequate capacity to backwash one filter cell at a time.The maximum
backwash rate is close to the original plant design criteria of 25 gpm/ft2 and exceeds the current
backwashing rate of about 20 gpm/ft2.
COMPREHENSIVE WASTEWATER MASTER PLAN 1 25
8. MEETING FUTURE NUTRIENT REGULATIONS AND
EXPANDING RECYCLED WATER USE
Evaluation of Alternatives current) available.The following ass/ and environmental)and the fourth
Y gp
Treatment alternatives for liquids and fail criteria were used for the initial category(denoted by the +")is added
solids streams were identified for their screening: to include technical advantages and
ability to meet potential future nutrient disadvantages.
1. Is the technology proven/scalable
limits,strive toward net zero energy, to meet liquid,solids,and air Evaluation criteria for each category
diversify solids handling and biosolids regulations? were identified according to the CWMP
reuse options to meet the projected planning objectives.The evaluation
solids load,to supply recycled water 2. Does the technology fit within
site constraints? criteria were then further developed to
to nearby refineries,and strive identify performance parameters and
towards zero discharge.To evaluate 3. Does the technology maximize units of measure.
the alternatives,the%%universe"of use of existing facilities?In other
technology alternatives was first words,does it avoid abandoning The three liquids and three solids
screened.Treatment alternatives were facilities in good condition? alternatives listed below were
then evaluated from the list of viable evaluated during a workshop with
g
technolo ies. Triple Bottom Line Plus (TBL1 Central San staff from Operations,
Evaluation Maintenance, Planning, Regulatory,
Screening of Alternatives The"triple bottom line+"evaluation and Capital Divisions.
In December 2015,Central San held process was used to compare the
a workshop to evaluate the universe alternatives.The TBL+process
of alternatives,which is the broad evaluates how well alternatives meet
field of possible liquid,solids stream, the project's needs based on the three
and energy process technologies traditional categories(financial,social,
26 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
Preliminary Primary Biological ••- _ Effluent
RemovalTreatment Treatment * •W� 14 Management
Grit Removal Additional Primary MLE Granular Media Filtration: UV Recycled Water
Technologies Sedimentation Tanks(PSTs) •Deep Bed to Refineries
•Pulsed Bed
Grit Removal Chemically Enhanced Step-Feed 'ABW Ozone Recycled Water to DMC
•Detritors Primary Treatment(CEPT)
•Aerated Grit Basins Enhanced High-Rate Sequencing Disc Filters Public Access Reuse
•Vortex Grit Basins Clarification(EHRC) Batch Reactors Microfiltration/ �F Pasteurization (Recycled Water for
Landscaping)
•Eutek HeadCell Mechanical CAS+Denitrifying Filters Ultrafiltration Sodium Hypochlorite
•Grit King Primary Treatment (DeNF) (membranes) Discharge to Walnut Creek
(Discontinue Outfall
CAS+MBBR Fuzz Filters Peracetic Acid(PAA) to Suisun Bay)
Grit Washing Adsorption Y
•Classifier Continued Discharge
•Cyclone-Classifier Dense Sludge Clarification CAS+BAF MBR to Suisun Bay
•Eutek SlurryCup/Snail IPR/DPR
•S&L Turbo Washer Simultaneous Nitrification/ Ballasted Flocculation/
Primary Filtration DeN Oxidation Ditch Sedimentation
•Huber Coanda (ActifloTM) Recycle Water
•Other Variations or Integrated Fixed Film to Power Plant(s)
Primary Effluent Filtration Activated Sludge(IFAS)
Imitations of the Types
Listed Above
DAF Clarifiers MBR
Sidestream Treatment-
NAS
Sidestream Treatment-
CaRRB
Sidestream Treatment-
Annamox
Adsorption/Bio-oxidation
Ballasted Activated Sludge
Nitrite Shunt
NiDeMa
Zeolite Ammonia Removal
Universe of Liquids Treatment Technologies
Solids .. Processes
Anaerobic Stand Alone Alkaline Aerobic Emerging/
Digestion+SSI Digestion Stabilization Digestion Embryonic
ski 19M 191
Technologies
MHFs MAD+SSI MAD+Drying Direct Pyrolysis
(existing) Drying
Thermophilic Fluidized Bed Thermal Indirect
Reactor Hydrolysis+SSI Anaerobic Drying Gasification
Digestion
TPAD+SSI AG Hydrothermal
Anaerobic Liquefaction
Biological Enhanced Supercritical
Hydrolysis+SSI Anaerobic Water
(THP,etc.) Oxidation
Universe of Solids Handling Technologies
COMPREHENSIVE WASTEWATER MASTER PLAN 1 27
LIQUIDS ALTERNATIVES SOLIDS ALTERNATIVES
Alternative L1-MLE+ MF+RO: Expand activated sludge Alternative S1-FBIs: Replace MHFs with two Fluidized
process for biological nutrient removal(MLE or Modified Bed Incinerators(FBI).
Ludzack Ettinger)and add microfiltration(MF)and
reverse osmosis(RO)for refinery recycled water. Alternative 52-Digestion+ Dryer+FBI:Add anaerobic
digestion and drying followed by one FBI.
Alternative L2-MLE+MBR+ RO: Expand activated
sludge process for biological nutrient removal and Alternative S3-DigestionOnly:Add standalone
add membrane bioreactors(MBR)and RO for refinery anaerobic digestion with thermal hydrolysis to
recycled water. produce Class A biosolids that will eliminate the use of
incineration.
Alternative L3-IFAS+ MF+RO:Convert activated sludge
to integrated fixed film activated sludge(IFAS)and add
MF/RO for refinery recycled water.
At the workshop,the team scored the liquid and solids alternatives for each
category and objective. In the end,the team selected liquid stream Alternative
L-2-- MLE process for nutrient removal and the MBR process for recycled water
production for the refineries and solids alternative S-2--anaerobic digestion
followed by incineration,where the existing MHFs would be replaced with one FBI
when the MHFs reach the end of their useful life.
❑T1: Provide Reliability and Performance ❑ Sl: Protect Public Health and Safety
❑T2: Efficiency and Flexibility ❑ S2: Maintain Good Public Relations
■ F1: Capital Costs ❑ E1: Impact on Local Environment
■ F2: OEM Costs ❑ E2: Impact on Global Environment
S1 S21
LF 2
F2 I S!v
T2 T2 T2 _ T2 T2 T2
T2 T2
T1 T1 T1 T1 T1 T1 T1 T1
Ideal Alt Ll Alt L2 Alt L3 Ideal Alt S1 Alt S2 Alt S3
k1ternative MLE + M F MLE + I FAS Alternative FBIs Digestion + Digestion
+ RO MBR + RO Dryer + FBI Only
Liquids Alternatives TBL+ Scoring Summary Solids Alternatives TBL + Scoring Summary
28 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
9. RECOMMENDATIONS
Collection System
Long-term reliable collection and Gravity Sewers- Central San Pump Stations— An estimated
conveyance of wastewater to the replaces gravity sewers at a $33 million in pump station
treatment plant in Martinez is critical rate of less than 0.5 percent per improvements is recommended
for protecting public health and the year.The recommended annual between 2019 and 2023.The
environment.To maintain a high level replacement rate of gravity largest projects will rehabilitate
of service and continue to reduce sewers starts at 0.5 percent the Fairview, Maltby, Moraga,and
SSOs,the following projects and and ramps up to 1.2 percent Orinda Crossroads pump stations.
programs are recommended. within 10 years.At this rate,81 Similar improvements will be
Aging Infrastructure miles of sewer will be replaced required at other pump stations
in the next 10 years at a cost within the next 10 years.
Aging infrastructure projects include of approximately�280M,and
improvements to gravitysewers and
an additional 184 miles will be
pump stations to either replace or replaced in 10 to 20 ears at a cost
rehabilitate and extend the useful lives p y
of approximately$440M.Over
of assets.
the 20-year period,that 265 miles
represents nearly 18 percent of
the collection system.
PERIOD COST
0-5 Years $ t
5-10 Years •
10-20 Years $441 184
20-30 Years $724 281
80 30-50 Years $1,156 403
0 70 50-75 Years 575 206
60
E 50 75-100 Years $808 276 9—
v
+_J
(n 40
O
U 30
20
U 10
...... . .:....:
CO I-- O M C0 M N Lo 00 I-- O M C0 N Lo CO I-- O M C0 M N LSA 00 - I�
N N N M M M C 7 � Lo Lo Lo C0 C0 C0 I-_ r-_ r-_ 00 00 00 M M M M O O O
O O O O O O O O O O O O O O O O O O O O O O O O O O O = = = O
N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N N
Forecast Year
100-Year Recommended Pipeline Replacement Plan
COMPREHENSIVE WASTEWATER MASTER PLAN 29
Capacity
Legend MA
AR 2
CCCSC3 modeled sewers �
According to the hydraulic model,a
Preliminary capacity relief projects
Pleasant Hill-Grayson Creek Trunk Sewer Project 10-year event will cause surcharging
MAR 1
in 21 locations in the service area.This
_ means flow will exceed the S-foot
CCCSD Wastewater freeboard criteria in the manholes.
Treatment Plant
Twelve of these locations are predicted
PLH-4 to overflow the manholes and cause an
,`.,
SSO.
PLH-3 .,
PLH-2
One project(Pleasant Hill-Grayson
PLH-1 4. CreekTrunk Sewer is already under
WCK-1 ,� ) Y
; sem LAF-1 progress. For the remaining 20
LAF-2 LAF-5 locations,capacity relief projects were
developed, prioritized,and included
LAF-3 _
LAF-4 WCK-5 in the CIP. Before implementing some
of them,additional localized level
ORD-2
r�I
and flow monitoring specific to the
ORD-1 7 project locations will help confirm the
WCK-2
WC K-4
priority and scope of the relief project.
MSO R-2
MOR-1 WCK-3 IL Validating the collection system model
is an important ongoing effort to
NI
ensure the highest priority projects are
y
T
T
addressed first and to further confirm
V
[G
= the need for capacity relief projects.
0
x
f
Based on the growth projected in the
service area, no capacity relief projects
are required to handle increasing dry
O
V
weather flows. However,implementing
. some improvements and expanding
ID4
O
the collection system in North
Concord will be required to receive
flows from the Concord Community
p
0.
Reuse Pro jectdevelopment.Current
V
0 1 2 3 4 miles ratepayers would not need to fund
those improvements,and they are not
Date Saved:7012112016
included in the CIP.
Preliminary Capacity Relief Projects
30 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN I MAY 2017
COLLECTION SYSTEM CAPACITY RELIEF PROJECTS Regulatory
Project - The main regulatory driver for
ProjectID - Length
il� =W mw� collection system is the State Water
ORD-1 EI Camino Moraga Easement (Orinda) 1,612 Resources Control Board(SWRCB)
ORD-2 Moraga Way (Orinda) 1,156 issued general Water Discharge
MOR-1 Camino Pablo Diversion (Moraga) 1,442 Requirements(WDRs)for sanitary
MOR-2 Hodges Drive/Rimer Drive (Moraga) 475 sewer systems.Central San's
LAF-1 Deer Hill Road (Lafayette) 363 Sewer System Management Plan
LAF-2 Happy Valley Road (Lafayette) 1,185 (SSMP)summarizes Central San's
operations of its
and o
LAF-3 Moraga Road (Lafayette) 982 management p
collection system.The main goal of the
LAF-4 Pleasant Hill Road/Buchan Drive (Lafayette) 3,316 SSMP is reduce the occurrence of SSOs
LAF-5 Pleasant Hill Road/Springhill Road (Lafayette) 232 through preventative maintenance
WCK-1 Camino Verde/Geary Road (Walnut Creek) 2,276 and monitoring.Central San is in the
WCK-2 Tice Creek Drive (Walnut Creek) 403 process of updating its SSMP.
WCK-3 Tice Valley Blvd./Meadow Road/Lancaster Road (Walnut Creek) 4,154 Most of the SSOs in Central San's
WCK-4 Palmer Road (Walnut Creek) 1,026 service area are caused by root
WCK-5 Walnut Blvd. (Walnut Creek) 1,428 intrusion in 6-inch and 8-inch vitrified
PLH-1 Ardith/Kathleen Drive Diversion (Pleasant Hill) ----20 clay pipe.Using cleaning data,the
Pleasant Hill-Grayson Creek Trunk Sewer See project InfoMaster®capital planning software
y plans identified high cleaning frequency
PLH-2 Grayson Road/Pleasant Hill Road (Pleasant Hill) 2,882 locations in the service area.To show
PLH-3 Virginia Hills Drive (Martinez) 200 continuous improvement and to
PLH-4 2nd Avenue (Pacheco/Pleasant Hill) 1,837 reduce SSOs in the collection system,
MAR-1 Alhambra Avenue (Martinez) 1,528 these pipes will be a priority for future
MAR-2 Embarcadero Street Easement(Martinez) 987 sewer renovation projects.
Changes to Air Emissions requirements
Ile over the last five years from CARB,and
the EPA will affect the Central San's
air quality permits that are enforced
r,� q Y
��
-� — through the Bay Area Air Quality
271
Management District(BAAQMD)
t,-• Permit-to-Operate(PTO)(annual
L, permit)and the Title V permit(five-
year permit).Central San should plan
for increasingly stringent emissions
requirements and for emissions control
- equipment for stationary and mobile
combustion facilities and engines.
Sustainability
Collection System Crew Cleaning a Sewer
To ensure Central San can reliably
maintain a high level of service for
critical infrastructure,projects were
identified to rehabilitate existing
facilities based on the findings from
field condition assessments. In
COMPREHENSIVE WASTEWATER MASTER PLAN 31
addition to the rehabilitation projects, it is recommended an infiltration and inflow(1/1)identification pilot program
that Central San implement inspection programs that to assess the potential for reduction of 1/1 from renovation
utilize use high-tech inspection technologies to assess the projects. By monitoring flow before and after pipeline
condition of force mains and large diameter sewer pipes, rehabilitation,Central San can quantify the reduction in 1/1
which are traditionally difficult to assess.The inspection and can identify the most effective methods of 1/1 reduction
programs prioritize high risk facilities that have a high to be used in the future.
consequence of failure.These new inspections will update
the prioritization for replacementofforce Summary of Major Treatment Plant �t Recycled
p 9
mains and large diameter pipes and establish baseline data Water Recommendations
for condition that can be used in the InfoMaster® model for The following list summarizes the major recommended
tracking and financial planning as each pipeline ages and treatment plant improvement projects by phase(timing)
degrades. and by the applicable capital improvement drivers. Phase 1
Since the collection system has not experienced wet
projects are in the 0 to 5 year timeframe, Phase 2 projects are
weather capacity related overflows in many years,there
in the 5 to 10 year timeframe,and Phase 3 projects are in the
is no immediate regulatory driver to implement a private
10 to 20 year timeframe.Some projects span multiple phases
sewer lateral program. However,Central San may consider
and/or are driven by multiple key issues.
Q Headworks Screenings Upgrade PLC Systems Upgrades Phases 1 and 2
Q Pump&Blower Building Seismic UpgradeOOO40 Treatment Plant Urgent Repairs
O Switchgear Refurbishment-Phase 2 Applied Research&Innovations
Influent Pump Station Electrical Improvements Outfall Improvements-Phase 7 to 9
Q Mechanical and Concrete Renovations QQQ 0 TP Safety Enhancements-Phases 4 to 11
O Plant Control System 1/0 Replacement Annual Infrastructure Replacement Program
Q Y4 Equipment Replacement Recycled Water Distribution System Renovations
Q Fire Protection System-Phases 2 to 6 OO4D Plant Control System Network Upgrade Phases 1 and 2
Q Piping Renovation-Phase 9 OO4D Odor Control Upgrades-Phase 1 and 2
O O walnut Creek/Grayson Creek Levee Rehab O Wet Weather Flow Management
Q ►UV Disinfection Upgrades Primary Expansion Project
Q &Treatment Plant Security Improvements O2 Warehouse Seismic Upgrades
O1 0 Plant-Wide Instrumentation Upgrades O Laboratory Seismic Upgrades
O1 Innovative Bioenergy Demonstration 0 Miscellaneous Seismic Upgrades
O1 Solids Conditioning Building Roof Replacement Clearwell Improvements
O1
111DO UV Hydraulic Improvements QQ 00 Secondary Treatment Hydraulic Improvements
O1 Condition Assessment of Buried Pipelines0 3Q� WWTP SCADA Replacement
O Plant Operations&Lab Data ImprovementsO 3001 Solids Handling Facility Improvements-Phase 2
O1 4D 4D Filter Plant Improvements3Q4D Solids Handling Facility Improvements-Phase 3
Ol O2 4D 404DAeration and Energy Upgrades Tunnel Improvements
Solids Handling Facility Improvements Secondary Clarifier Improvements
Ol O2 Plant Operations Building Seismic Upgrades DAFT Improvements
Ol O2 � Surcharge Soil Pile Relocation
Ol O2
Aging Infrastructure O1 Phase 1(0 to 5 years)
Nutrient Removal (BACWA Level 1)
Ol O2 UV Disinfection Replacement Capacity O Phase 2(5 to 10 years)
Ol O2 Treatment Plant SCADA Improvements Regulatory 30 Phase 3(10 to 20
Sustainability years)
Treatment Plant Projects and Their Drivers
32 1 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN MAY 2017
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COMPREHENSIVE WASTEWATER MASTER PLAN 33
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34 TECHNICAL EXECUTIVE SUMMARY
CENTRAL SAN MAY 2017
10. RECOMMENDED CAPITAL IMPROVEMENT PLAN
The Capital Improvement Plan(CIP)encompasses a $1.8 Billion
(2016 dollars)20-year improvement program. 1% 3%
The Master Plan's recommended projects were categorized into
four programs:
1. Treatment Plant($856 Million)
2. Collection System($819 Million)
3. Recycled Water($26 Million)
4. General Improvements($54 Million) 47%
A fifth category"Future Unfunded"includes other identified
projects that are not currently included in the CIP.These"future
unfunded"projects amount to an additional $920 million beyond
the$1.8 Billion CIP,of which approximately$501 million may be
within the next 20 years. Some of these projects were identified
to meet potential uncertain future regulations and other projects
expected to be cost-neutral to Central San,such as the future Treatment Plant
wholesale of recycled water. Collection System
Recycled Water
General Improvements
Total 20-Year ClP Breakdown,by Program
$120,000,000
$100,000,000
$80,000,000
$60,000,000
■
$40,000,000 loom
$20,000,000
M
$0
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037
Treatment Plant Collection System Recycled Water General Improvements
Total 20-Year ClP Annual Cash Flow din 2016 Dollars)
COMPREHENSIVE WASTEWATER MASTER PLAN 35
11. EMBRACING INNOVATION
The CMWP has identified proven
technologies that can be utilized
to meet future nutrient limits, � �
wholesale recycled water needs,and
technologies for solids handling and -
resource recovery. technologies
Ya. - r
4
are essential for ensuring Central San - 10 -
has a flexible plan in place if these -
systems need to be replaced. However, r .
the industry is rapidly changing and
emerging and innovative technologies -
may offer improved life cycle costs,
�1�1l ��y`� ���
increased energy efficiency,and/
or reduced footprint requirements.
r r;
Central San continues to invest in
applied research to continue to find the
best available technologies.
a
Central San encourages innovation by �.
exploring emerging and embryonic -
r�
technologies that may change the A oil
way wastewater is treated globally.
Central San is actively seeking out
Central San Lab Technician
opportunities to partner with other
companies,research and academic
institutions,and other public agencies '
to explore promising solutions to
liquids treatment,solids handling,
Central San, part of a consortium led by the
and energy and resource recovery. Water Environment& Reuse Foundation,was
Although man of these innovative selected by the Department of Energy(DOE)to
g Y
technologies are not considered tried receive a highly sought after federal grant for an
and true in the industry,Central San
applied research project to test a breakthrough,
is invested in being at the forefront of emerging bioenergy technology(to be hosted
innovation. By embracing innovation,
at Central San).The proposed technology,
Central San may be able to achieve hydrothermal processing,is aimed at converting
y
meaningful reduction in energy wastewater solids into clean,renewable fuels
demands maximize recover of r� such as biocrude and biomethane gas.The
Y �
valuable resourcesand improve project is scheduled to begin in Summer 2017.
, s
lifecycle costs while still maintaining a
high degree of reliable service. Biocrude Oil
36 1 TECHNICAL EXECUTIVE SUMMARY