HomeMy WebLinkAboutSchaaf & Wheeler Sewer Evaluation
City of Fontana
Sanitary Sewer Pump Station Evaluation
Schaaf & Wheeler
Consulting Civil Engineers
August 9, 2011
City of Fontana - i - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table of Contents
Overview...............................................................................................................1
Pump Station Evaluation.......................................................................................3
Pump Station Inflows and Capacities.................................................................3
Pump Application and Control Strategy.............................................................5
Pump Station Reliability.....................................................................................8
Force Main Evaluation.....................................................................................10
Flow Measurement and Monitoring..................................................................12
Electrical Equipment and Motor Control Center Assessment ..........................13
Emergency/Backup Power Generation............................................................14
Communication and Monitoring .......................................................................15
Structural and Seismic Assessments...............................................................16
Miscellaneous Site Assessments.....................................................................19
Immediate Recommended Improvements .......................................................19
Cost Estimates....................................................................................................19
List of Figures
Figure 1: Pump Station Location Map...................................................................2
List of Tables
Table 1: Pump Station Firm Capacities and Inflows..............................................5
Table 2: Pump Station Reliability Summary..........................................................9
Table 3: Estimated Time to Overflow..................................................................10
Table 4: Force Main Evaluation Summary..........................................................11
Table 5: Emergency/Backup Power Generation Summary.................................15
Table 6: Existing Station Alarms and Communication .......................................16
Table 7: Fontana Pump Stations Structural Inspection Summary Table.............18
Table 8: Immediate Improvement Cost Summary...............................................19
Table 9: Pump Station Replacement Cost and Recommended Rehabilitation
Date ..............................................................................................................21
Appendices
A – Individual Pump Station Reports
A1 – Tamarind A4 - Locust
A2 – Southridge A5 - Industry
A3 – Barbee
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Sanitary Sewer Pump Station Eval. August 9, 2011
Overview
The City of Fontana (City) engaged Schaaf & Wheeler, Consulting Civil
Engineers to evaluate five (5) sanitary sewer pump stations owned and operated
by the City. Each station was visited and evaluated based on the following items:
• Pumping capacity
• Efficiency and reliability of pump application and control strategy
• Pump station reliability
• Condition and reliability of electrical equipment and motor control centers
• Emergency/backup power generation
• SCADA control and monitoring
• Flow monitoring program and equipment
• Compliance with state and federal codes and regulations
• Structural integrity and seismic vulnerability
• Force main age and visible condition
The location of each pump station evaluated is shown in Figure 1. This report
describes the criteria used to evaluate each station and summarizes the pump
station evaluations. Detailed individual pump station reports are included in
Appendix A.
A rehabilitation cost and recommended schedule has been developed for each
pump station. Rehabilitation costs range from $320,000 to $700,000, and the
total cost to rehabilitate all five pump stations is approximately $2,440,000.
Recommended immediate improvements have been identified for each pump
station. The total estimated cost to implement the immediate improvements at all
five pump stations is $453,000.
Schaaf & Wheeler’s subconsultant Fehr Engineering, Inc. evaluated the power
and electrical systems of each pump station, and Biggs Cardosa Associates, Inc.
evaluated the structural condition and performed seismic assessments.
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Figure 1: Pump Station Location Map
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Pump Station Evaluation
The following sections describe the pump station assessment performed for each
of the five pump stations. Analysis of the current condition of each station is
limited to visual inspection, pump drawdown tests, flow monitoring data, and
information provided by the City. Pump station site visits and drawdown tests
were performed on May 17, 2011. Information regarding the existing pumping
logic, known issues, and desired improvements were obtained from the City’s
operations and maintenance staff during the site visits and follow-up
correspondence.
Anticipated service life of pump station equipment varies greatly based on
several factors. It may be necessary to replace some equipment earlier than
noted, and some may last longer than expected.
Pump Station Inflows and Capacities
Sanitary sewer pump stations are typically designed to have a firm capacity
equal to or greater than the peak wet weather inflow (PWWF) to the station. Firm
capacity is defined as the capacity of the pump station with the largest pump out
of service. PWWF rates represent the maximum contribution of a given pump
station’s tributary service area including groundwater infiltration and direct
stormwater inflow. Peak dry weather inflow (PDWF) rates represent the
maximum contribution excluding groundwater infiltration and stormwater inflow.
Historic sewer flow records or trends, master planning documents, and sewer
modeling reports are not available for the City’s sewer system. To better
determine actual sewer flow rates, the City initiated a short-duration flow
monitoring program at the inlet pipes to each of the five pump stations. The
flows were monitored by ADS Environmental Services during the week of April
23 through May 4, 2011. The results are summarized in the Flow Verification
Report for the City of Fontana Sanitary Sewer Pump Station Analysis Project
dated May 12, 2011, which was provided by the City for reference. The report
includes graphical and tabular data of the inflow rates recorded during the
monitoring period.
Rainfall data from the California Data Exchange Center shows that the two rain
gauges nearest to Fontana, the San Bernardino County Yard gauge and the Day
Canyon gauge (Rancho Cucamonga) received no or only trace amounts of rain
during the study period and two weeks prior. Therefore, the flow data is
considered to represent dry weather inflow rates. The peak value recorded
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during the monitoring period was taken as the PDWF for each station.
In the absence of data representing the PWWF, a wet weather peaking factor
was applied to the PDWF. The City of Fontana does not have established wet
weather peaking factors; therefore, Sanitary Sewer Master Plans for neighboring
cities were reviewed to find a typical peaking factor for the area. The City of
Riverside uses a peaking factor of 1.22 and the City of Ontario uses 1.34. To be
conservative, a peaking factor of 1.34 was used for this study.
The data set used to determine PDWF for each station is limited to a one week
period, during dry weather. Sewer flow rates can be highly variable on a weekly,
monthly, and seasonal basis; therefore, the accuracy of the flow rates used for
this report should be considered crude at best. Additionally, the inflow rate for
the Industry pump station could be greatly affected by the industrial processes
that occur within the service area. If there are processes that do not occur on a
weekly basis, and they did not occur during the monitoring period, then the peak
inflow rate at the pump station could be significantly larger than what was used
for this report.
Prior to performing pump station rehabilitations we recommend performing a
more comprehensive and longer duration flow monitoring program that
encompasses both the wet and dry season. The larger data set will allow the
City to more accurately determine the appropriate flow peaking factors and in-
turn more accurately define the required pump station capacities.
As the pump station inflow rates are better defined, the improvement
requirements within this report may be affected.
The firm capacity was determined by performing drawdown tests on all five
stations. The drawdown tests were performed by recording the time it takes the
pump station, without the largest pump, to draw down the wetwell a measured
distance. The average inflow rate is determined by recording the time it takes
the station to fill up over a measured distance in the wetwell. The resulting
calculated pump discharge rate is approximate due to the difficulty of getting
accurate volume measurements, especially on stations where the intake pipe is
below the operating level of the station. A comparison of the pump station firm
capacities and inflows is shown in Table 1.
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Table 1: Pump Station Firm Capacities and Inflows
Pump Station Total # of Pumps
Firm
Pumping
Capacity
(GPM)
Existing
PDWF
(GPM)
Existing
PWWF
(GPM)
Tamarind 2 1183 485 650
Southridge 3 790 714 957
Barbee 2 47 66 88
Locust 2 70 120 161
Industry 3 383 352 472
Only the Tamarind pump station has sufficient capacity for the existing PWWF.
The Barbee and Locust pump stations are significantly undersized and do not
have sufficient capacity for the PWWF or the PDWF. The downstream sewer
systems were not analyzed as part of this analysis. Prior to upsizing the pump
stations, the capacity of the downstream system should be analyzed to confirm
that it has sufficient capacity to convey the proposed peak discharges.
Pump Application and Control Strategy
The efficiency and reliability of the pump application and control strategy for each
station was evaluated based on the following criteria:
Pump Type:
• Efficiency of existing pumps in relation to similar pumps that are currently
available
• Issues encountered with current pumps, based on O&M staff input
Variable Frequency Drives:
• Can the station be more effectively and efficiently operated with the use of
a Variable Frequency Drive (VFD)
Pump Size and Number of Pumps:
• Comparison of firm capacity to the PWWF
• Can more efficient and effective pumping be achieved with more or less
pumps
Pump Station Configuration:
• Does the size of the current wetwell allow for proper pump cycling
• Potential pump operation issues with station configuration
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Control Strategy:
• Efficiency of existing control strategy
• Does control strategy have adequate redundancy (secondary pump
controls)
Recommended modifications or upgrades to the pumps, pump configurations,
and control strategies are discussed in the individual pump station reports within
Appendix A.
Pump Station Controls
To meet the reliability requirements discussed in the following section of this
report, each pump station shall have a set of fully redundant pump controls. We
recommend a combination of automatic and mechanical devices that start/stop
the pumps according to the water level in the station’s wet-well. Automatic
controls would ideally be supplied with an uninterruptible power source i.e. a
battery backup with enough capacity to control the system until the permanent
backup generator can start and power the station (where applicable). The
uninterruptible power source should also be capable of powering the
communications system so that a power failure alarm can be sent when
necessary. The mechanical backup should send a high level alarm and provide
independent mechanical control of the station. A typical automatic control is a
PLC with a transmitter/receiver which measures levels on a continuous basis. A
typical mechanical system is a series of relays and float switches; a high water
float switch to start all pumps and to send a high water alarm, and a second float
switch to shut pumps off at the indicated low water level and send a low water
alarm.
The five pump stations assessed are not currently capable of operating
automatically in the event of a pump controller (PLC) failure. To remedy this, a
secondary controller should be installed and should be independent of the
primary controller. It is recommended that this controller be a basic pump control
circuit that starts all available station pumps when the high level float is tripped
and stops all pump when the low level float is tripped. Alternatively, more than
one high level float switch can be used to start each individual pump separately.
Variable Frequency Drives
All of the stations assessed currently operate as constant speed (C/S) pumps.
The Industry lift station currently has variable frequency drives (VFD); however,
they currently operate at a constant speed. When the station rehabilitations are
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Sanitary Sewer Pump Station Eval. August 9, 2011
being designed, the design engineer may consider using variable speed (V/S)
pumps. Variable speed pumps have advantages and drawbacks, when
compared to constant speed pumps that need to be considered on a station-by-
station basis during the design process. The benefits may include:
• Shorter sewage residence time in the wetwell
o Reduction in solids deposition
o Reduction in odor and corrosive gas
• Reduction of required wetwell size (may not be a benefit if existing wetwell
is adequately sized for C/S pumping)
• Fewer pumps required to meet a variety of flows
• Reduced pumping energy (with appropriate application)
The drawbacks include:
• Short time to overflow in the event of a pump station failure due to
decreased wetwell storage
• Larger pumps required to meet peak flow
• Longer pump run times (continuously in many cases)
• Lack of pump redundancy
• Increased cost of construction
• Increased system complexity
• Increased operation and maintenance
When considering V/S pumps, it is prudent to examine the station to ensure that
the perceived benefits of V/S operation will provide a benefit to the station. First,
each station’s location should be investigated with respect to available land as
well as proximity to odor sensitive neighbors. The stations evaluated herein have
existing wetwells that are large enough for C/S operation with acceptable pump
cycle times. Additionally, City personnel did not express concerns regarding
odor (outside of pump station limits) at any of the evaluated stations.
Next, the design engineer should determine the required number of pumps for
operation and reliability. While V/S pumping may allow a reduced number of
pumps needed, typically, each pump is larger (and more expensive) than the
pumps used for C/S pumping. Also, for V/S pumping, each pump must be
equipped with a Variable Frequency Drive (VFD). The cost to install VFDs and
the associated electrical equipment (including redundant starters for C/S VFD
bypass) can significantly reduce or eliminate the savings found by installing fewer
pumps.
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When looking at potential benefits of V/S pumps, it is important to determine if
decreasing the required pumping energy is possible. There are two main factors
that affect this; first, to maintain cleansing velocities the pump speed can only be
reduced to a point where force main velocities remain above 2 ft/s. Second, due
to the affinity laws that govern V/S pump operation, pumps can maintain
maximum efficiency for a variety of flows only if the head seen by the pump is
dominated by friction losses in the force main. That is, if the pumping head is
mostly static (short force mains), pump efficiencies can not be maintained and
energy savings are diminished or eliminated.
Lastly, consideration should be given to how V/S pumping will affect the
operation and maintenance staff. Including V/S pumps in a station increases the
operational complexity, forcing O&M personnel to service, maintain and operate
an additional piece of complicated equipment. If City staff can not
maintain/service the VFDs, a third party servicing company will need to be
contracted with. Additionally, it is Schaaf & Wheeler’s experience that when
VFDs fail; operators generally bypass the unit entirely and operate the station as
a C/S station.
In general, the benefits of V/S pumping can only be determined by conducting
detailed analysis of specific pumping systems on a station by station basis.
Based on the preliminary review of the existing pump station, Schaaf & Wheeler
does not believe that significant savings and benefits can be realized with V/S
pumping at the five pump stations evaluated within this report. A detailed
analysis comparing V/S and C/S operation should be performed by the design
engineer during each station rehabilitation/reconstruction project.
Pump Station Reliability
Several cities throughout California have recently received cease and desist
orders (CDO) from the Environmental Protection Agency (EPA) and the Regional
Water Quality Control Board (RWQCB) requiring them to evaluate and certify the
reliability of their sanitary sewer pump stations. The requirements are intended
to reduce the potential for sanitary sewer overflows (SSOs). Each pump station
was evaluated on the following requirements, which were developed based on
the requirements set forth by the EPA and RWQCB.
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1. Each station and force main should be capable of handling the PWWF
without overflow.
a. A high level gravity bypass pipe may satisfy all requirements
herein if it is capable of conveying the PWWF without overflow.
2. Each pump station should have an automatic alarm and
communication system that notifies the City of an electrical or
mechanical failure.
3. Each station should have backup or redundant equipment (pumps and
power supply).
a. Each station shall be capable of handling the PWWF with the
largest pump out of service.
b. Each station shall have a permanent backup generator.
i. If there is not adequate room for a permanent backup
generator, or if the City decides not to install permanent
backup generators, the City shall have a plan in place to
ensure the pump stations continue operation in the event of
a citywide power outage (respond to alarm with portable
generator before overflow).
4. Pump station force mains shall be capable of conveying the PWWF
while maintaining a flow velocity between 2 and 10 feet per second
under normal operating conditions.
a. The City shall have a plan for bypass pumping at each station if
necessary. Methods of bypass pumping may require the
addition of a bypass pumping connection to the force main and
the use of portable pumps.
A summary of the pump station reliability requirements are shown in Table 2,
additional information is included within the individual pump station reports in
Appendix A.
Table 2: Pump Station Reliability Summary
Pump Station
Increase Firm
Pumping Capacity to
Meet PWWF
Add Bypass
Pumping
Connection
Modify
Secondary
Pump
Controls
Modify
Communication
System
Tamarind XX
Southridge XXXX
Barbee XXXX
Locust XXXX
Industry XXX
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Time to Overflow
The time to overflow for a pump station gives the City an idea of the amount of
time they have to respond to a pump station failure before an overflow occurs. It
was assumed that no pumps were running, and a constant inflow rate equal to
the PDWF and PWWF. The City provided GIS data, record drawings, and USGS
topography data was used for manhole rim and invert, pipe length and pipe
diameter data. The storage volume in the system between the lowest manhole
rim elevations and the high level float alarm elevation was determined by
calculating the volume of the manholes and pipes between these elevations.
The total storage volume was then divided by the PDWF and PWWF rates to
calculate the time to overflow. A summary of the estimated time to overflow is
shown in Table 3.
Table 3: Estimated Time to Overflow
Pump Station PDWF Time to Overflow
(hrs)
PWWF Time to Overflow
(hrs)
Tamarind 4.2 3.2
Southridge 1.9 1.4
Barbee 2.4 1.8
Locust 3.0 2.2
Industry 1.1 0.8
Force Main Evaluation
The pump station force mains were evaluated on their ability to convey the
PWWF while maintaining a flow velocity between 2 and 10 ft/s during normal
operation. Force main design standards recommend maintaining a minimum
flow velocity of 2 ft/s under normal operation to prevent solids from settling.
The maximum flow velocity of 10 ft/s is a recommendation developed to minimize
friction head loss and surge pressures within the force main.
A summary of the force main evaluation is shown in Table 4. The force main
sizes were obtained from the City’s record drawings and GIS data.
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Table 4: Force Main Evaluation Summary
Pump
Station
Force
Main
Diameter
(inches)
Force
Main
Material
Force
Main
Length
(ft)
Existing
PWWF
(GPM)
Station
Firm
Capacity
(GPM)
Velocity1
(ft/s)
Date
Constructed
Age
(Years)
Tamarind 12
Ductile
Iron 2240 650 1183 3.4 1994 16
Southridge 10
Ductile
Iron 2600 957 790 3.9 1983 27
Barbee 4 – 8
PVC/
Steel/
VCP 1600 88 47 2.3 – 0.6 1971 39
Locust 4 PVC 1085 161 70 4.1 1977 33
Industry 8 PVC 2460 472 383 3.0 1988 22
1. The flow velocity was calculated by using the larger of the PWWF and the firm capacity.
The City’s force mains were constructed between 16 to 39 years ago. Some of
the piping and valves within the wetwells have minor corrosion; however, it does
not appear to be significant enough to threaten the reliability of the equipment.
Recommendations for improvements to the existing force mains are included
within the individual pump station reports in Appendix A.
We recommend performing detailed force main inspections during the next pump
station rehabilitations, and replacing or rehabilitating the force mains as
necessary. The most wide-spread inspection method for force mains is Closed-
Circuit Television (CCTV). The CCTV inspection technique requires taking the
force main out of service and inserting a remotely operated video camera into the
pipe. The camera is then maneuvered throughout the pipe and visible breaks,
root intrusion, sags and corrosion are noted. During station rehabilitation CCTV
inspection of the force main should be performed as a minimum. If defects/issues
are noted through CCTV inspection, additional inspection may be necessary to
determine the urgency of the needed repair. The Environmental Protection
Agency (EPA) report titled “Report on Condition Assessment Technology of
Wastewater Collection Systems”, published in August, 2010 provides detailed
descriptions of currently available inspection methods as well as common
failures/defects for each of the different pipe materials.
Bypass Pumping Connection
The City shall have a plan to perform bypass pumping at each pump station, in
the event of a pump station failure. Bypass pumping may require the addition of
a bypass pumping connection unless the discharge manhole is relatively close
and a flexible hose can easily be routed from the wetwell or upstream manhole to
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the discharge manhole without causing access issues with roads or sidewalks. A
bypass pumping connection will enable the use of temporary pumps should the
station have a fire or failure of the panel and electrical system. A bypass
pumping connection is also useful during routine maintenance so the wetwell can
be completely drained. The pumping connection shall include an isolation valve
so that work can be performed on the force main and valves within the pump
station. We recommend the City have a plan in place to perform bypass
pumping in the event of a pump station failure. This may require purchasing
portable pumps or obtaining a rental agreement to provide portable pumps on an
as needed basis.
Flow Measurement and Monitoring
Flow measurement at sanitary sewer pump stations can aid in determining
sewershed generation rates, can be used to calculate the volume of sewage sent
to the wastewater treatment plant, to calibrate the sanitary sewer model, and to
monitor the pumping rate of the pumps to detect clogging or other issues. None
of the stations have existing flow meters.
There are several methods of flow measurement within force mains; however,
there are only a few that are recommended for wastewater applications. We
recommend using the following devices for wastewater force mains:
Ultrasonic Flow Meter
An ultrasonic flow meter can be attached to the outside of a force main. A dopler
signal is sent, received, and measured by the device, which is then correlated to
flow rate based on the type, thickness, and size of the force main. Any corrosion
or sediment buildup within the force main will
significantly decrease the accuracy of the flow
meter. The advantages of an ultrasonic flow
meter are that they can typically be installed
without taking the station off-line, and they are
cheaper than other in-line measurement devices.
The accuracy of ultrasonic flow meters is typically
between 2% and 5% when properly located on a
pipe of a known material and thickness.
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Electromagnetic Flow Meter
Electromagnetic flow meters (mag meter) are ideal for wastewater applications
and can be highly accurate if properly used. Mag meters
do not have any moving parts, and do not create a
significant head loss. The accuracy of mag meters can
be within 0.5% of the flow rate, if properly located. Most
manufacturers recommend placing mag meters at least
5 pipe diameters downstream and 2 pipe diameters
upstream of pipe fittings. The installation of a mag meter
typically requires the station to be taken out of service,
and it may require a new valve vault if there isn’t
sufficient room with the current pipe configuration.
It is also useful to have pressure gages on the force mains of larger pump
stations. The pressure readings can be used to calculate the flow rate and can
also be used to determine the operating head of the pumps. The use of pressure
gages in conjunction with flow meters can also be used to determine the head
loss -within the force main. Some of the existing force mains have pressure
gages; however, several of them are inoperable. The pressure gages should be
replaced/installed during the next pump station rehabilitation.
If flow metering is desired by the City, we recommend placing flow meters at the
Tamarind, Industry, and Southridge pump stations as discussed in the individual
pump station reports. The Barbee and Locust pump stations have relatively low
inflows; therefore, flow monitoring at these stations may not be necessary unless
the sewershed generation rates and discharge rate of the lift station are desired.
Electrical Equipment and Motor Control Center Assessment
In general, the five pump stations evaluated are well maintained and appear to
be fully operational per the original design, with the exception of the Southridge
station that had one pump out of order. Observed Electrical Code violations and
recommended improvements are mentioned within in the individual pump station
reports in Appendix A.
Although the general conditions of the stations observed were good and
maintenance of the stations appeared to be thorough, there are components
which will eventually fail. Consideration should be given to standardization upon
replacement of failed equipment. Furthermore, there are numerous conditions
which don’t meet requirements for reliable operation of the stations and these
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conditions should have priority to insure safe operation of the stations.
Motor Starters
The existing pump starters are well maintained and serviceable. As with all
equipment, starters will eventually fail and require replacement. We recommend
that a replacement plan be in place so that when replacement is required (upon
equipment failure), changes may be made quickly.
The Barbee, Locust, Southridge, and Tamarind lift stations use electronic
reduced voltage starters as starting aids and each of these starters are of the
same manufacture and type. Maintenance personnel report to be satisfied with
this equipment so we would suggest that no change be made at this time. The
Industry Lift Station uses Toshiba variable frequency drives to control the motors.
The drives are used at a constant speed which defeats the purpose of the drive.
The drive could be replaced by an electronic reduced voltage starter to achieve
the same goal. We suggest either using the drives as variable speed controls or
replace the drives with less expensive starters during the next pump station
improvement. A trend to equip stations with components which are
interchangeable is suggested to increase reliability. It appears that the City has
made efforts to achieve station compatibility and this effort should be continued.
Emergency/Backup Power Generation
The City currently has a generator assigned to each station, either permanently
installed or a dedicated portable. The detailed individual pump station reports
address possible areas of concern but for practical purposes the City is capable
of operating all five stations with standby emergency backup power. An added
reliability component at the locations where a permanent generator is installed
would be to add a means to quickly connect a portable generator in the event of
permanent generator failure. This could be accomplished using a generator plug
tied into the main power bus with mechanical interlocks to comply with utility
requirements.
The required run time for backup generators without refueling depends on the
City’s ability to refill the fuel tanks during a large, extended power outage. In our
experience with designing backup generators for similar agencies, having
sufficient fuel supply to run the generator for 48-hours at full load allows the
operating agency enough time to refuel the generator. The City may choose to
increase or decrease the fuel storage requirement based on the location of the
generator and the availability of fuel trucks during extended power outages.
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Table 5: Emergency/Backup Power Generation Summary
Pump Station
Has Backup
Generator
Onsite
Has Dedicated
Portable
Generator
Offsite
Has Receptacle
for Portable
Generator
Connection
Add Receptacle
for Portable
Generator
Connection
Tamarind X X
Southridge X X
Barbee X X
Locust X X
Industry X X
Communication and Monitoring
A Supervisory control and data acquisition (SCADA) system is typically used to
collect and send alarm data, and a RTU (Remote Terminal Unit) or a telephone
connection is typically used to convey the information. Information and control
signals are sent and received between supervisory locations and controlled
points on a continuous basis.
As mentioned in the pump station reliability section, from a reliability standpoint,
each pump station shall have an automatic alarm and communication system
that coordinates with the City’s on-call staff. The system shall have a backup
power source to ensure continuous operation in the event of a power failure. At
a minimum, sanitary sewer pump stations shall have the following alarms:
• Pump Failure (for each pump) which sends a SCADA signal notifying
operators of the failure.
• Power Failure notifying operators that the primary power has failed and
that the station has transferred to a secondary source of power either
manually or automatically.
• High water in the wetwell send a SCADA signal and starts all available
pumping.
• Low water in the wetwell sends as SCADA signal and stops all pumping.
• Communications Failure
Each of the City’s five pump stations that were assessed is equipped with a
telephone communications system with one station having a secondary RTU
system in place. If there are failures or power is interrupted, a communication
failure alarm is reported to the supervisory location.
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The existing communications system currently has the capability to send alarm
signals to a central location; however, it is not possible to remotely control the
station. Remotely controlling wastewater pump stations is an added operational
benefit; however, it is not necessary from a reliability standpoint. If the pump
stations are upgraded to meet the previously mentioned reliability requirements,
then the station will automatically turn on and off all available pumps as
necessary, even with the failure of major pump station equipment. Furthermore,
the cost to upgrade the existing communications to a remotely controllable
system is significant. A summary of the current alarm and communication data is
shown in Table 6.
In addition to the mentioned requirements, we recommend the City continue to
standardize the pump station equipment. With a standardized system the City
would be able to keep a minimum replacement parts inventory on hand for
emergency repairs. Using a standard set-up, components could be cannibalized
from any pump station under dire circumstances. Furthermore, a standard
system is the easiest to maintain since each station is essentially the same.
Table 6: Existing Station Alarms and Communication
Tamarind Southridge Barbee Locust Industry
Alarm
Com. Fail X
Power Fail XXXXX
Site Entry
Panel Entry
Battery Low
Pump Fail XXX X
High Level XXXXX
Low Level X X X X
Drywell Flooding X X
Generator Fail
Structural and Seismic Assessments
The structural/seismic assessment portion of this project involved a visual survey
of the pump station facilities focusing on the general structural condition of the
pump stations and their components and the presence of any conditions which
would pose a potential hazard in the event of an earthquake. When available, the
as-built structural drawings were also reviewed. This assessment utilized a
probabilistic approach (as opposed to deterministic) to identify structural
deficiencies and seismic hazards. Our assessments of the pump stations were
based on our experience in the design and anchorage of similar structures and
equipment, our knowledge of the governing California Building Code, and our
City of Fontana - 17 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
understanding of what is generally necessary to adequately and safely anchor
equipment in a seismically active area.
The assessment of the general structural condition of each pump station included
consideration of the following items:
1. Overall condition of the pump station concrete structure including
cracking, deterioration, or spalling of the concrete.
2. Overall condition of associated buildings and other structures.
3. Corrosion of metal components of the structure, piping and ductwork,
exterior panels and cabinets, and equipment bases, stands, or base
plates.
4. Obvious settlement of the structure or the dirt or pavement around the
structure.
5. Condition of the hatches, ladders, stairs, and platforms.
6. Condition of non-shrink grout at base plates or other locations.
7. Presence of roots growing into the wetwells through joints in the structure.
8. Deterioration of any wood components.
9. Compliance with the California Building Code and all applicable
referenced design codes.
The assessment of the pump stations and their components for seismic hazards
included consideration of the following items:
1. Anchorage of pumps and motors, electrical/control panels and cabinets,
emergency generators, fuel tanks, antenna poles, and other equipment.
2. Lateral bracing of suspended equipment, discharge piping, ductwork,
electrical conduit, and other miscellaneous piping.
The pump stations are in good overall condition. Most stations only require
future monitoring of certain items and only minor maintenance. However, a
couple stations have structural issues that should be mitigated in the near future.
Minor cracking was observed in some of the concrete, but this is common and
only major cracks require mitigation and are specified as such in the report. A
summary table listing the major items along with maintenance and monitoring
items is below:
City of Fontana - 18 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 7: Fontana Pump Stations Structural Inspection Summary Table
Station Major Items Maintenance & Monitoring
Tamarind • None • Crack in retaining wall mortar cap
• Wetwell frame rust
• Bent support hook at wetwell
• Concrete settlement
• Verify proper electrical equipment
anchorage
Southridge • Perimeter block
wall strength
deficiency under
seismic loading
• Unanchored Hazardous Waste
storage cabinet
• Deterioration of ridge and edge
beam at outer ends
• Water damaged drywall &
framing near door
• Verify proper electrical equipment
anchorage
Industry • Roof framing was
removed for crane
leaving roof
unsupported
• Top plate of
bearing wall near
crane cut almost
completely
through
• Perimeter wall damage due to
neighboring truck impacts
• Unanchored flammable item
storage cabinet
• Deterioration at ends of support
beams
• Small hole in exterior wall
• Verify proper electrical equipment
anchorage
• Possibly lacking typical seismic
resisting elements
• Stair support steel rust
• Ladder grout pad deterioration
• Minor drywell cracking
Locust • None • Cracking around inlet manhole
frame
Barbee • None • Tree root intrusion into inlet
manhole
• Pipes in valve vault not properly
supported
• Sidewalk settlement
See the individual report for each station in Appendix A for further information
City of Fontana - 19 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Miscellaneous Site Assessments
The overall condition, access, safety, and flood hazard of each pump station was
assessed. Identified deficiencies and recommended improvements are
mentioned within the individual pump station reports. None of the pump station
sites are located within the 100-year FEMA floodplain.
Immediate Recommended Improvements
Several recommended immediate improvements have been identified for each
pump station, which are identified in the individual pump station reports. The
immediate improvements include the reliability deficiencies and other minor items
that will help improve the overall function and reliability of the pump station.
To help prevent sanitary sewer overflows, we recommend implementing the
immediate improvements as soon as possible. A summary of the estimated cost
of immediate improvements is shown in Table 8. The priority ranking is based on
the risk for sanitary sewer overflows and the inflow rate at each station.
Table 8: Immediate Improvement Cost Summary
Pump Station Total w/ Contingency
Priority
Ranking
Tamarind $11,000 5
Southridge $143,000 3
Barbee $82,000 1
Locust $90,000 2
Industry $127,000 4
TOTAL $453,000
Cost Estimates
The rehabilitation cost estimates for each station have been created to provide
expected pump station replacement costs to be used for a long term budgetary
analysis, and to assist in the development of an on-going pump station
rehabilitation program.
Pumping facilities rely heavily on mechanical and electrical equipment that wear
out. On average, pumping equipment can be expected to last anywhere from 20
to 30 years with proper maintenance. Structural facilities should last much
longer, at least 50 years, although metal, wood, and even concrete surfaces all
require regular care. Therefore, we recommend using a 25-year replacement
schedule for all equipment within the pump station and rehabilitating other items
such as pump station roofs and concrete structures. The existing structures are
City of Fontana - 20 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
in good shape; therefore, we assumed that the structures do not have to be
replaced during the next pump station rehabilitation.
The recommended rehabilitation priority is based on the age, overall condition,
and inflow rate of the pump stations. The rehabilitation dates were spaced out to
accommodate for equal annual investments for the overall pump station
rehabilitation program. We recommend that City maintenance crews monitor the
condition of the facilities and replace items as necessary, as some of the pump
station equipment is already past the recommended 25-year replacement date.
It was assumed that the immediate improvements (reliability deficiencies) will be
taken care of prior to pump station rehabilitation. The replacement items within
the immediate improvement are also included in the rehabilitation estimates.
It is important to keep in mind that numerous uncertainties could alter the future
costs and replacement methods. This study projects costs into the future, when
available technology and relevant regulations are unknown at this time. The
rehabilitation costs may increase if electrical service needs to be upgraded, if
additional easements are needed, or if the station needs to be relocated due to
limited space.
The estimates are based on similar construction projects, published unit costs
(prevailing wage rates), and cost index values. All costs include materials and
labor and the cost index used at the time of this estimate is the June 2011 Los
Angeles Construction Cost Index (index value = 10051.30). An additional 55% is
added to the estimates of probable construction costs to account for construction
contingency (30%), engineering design (10%), project administration,
construction management, permitting and other soft costs (15%). Detailed
rehabilitation cost estimates are included within each individual pump station
report, and a summary of the total costs along with the recommended
rehabilitation date is shown in Table 9.
Annual maintenance costs are not included within this analysis. The City is in a
better position to evaluate the efficacy of their ongoing maintenance operations,
identify the need for expansion or reduction of their operation and maintenance
program, and calculate the associated increase or decrease in cost as
appropriate.
City of Fontana - 21 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 9: Pump Station Replacement Cost and Recommended Rehabilitation Date
Pump
Station
Current
Replacement
Cost w/
Contingency
Rehabilitation
Priority
Ranking
Current
Age of
Station
(Years)
Recommended
Rehabilitation
Date
Station Age at
Recommended
Rehabilitation
Date
Tamarind $520,000 5 17 2020 26
Southridge $700,000 1 28 2012 29
Barbee $320,000 3 32 2016 37
Locust $370,000 4 34 2018 41
Industry $530,000 2 23 2014 26
Total $2,440,000
APPENDIX A
Individual Pump Station Reports
A1 - Tamarind
A2 - Southridge
A3 - Barbee
A4 - Locust
A5 - Industry
City of Fontana - A1-1 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Tamarind Lift Station
The Tamarind Lift Station is located on the west side of Tamarind Avenue, just
north of Jurupa Avenue, as shown in Figure 1. The pump station was originally
constructed in 1994.
Figure 1: Tamarind Lift Station
Pump Station Inflows and Capacities
The Tamarind lift station receives sewage from the surrounding residential
neighborhood through a gravity sewer system. A summary of the pump station
inflows and firm capacity is shown in Table 1. The firm capacity (capacity of
station with one pump out of service) was determined by performing a drawdown
test. The Tamarind lift station has adequate capacity for the both the existing
PWWF and the PDWF.
Table 1: Tamarind Inflows and Capacity
Total #
of
Pumps
Firm
Pumping
Capacity
(gpm)
Existing
PDWF
(gpm)
Existing
PWWF
(gpm)
2 1183 485 650
Tamarind
Lift Station
City of Fontana - A1-2 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Pump Application and Control Strategy
The Tamarind lift station has two 30 hp rail mounted, submersible pumps. The
pumps are adequately sized to convey the PWWF with one pump out of service.
The firm capacity of the station is much larger than the PWWF; therefore it may
be more efficient to use smaller pumps at this station. The size of the pumps and
force main should be evaluated during the next pump station rehabilitation.
The existing pumps have a maximum pump cycle time of approximately 5
minutes (12 starts per hour) assuming the lead pump rotates with every start,
which may be more than what is recommended by the pump manufacturer. If the
pumps sizes are reduced to better match the PWWF, the maximum pump cycle
time will increase to 9 minutes (7 starts per hour), which is typically within the
recommended number of starts for submersible pumps. The pump cycling time
with the proposed pumps should be analyzed during the next pump station
rehabilitation.
Control functions at the Tamarind lift station are accomplished using an Allen-
Bradley MicroLogix PLC. The station has two primary level sensors; a bubbler
and a pressure transducer. The sensor to be used for pump operation can be
selected on the PLC. Additional high and low level float switches are used to
operate the pumps in the event of primary sensor failure, and sends an alarms
through the communication system when they are tripped. The level float
switches are operated through the pump station PLC. In the event of a PLC
failure, there is no means to operate the pumps. The float switches should be
capable of operating the pumps and sending alarms independently from the
primary control system (PLC). This can be achieved by adding a series of relays
to the control panel.
Force Main Evaluation
The Tamarind lift station has a 2240-foot long, 12-inch ductile iron pipe force
main that was constructed in 1994. The force main has a flow velocity of
approximately 3.4 ft/s with one of the existing pumps running, which is within the
recommended range of velocities (between 2 and 10 ft/s). If smaller pumps are
installed in the future, a smaller force main may be required. The City indicated
that there are no known issues with the force main.
There is a bypass pumping connection on the force main that can be used in the
event of a pump station failure.
City of Fontana - A1-3 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Flow Measurement and Monitoring
The Tamarind lift station does not currently have a flow meter. The existing force
main is not exposed at a location where it is feasible to add a flow meter;
therefore, an additional valve vault would be required on the discharge side of
the existing valve vault. The approximate cost to add a flow meter is included in
the cost estimate section of this report.
Electrical Equipment and Motor Control Center Assessment
The existing incoming Southern California Edison (SCE) service (meter
#SCE0728-3159 & transformer #5508355) is rated 125 amps, 480 volts, three
phase. The actual fuse rating of this station was not physically verified since we
were unable to remove the fuse holder. However, based upon the circuitry, the
fuse block maximum rating and the size of the motors operated, a minimum of
125 amp service would be required. The motor control center is a General
Electric 8000 Line with three sections, a controls section and two electronic
reduced voltage starters (one starter per section). The connected load at this
location is two 30 HP motors, station controls and utilization loads (lights & plugs)
The Tamarind pumps use an electronic reduced voltage starter (soft start) as a
starting aid which currently appears to function as necessary. The soft start is
manufactured by WEG #SSW06. The station is relatively new and appears to
have been constructed to comply with more recent codes. Specifically, the
wetwell electrical installation meets the requirements for a hazardous location
(Class 1, Division 1). The electrical room is properly sealed from hazardous
locations and we did not observe any major electrical code violations. There are
some minor clearance issues in the electrical room which, in our opinion, do not
create a safety concern.
Emergency/Backup Power Generation
Standby power at the Tamarind Lift Station is accomplished using a portable
generator via a permanently installed generator receptacle. The generator circuit
is sized to match the incoming service size and has a manual transfer switch
which insures the station is not being fed from two sources simultaneously. The
City currently has a dedicated backup generator for this station that is stored at
the City corporation yard. The generator is a 135 KW engine generator set,
which is adequately sized for the demands at this station.
To start and operate the entire pumping load at this station continuously for 48-
hours (as recommended in the main report), we estimate a required fuel supply
City of Fontana - A1-4 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
of approximately 250 gallons of diesel fuel. To maintain a reliable electrical
system at the lift station, the City would need to have the resources to move and
install the generator set and provide the fuel supply for continuous operation.
There may be sufficient space at the existing site to add a permanent generator.
We recommend adding a permanent generator to this pump station if it is
deemed feasible.
The time to overflow at the Tamarind pump station is 4.2 hours during the PDWF
and 3.2 hours during the PWWF. The City should have a response plan in place
to respond to this station, prior to an overflow, with a portable generator in the
event of a power failure.
Communication and Monitoring
Communication from the Tamarind Lift Station is one way using a dialer
connected to a telephone land line to report alarm conditions to a central
location. The dialer is manufactured by RACO Verbatim VSS series. The
communications system sends a limited amount of information to the monitoring
station; specifically, only alarm signals are sent out. The existing telephone
system does not receive control signals from the monitoring station; therefore,
the station can not be operated remotely.
The existing communications system does not currently convey all of the
recommended alarm information to the monitoring station. The communications
system shall be capable of sending an alarm in the event of a communication
failure. This can be accomplished by installing a backup cellular alarm system
that sends an alarm in the event of a primary communication failure, or by
replacing the existing system with a radio telemetry system. A list of the
recommended and current pump station alarms are shown in Table 2. It may be
necessary to expand on the current system as the station is upgraded and
additional alarms and data is desired.
City of Fontana - A1-5 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 2: Current Station Alarms
Recommended Alarms
Tamarind Pump
Station Alarms
Communication Failure
Power Failure X
Building Entry
Wetwell Entry
Battery Low
Pump Failure X
High Level X
Low Level X
Structural and Seismic Assessment
The Tamarind pump station is in good overall condition. Behind the pump station
is a masonry block wall which retains a sloped hill which has developed an open
crack in the grout and mortar cap along the top course of masonry blocks at one
location. This crack should be filled with grout or silicone or polyurethane joint
sealer to help prevent water intrusion and any further wall deterioration. The
wetwell is in good condition with no visible cracks or plant roots. Safety railings
are in good condition with no observed rust or concrete spalling. The inside face
of the frame at the top of the wetwell which the hatches bear on, shows
significant rust and pitting of the steel. However, the portion of the frame where
the hatch rests appears to be in good condition with no appreciable loss of
capacity. We recommend this steel be cleaned and painted to prevent further
deterioration. The hatch and hinges are in good condition. There are two
threaded hooks protruding just below the inside of the hatch frame with one
being noticeably bent. The bent hook should be replaced to ensure proper
strength and prevent premature failure. The concrete surrounding the wetwell
has settled downward and away from the wetwell in some locations. Gaps
should be sealed with a silicone or polyurethane joint sealer and monitored for
any further settlement of the concrete. The valve vault is in good condition along
with the hatches. It was observed that the precast top portion of the vault was
slightly shifted relative to the rest of the vault. This likely occurred during the
construction of the vault and does not require repair.
The electrical equipment for this pump station is located in a separate small
masonry block building. No cracking in the blocks or grout was observed in the
walls and lintel above the door. The concrete slab/foundation was in good
condition with no visible cracks. The building has a wood framed roof made of
carpenter trusses with asphalt shingles. The building has ventilation openings in
City of Fontana - A1-6 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
the gable ends and no water damage was visible on the trusses or roof plywood.
The three electrical equipment cabinets inside the building are bolted onto a rail.
However, on the 2 electrical cabinets we could access, only 1 anchor bolt was
visible connecting the rail to the concrete slab. The cabinets were not anchored
at the top. We were unable to determine if the electrical cabinets are properly
anchored for safety as required by Code (see ASCE 7-05 Chapter 13.4). No as-
built structural drawings were provided for this structure. Further evaluation
would be required to determine if the existing structure is adequate to resist
current Code seismic forces.
The following of the Tamarind pump station show the discussed structurally
deficient items.
Open crack in retaining wall mortar cap
Wetewll frame rust
Concrete settlement and movement
Bent support hook at wetwell and frame rust
City of Fontana - A1-7 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Concrete settlement
Miscellaneous Site Improvements
The City’s O&M staff indicated that the mastic coating on the bottom of the
wetwell is deteriorated. Additionally, the T-lock wetwell lining is peeling off near
the pipe penetrations. We recommend removing the existing lining and re-lining
the wetwell during the next pump station rehabilitation.
Pump Station Reliability
As previously discussed, the EPA and RWQCB have required cities to certify
their sanitary sewer pump stations for reliability. The reliability deficiencies and
recommended correction actions identified for the Tamarind lift station are listed
in Table 3.
Table 3: Tamarind Lift Station Reliability Deficiencies
Reliability Deficiency Corrective Action
Alarms Inoperable in the event of a Phone
Line Failure
Install backup cellular alarm system, or replace
with radio telemetry
Secondary Controller not Independent from
Primary
Modify existing controls so that backup floats are
independent from primary controller (PLC).
City of Fontana - A1-8 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Cost Estimates / Recommended Improvements
The immediate recommended improvements and the estimated construction
costs for the Tamarind lift station are shown in Table 4.
Table 4: Tamarind Immediate Improvements Cost Estimate
Improvement Cost
Modify Alarm System $5,000
Modify Secondary Controller $2,000
Total $7,000
55% for Contingency, Admin., CM, Engr. $4,000
Total w/ Contingency $11,000
The cost estimate to perform a full rehabilitation on the Tamarind lift station is
shown in Table 5. This estimate assumes all items within the pump station will
be replaced, including those included in the immediate improvement list.
City of Fontana - A1-9 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 5: Tamarind Lift Station Cost Estimate
Item Size Make / Material Comments
Current
Replacement
Cost
Pumps and Motors
Pump and Motor #1 30 HP Submersible $25,000
Pump and Motor #2 30 HP Submersible $25,000
Subtotal $50,000
Electrical Equipment
Electrical Panel $25,000
SCADA System (Site Only) RTU & Assoicated Equipment $5,000
Level Sensor Ultrasonic w/ Backup Float $10,000
Backup Generator Replace Portable $40,000
Miscellaneous Wiring, coduit, etc. $5,000
Subtotal $85,000
Piping
Discharge Piping 8 inch Ductile Iron 80 LF @ $200/ LF $16,000
Fittings 8 inch Ductile Iron 4 EA @ $800 / EA $3,200
Check Valves 8 inch Ductile Iron (body) 2 EA @ $2000 / EA $4,000
Gate Valves (isolation) 8 inch Ductile Iron (body) 2 EA @ $2000 / EA $4,000
Subtotal $27,200
Miscellaneous Equipment
Flow Meter (optional) $7,000
Flow Meter Vault & Access Hatch (optional) $20,000
Wet Well Rehabilitation & Mods Structural Repair and Coating $30,000
Pump Rail 4 EA @ $1000 / EA $4,000
Building Rehabilitation & Mods $20,000
Misc. Site Improvements Pavement, Fencing, etc. $25,000
Bypass Pumping During Construction $40,000
Demolition & Disposal $30,000
Subtotal $176,000
Total $338,200
55% for Contingency, Admin., CM, Engr. $186,000
Total w/ Contingency $520,000
Notes:
1. Costs referenced to June 2011 Los Angeles Construction Cost Index (10051.30)
2. Costs include materials, labor, demolition and hauling
This estimate of construction cost is a professional opinion, based upon the engineer's experience with the design and
construction of similar projects. It is prepared only as a guide and is subject to change. Schaaf & Wheeler and its
subconsultants make no warranty, whether expressed or implied, that the actual costs will not vary from these estimated
costs, and assumes no liability for such variances.
25- Year Replacement Cost
City of Fontana - A1-10 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 1: Tamarind Pump Station
Photo 2: Control Panel
City of Fontana - A1-11 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 3: Wetwell
City of Fontana - A2-1 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Southridge Lift Station
The Southridge Lift Station is located on the northwest corner of Philadelphia
Avenue and Vintage Place, as shown in Figure 1. The pump station was
originally constructed in 1985, and it has three pumps. Minor pump station
improvements and upgrades have been performed since it was originally
constructed.
Figure 1: Southridge Lift Station
Pump Station Inflows and Capacities
The Southridge lift station receives sewage from the surrounding residential
neighborhood through a gravity sewer system. A summary of the pump station
inflows and firm capacity is shown in Table 1. The firm capacity (capacity of
station with one pump out of service) was determined by performing a drawdown
test. The Southridge lift station does not have adequate capacity for the existing
PWWF.
Table 1: Southridge Inflows and Capacity
Total #
of
Pumps
Firm
Pumping
Capacity
(gpm)
Existing
PDWF
(gpm)
Existing
PWWF
(gpm)
3 790 714 957
Southridge
Lift Station
City of Fontana - A2-2 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Pump Application and Control Strategy
The Southridge lift station has three 30 hp submersible pumps. The current
control logic is such that only two pumps will run simultaneously. The pump
station firm capacity is close to the PWWF; therefore, it may be possible to
rebuild the existing pumps or replace the impellers to meet the PWWF.
However, the pumps are currently 27 years old, which is close to the
recommended service life of sewage pumps. Therefore, we recommend
replacing the pumps. Based on Flygt pumps, we estimate that new pumps
adequately sized for the PWWF will have to be approximately 20 hp each.
Though these have less hp than the existing pumps, the new pumps would be
more efficient and have a larger capacity.
With new pumps adequately sized for the PWWF and utilizing the existing
wetwell (with lead pump rotating with every start), the station will have a
maximum pump cycle time of approximately 19 minutes (3 starts per hour), which
should be within the manufacturers recommendations for maximum pump
cycling. Therefore, the pump station wetwell is adequately sized to allow for
proper pump cycling times.
Pump #1 was out of service during the pump station inspection; however, it was
expected to be back online shortly. Pump drawdown tests were only based on
pump #2 and pump #3. It was assumed that pump #1 has a similar capacity to
the other pumps.
Control functions at the Southridge lift station are accomplished using an Allen-
Bradley MicroLogix PLC. The station has two primary level sensors; a bubbler
and a pressure transducer. The sensor to be used for pump operation can be
selected on the PLC. Additional high and low level float switches are used to
control the pumps in the event of primary sensor failure, and sends an alarms
through the communication system when they are tripped. The level float
switches are operated through the pump station PLC. In the event of a PLC
failure, there is no means to operate the pumps. The float switches should be
capable of operating the pumps and sending alarms independently from the
primary control system (PLC). This can be achieved by adding a series of relays
to the control panel.
Force Main Evaluation
The Southridge lift station has a 10-inch ductile iron pipe force main that was
constructed in 1983. The force main has a flow velocity of approximately 3.9 ft/s,
City of Fontana - A2-3 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
which is within the recommended range of velocities (between 2 and 10 ft/s).
The City indicated that there are no known issues with the force main. However,
due to its age, the condition should be further evaluated during the next pump
station rehabilitation.
The existing force main is 2600 feet long; therefore, in order to convey the
inflows in the event of a pump station failure a bypass pumping connection
should be installed on the force main. There appears to be sufficient room to add
a bypass pumping connection within the drywell, or in the existing vault on the
south side of the existing pump station building (if a flow meter is not installed
here).
Flow Measurement and Monitoring
The Southridge lift station does not currently have a flow meter. However, there
is an existing vault that may be able to accommodate the installation of a flow
meter. The addition of a flow meter at this station would be valuable considering
the large inflows and the ease of installation. The approximate cost to install a
flow meter is included within the cost estimate section of this report.
Electrical Equipment and Motor Control Center Assessment
The existing incoming Southern California Edison (SCE) service (meter
#SCE259000-014627) is rated 400 amps (400 amp rating plug), 480 volts, three
phase. The existing main service disconnect is a 600 amp circuit breaker frame
with a 400 amp rating plug, which can be easily changed if necessary. This
station has ground fault protection located at the main service disconnect.
The switch gear line up and the motor control center is manufactured by Cutler-
Hammer with three electronic reduced voltage starters for the three 30 HP
pumps. The Southridge pumps use an electronic reduced voltage starter (soft
start) as a starting aid which currently appears to control the pumps as
necessary. The soft start is manufactured by WEG #SSW07. Maintenance
personnel report that these soft starts have had a problem with overheating at
this location.
Emergency/Backup Power Generation
Standby power at the Southridge Lift Station is accomplished using a
permanently installed 125 KW/156 KVA generator with an automatic transfer
switch. Fuel for the generator is provided from a skid mounted fuel tank. The
City of Fontana - A2-4 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
fuel tank capacity is estimated to be 350 gallons of diesel fuel (estimate base
upon outside dimensions of the tank of 48”x116”x15”). The fuel tank is reportedly
not double walled and there is no leak detection equipment in place.
Furthermore, the permanent location of the generator is approximately 28” from
the pump station building. This space does not offer adequate working clearance
between the generator and the building.
The generator circuit is sized for a 200 amp circuit protection, the actual circuit
breaker was not accessible and its rating was not observed. The generator is
sized for the connected load and has the capacity to start and operate the entire
station. Decreasing the pump sizes to the proposed three motors at 20 HP
apiece would decrease the generator load. To start and operate the entire
existing pumping load at this station continuously for 48-hours (as recommended
in the main report), we estimate a required fuel supply of approximately 365
gallons of diesel fuel. Similarly, with the proposed load with new pumps the fuel
consumption is expected to be about 243 gallons of diesel fuel over the operating
period. To maintain a reliable electrical system at the lift station, the City would
need to have the resources to provide the fuel supply noted for continuous
operation.
The Southridge lift has wiring for a portable generator receptacle. We
recommend installing a receptacle so that a portable generator could be used at
this station if necessary.
The time to overflow at the Southridge pump station is 1.9 hours during the
PDWF and 1.4 hours during the PWWF. In the event of a pump station failure,
this is the estimated time the City will have to respond before an overflow occurs.
Once the pump station reliability deficiencies are taken care of the likelihood of a
station failure is minimal because the station will have fully redundant
mechanical, electrical, and power systems.
Communication and Monitoring
Communication from the station is one way using a dialer connected to a
telephone land line to report alarm conditions to a central location. The dialer is
manufactured by RACO Verbatim VSS series. The communications system
sends a limited amount of information to the monitoring station; specifically, only
alarm signals are sent out. The existing telephone system does not receive
control signals from the monitoring station; therefore, the station can not be
operated remotely.
City of Fontana - A2-5 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
The existing communications system does not currently convey all of the
recommended alarm information to the monitoring station. The communications
system shall be capable of sending an alarm in the event of a communication
failure. This can be accomplished by installing a backup cellular alarm system
that sends an alarm in the event of a primary communication failure, or by
replacing the existing system with a radio telemetry system. A list of the
recommended and current pump station alarms are shown in Table 2. It may be
necessary to expand on the current system as the station is upgraded and
additional alarms and data is desired.
Table 2: Current Station Alarms
Recommended Alarms
Southridge Pump
Station Alarms
Communication Failure
Power Failure X
Building Entry
Battery Low
Pump Failure X
High Level X
Low Level X
Dry Well Flooding X
Structural and Seismic Assessment
The Southridge pump station is in good overall condition. Surrounding the pump
station is a 6ft tall masonry block wall supported on a concrete footing which
retains approximately 1ft of soil on the street side and is covered with a stucco
finish. The exterior stucco shows both vertical cracks and stepped cracks
following the masonry joints on both sides of the wall and along various areas of
the wall. Currently the exterior stucco does not have much spalling, but
continued cracking could cause the stucco to separate from the wall. Review of
the provided as-built drawings for this pump station indicates the existing wall
has #4@32” on center for vertical reinforcement. Also, the existing as-built
drawings indicate the exterior was not originally designed to retain any soil, which
increases the loading and demand on the wall and footing. The footing size and
reinforcement is not adequate to resist current Code specified seismic forces
(ASCE 7-05 chapter 13). This wall has insufficient factors of safety for both
strength and stability for a code level seismic event and may be prone to failure
during an earthquake. Due to the low occupancy rate of the pump station the life
safety risk for maintenance personnel is low, but a risk nonetheless. The portion
of wall behind the back of the building has the possibility of damaging the
City of Fontana - A2-6 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
building if the wall were to collapse under a seismic event. The wall located
behind the back of sidewalk along Philadelphia Avenue poses a much greater life
safety risk to the public due to its close proximity. Retrofit is recommended in the
near future in the regions where life safety or structure damage is a concern.
Long term, a full retrofit or replacement is recommended. Exterior concrete pads
are in good condition. The emergency generator is supported by a steel frame
which is anchored to the concrete pad. Next to the generator there is a yellow
cabinet which has a “Hazardous Waste” label on each front door which is
currently unanchored and resting on two pieces of wood. The feet of the cabinet
are currently sinking into the wood supports which could cause the cabinet to
become unbalanced and fall over. Without a positive connection between the
cabinet and the ground the cabinet is unstable during seismic events and should
be properly anchored for safety as required by Code (see ASCE 7-05 Chapter
13.4).
The pump station building is a wood framed structure with diagonal 1x8
sheathing on the exterior walls, drywall on the inside of the walls, and an asphalt
shingle covered roof. The wood roof is in good condition with signs of previous
water leakage, however the roof framing looked dry even though it was raining
during the inspection and for much of the morning prior to arriving. The exterior
ends of the ridge beam, eave beam, and roof rafters are starting to split at the
ends due to exposure to weather. This is not a structural concern since these
portions of the beams are non-structural. Further monitoring should be
performed to insure this does not spread to the structural portion of the beams.
On the inside of the building the corner closest to the doors and along the east
wall shows some water damage and deterioration of the wood and drywall.
These areas should have the drywall removed and inspected further to determine
if any wood framing replacement is necessary.
The ground floor concrete floor has been sealed such that the concrete condition
could not be determined. The maintenance personnel stated no large cracks
were visible before the seal was applied and the bottom of this floor shows no
cracking. The electrical equipment cabinets rest on a concrete slab that has a
large transverse crack near the middle of the building. Review of the as-built
drawings indicates that this pad contains no reinforcement which would prevent
cracking. Since no large equipment is located near the crack no action is
currently needed.
City of Fontana - A2-7 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
The electrical equipment cabinets inside the building are bolted onto a rail. The
rail in turn is bolted to the floor, however, very few anchor bolts were visible
connecting the rail to the concrete slab. The cabinets were not anchored at the
top or back. We were unable to determine if the electrical cabinets are properly
anchored for safety as required by Code (see ASCE 7-05 Chapter 13.4). Also,
since the concrete equipment pad is not positively connected to the main slab,
any anchors would need to be installed through the pad and into the main slab to
provide adequate resistance during a seismic event. The visual inspection and
review of the as-built drawings indicates the structure contains the typical
elements to resist seismic forces, however only a detailed analysis of the
structure can determine if it will perform adequately under current code specified
seismic forces (ASCE 7-05 Chapter 12).
The wetwell was not inspected during this visit. The drywell is in good condition.
The stairway and catwalk steel shows no distress or rust. All anchorages to the
exterior concrete walls are in good condition with no observed cracking at the
connection points. No major cracking was observed in the drywell walls or
ceiling. Small cracks were observed in the sealed floor however they are minor
and require no action. Pumps and piping appear to be adequately supported on
concrete blocks, metal wall brackets or small metal posts which are anchored to
the walls and floor. Large diameter elevated pipes have additional supports to
resist lateral loads and pump drive shafts are positively attached to the vertical
catwalk steel. The fresh air duct work is also braced to the wall with angle
brackets. The inlet pipe manhole was in good condition with no visible cracks or
plant roots.
Perimeter block wall
Unanchored storage cabinet
City of Fontana - A2-8 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Deterioration of beams at outer ends
Deterioration of rafter ends
Water damage to drywall and framing
Water damage to drywall and framing
Miscellaneous Site Improvements
The Southridge lift station electrical room is located atop the station drywell and
is open to the drywell below. Since the electrical room is open to the drywell, it
takes on the same hazardous location classification as the drywell. According to
NFPA 820, sewage drywells are Class 1 Division 2 Hazardous Location and the
electrical installation is required to meet this classification. Explosion proof
equipment is required in Class 1 Division 2 hazardous locations. Drywells and
connected areas can be considered unclassified if they are continuously
ventilated with a forced in and forced out system that has a minimum of six (6) air
changes per hour.
The existing ventilation at the Southridge lift station is a forced air in system that
City of Fontana - A2-9 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
is controlled by a thermostat and a manual switch, and therefore, does not meet
the requirements for an unclassified area. Furthermore, the capacity of the
ventilation system is unknown and, therefore, it is uncertain if the ventilation
system is capable of the required air changes in the drywell and the electrical
room. We recommend installing a new ventilation system that meets these
requirements so that the drywell and control room is “unclassified” and explosion
proof equipment is not required.
Pump Station Reliability
As previously discussed, the EPA and RWQCB have required cities to certify
their sanitary sewer pump stations for reliability. The reliability deficiencies
identified for the Southridge lift station are listed in Table 3.
Table 3: Southridge Lift Station Reliability Deficiencies
Reliability Deficiency Corrective Action
Insufficient Capacity
Increase Pumping Capacity to Meet the PWWF
with Two Pumps
No Bypass Pumping Connection Install bypass pumping connection
Alarms Inoperable in the event of a Phone
Line Failure
Install backup cellular alarm system, or replace
with radio telemetry
Secondary Controller not Independent from
Primary
Modify existing controls so that backup floats are
independent from primary controller (PLC).
Cost Estimates / Recommended Improvements
The immediate recommended improvements and the estimated construction
costs for the Southridge lift station are shown in Table 4.
Table 4: Southridge Immediate Improvements Cost Estimate
Improvement Cost
Increase Pumping Capacity to Meet PWWF $60,000
Replace Ventilation System $20,000
Modify Alarm System $5,000
Modify Secondary Controller $2,000
Add Bypass Pumping Connection (in drywell) $5,000
Total $92,000
55% for Contingency, Admin., CM, Engr. $51,000
Total w/ Contingency $143,000
The cost estimate to perform a full rehabilitation on the Southridge lift station is
shown in Table 5. This estimate assumes all items within the pump station will
be replaced, including those included in the immediate improvement list.
City of Fontana - A2-10 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 5: Southridge Lift Station Cost Estimate
Item Size Make / Material Comments
Current
Replacement
Cost
Pumps and Motors
Pump and Motor #1 20 HP Flygt Submersible $15,000
Pump and Motor #2 20 HP Flygt Submersible $15,000
Pump and Motor #3 20 HP Flygt Submersible $15,000
Subtotal $45,000
Electrical Equipment
Electrical Panel $30,000
SCADA System (Site Only) RTU & Assoicated Equipment $5,000
Level Sensor Ultrasonic w/ Backup Float $10,000
Backup Generator $50,000
Miscellaneous Wiring, coduit, etc. $15,000
Subtotal $110,000
Piping
Discharge Piping 8-10 inch Ductile Iron 120 LF @ $200/ LF $24,000
Fittings 8-10 inch Ductile Iron 9 EA @ $2000 / EA $18,000
Check Valves 8 inch Ductile Iron (body) 3 EA @ $3000 / EA $9,000
Gate Valves (isolation) 8 inch Ductile Iron (body) 6 EA @ $3000 / EA $18,000
Bypass Pumping Connection in drywell $5,000
Subtotal $74,000
Miscellaneous Equipment
Flow Meter (optional) $10,000
Wet Well Rehabilitation & Mods Structural Repair and Coating $30,000
Building Rehabilitation & Mods $40,000
Seismic Retrofit Wall Surrounding Station $20,000
Ventilation System $20,000
Misc. Site Improvements Pavement, Fencing, etc. $25,000
Bypass Pumping During Construction $50,000
Demolition & Disposal $30,000
Subtotal $225,000
Total $454,000
55% for Contingency, Admin., CM, Engr. $250,000
Total w/ Contingency $700,000
Notes:
1. Costs referenced to June 2011 Los Angeles Construction Cost Index (10051.30)
2. Costs include materials, labor, demolition and hauling
This estimate of construction cost is a professional opinion, based upon the engineer's experience with the design and
construction of similar projects. It is prepared only as a guide and is subject to change. Schaaf & Wheeler and its
subconsultants make no warranty, whether expressed or implied, that the actual costs will not vary from these estimated
costs, and assumes no liability for such variances.
25- Year Replacement Cost
City of Fontana - A2-11 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 1: Southridge Pump Station
Photo 2: Electrical Panel
City of Fontana - A2-12 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 3: Drywell
Photo 4: Vault on South Side of Building – Corrosion on Force Main
City of Fontana - A3-1 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Barbee Lift Station
The Barbee lift station is located on the south side of Barbee Street, just west of
the intersection of Barbee Street and Grace Avenue, as shown in Figure 1. The
pump station was originally constructed in 1979. Minor pump station
improvements and upgrades have been performed since it was originally
constructed.
Figure 1: Barbee Lift Station
The possibility of replacing the Barbee lift station with a gravity system was
analyzed. Based on evaluation of the base map information provided by the City,
we estimate that approximately 2,800 LF of 8" gravity sewer line would need to
be replaced. The resulting slope from City manhole M19_5 on Barbee Street to
L19_26 on Alder would be approximately 0.44%. The excavation would be
relatively deep (approximately 12 feet) for portions of the line, and approximately
27 existing laterals will need to be reconnected to the new, lower, gravity line. A
rough estimate of construction cost for this project is $1,600,000 which includes
an additional 55% for contingency, administration, CM, and Engineering.
Pump Station Inflows and Capacities
The Barbee lift station receives sewage from the surrounding residential
neighborhood through a gravity sewer system. A summary of the pump station
inflows and firm capacity is shown in Table 1. The firm capacity (capacity of
Barbee Lift
Station
City of Fontana - A3-2 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
station with one pump out of service) was determined by performing a drawdown
test. The Barbee lift station does not have adequate capacity for the existing
PWWF or the PDWF.
Table 1: Barbee Inflows and Capacity
Pump Application and Control Strategy
The Barbee lift station has two 1 hp submersible pumps. City personnel
indicated that one pump was recently replaced. The current pump station control
logic runs both pumps simultaneously so that the inflows can be adequately
conveyed without surcharging the upstream gravity system. Both pumps should
be replaced so that each pump is capable of conveying the PWWF. Based on
Barnes pumps, we estimate that new pumps adequately sized for the PWWF will
have to be approximately 3 hp each. As discussed in the force main evaluation
section within this report, we recommend replacing or lining the 8-inch section of
the force main with a 4-inch force main. The recommended pump selections to
meet the PWWF for the various force main scenarios are shown below. Due to
the unknown condition of the existing force main, the actual discharge from each
pump after installation should be confirmed to ensure they are operating at or
above the PWWF.
Force Main Recommended Pump
Existing System (4" and 8" force main) Barnes Series XSGV-L, 4.25" Impeller
Recommended Improved Force Main (4") Barnes Series XSGV-L, 4.5" Impeller
With two new pumps adequately sized for the PWWF within the existing wetwell
(with lead pump rotating with every start), the station will have a maximum pump
cycle time of approximately 11 minutes (6 starts per hour); which should be
within the manufacturers recommendations for maximum pump cycling.
Therefore, the pump station wetwell is adequately sized to allow for proper pump
cycling times.
Control functions at the Barbee lift station are accomplished using an Allen-
Bradley MicroLogix PLC. The primary wetwell level sensor is a bubbler, which
controls the operation of the pumps (both pumps on, both pump off). Additional
Total #
of
Pumps
Firm
Pumping
Capacity
(gpm)
Existing
PDWF
(gpm)
Existing
PWWF
(gpm)
2 47 66 88
City of Fontana - A3-3 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
high and low level float switches are used to operate the pumps in the event of
primary sensor failure, and sends an alarms through the communication system
when they are tripped. The level float switches are operated through the pump
station PLC. In the event of a PLC failure, there is no means to operate the
pumps. The float switches should be capable of operating the pumps and
sending alarms independently from the primary control system (PLC). This can
be achieved by adding a series of relays to the control panel.
Force Main Evaluation
The Barbee lift station has a 4-inch PVC pipe force main for approximate 380
feet, then a 4-inch steel pipe for 50 feet, then an 8-inch VCP pipe for another
1170 feet. The steel and VCP sections of the force main were originally
constructed in 1971 and the PVC section was constructed in 1979. The 4-inch
force main, once the pumps are upgraded to handle the PWWF, will have a flow
velocity of approximately 2.3 ft/s, which is within the recommended range of
velocities (between 2 and 10 ft/s). The 8-inch force main will have a flow velocity
of approximately 0.6 ft/s, which is well below the recommended minimum
velocity. Low velocities can lead to settling of solids and the force main may
eventually become clogged and inoperable.
We recommend replacing or sliplining the existing 8-inch force main with a 4-inch
force main. If the City decides to continue to use the 8-inch force main we
recommend inspecting the existing line and routinely running both pumps to
create higher velocities for flushing.
The City indicated that there are no known issues with the force main. However,
due to its age, the condition should be further evaluated during the next pump
station rehabilitation.
The existing force main is 1600 feet long; therefore, in order to convey the
inflows in the event of a pump station failure a bypass pumping connection
should be installed on the force main. There appears to be sufficient room to add
a bypass pumping connection within the existing valve vault, this may require
moving the existing valves closer to the wetwell and removing a short section of
the force main.
City of Fontana - A3-4 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Flow Measurement and Monitoring
The Barbee lift station does not currently have a flow meter. The station has a
relatively low inflow, so flow monitoring at this station may not be necessary
unless the City is interested in the generation rates within the sewershed and the
operating rate of the lift station.
The existing force main is not exposed at a location where it is feasible to add a
flow meter; therefore, an additional valve vault would be required on the
discharge side of the existing valve vault. The estimated cost to add a flow meter
at this station is included in the cost estimate within this report.
Electrical Equipment and Motor Control Center Assessment
The existing incoming Southern California Edison (SCE) service (meter #SCE
85-561992) is rated 30 amps, 120/240 volts, single phase. Electrical equipment
is housed inside of a weather rated equipment pedestal. The motor controller
uses a variable frequency drive (WEG; Vector Inverter Plus series) to establish a
third phase to operate a 1 HP three phase motor. There are two motors
operating at this location each with its own variable frequency drive. The existing
service is adequate for the existing loads, but it is very small, and if the load were
increased significantly the service capacity would likely have to be increased.
There are unsealed conduits from the wet well into the equipment pedestal which
is not California Electric Code compliant. That is, since the wet well is
considered a hazardous location (Class 1 Division 1), unsealed conduits allow
gas to be transmitted into the equipment pedestal, requiring the equipment
pedestal to be classified similarly.
Emergency/Backup Power Generation
Standby power at the Barbee Lift Station is accomplished using a portable
generator via a permanently installed generator receptacle. The generator circuit
is sized to match the incoming service size and has a manual transfer switch
which insures the station is not being fed from two sources simultaneously. The
City has a dedicated 15 KW backup generator for this station that is kept at the
City corporation yard.
To start and operate the entire existing pumping load at this station continuously
for 48-hours (as recommended in the main report), we estimate a required fuel
supply of less that 20 gallons of diesel fuel. Increasing the pump sizes to the
proposed two motors at 3 HP apiece could still be supported using the 15 KW
City of Fontana - A3-5 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
generator; however, the fuel consumption would increase to an estimated 50
gallons over the operating period. To maintain a reliable electrical system at the
lift station, the City would need to have the resources to move and install the
generator set and provide the fuel supply for continuous operation.
The time to overflow at the Barbee pump station is 2.4 hours during the PDWF
and 1.8 hours during the PWWF. The City should have a response plan in place
to respond to this station, prior to an overflow, with a portable generator in the
event of a power failure.
Communication and Monitoring
Communication from the station is one way using a dialer connected to a
telephone land line to report alarm conditions to a central location. The dialer is
manufactured by RACO Verbatim VSS series. The communications system
sends a limited amount of information to the monitoring station; specifically, only
alarm signals are sent out. The existing telephone system does not receive
control signals from the monitoring station; therefore, the station can not be
operated remotely.
The existing communication system does not currently convey all of the
recommended alarm information to the monitoring station. The communication
system shall be capable of sending an alarm in the event of a communication
failure. This can be accomplished by installing a backup cellular alarm system
that sends an alarm in the event of a primary communication failure, or by
replacing the existing system with a radio telemetry system. A list of the
recommended and current pump station alarms are shown in Table 2. It may be
necessary to expand on the current communication system as the station is
upgraded and additional alarms and data is desired.
Table 2: Current Station Alarms
Recommended Alarms
Barbee Pump
Station Alarms
Communication Failure
Power Failure X
Control Panel Entry
Wetwell Entry
Battery Low
Pump Failure X
High Level X
Low Level X
City of Fontana - A3-6 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Structural and Seismic Assessment
The Barbee pump station is in good overall condition. The electrical cabinet is
resting on a concrete slab in good condition and was anchored at each corner.
The wet well had tree roots coming through the side which are trimmed
approximately once a month according to the maintenance personnel. There is
some concrete spalling just below the manhole frame steel. The vault containing
the valves is in good condition along with the diamond plate cover and support
frame. Currently the piping within the valve vault is supported on stacked pieces
of CMU blocks and wood. This support should be replaced with a more
permanent support that is anchored so it remains stable under a seismic event.
It was observed that the sidewalk around the wet well and pump vault has settled
up to 2 inches. This may have been caused by improper compaction after
installation of the below grade structures. No action is currently required,
however the settlement should be monitored to ensure it does not worsen which
could possibly indicate other issues.
Concrete spalling at manhole frame and tree roots
Concrete spalling at manhole frame and tree roots
City of Fontana - A3-7 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Pipes supported on stacked CMU blocks
Pipes supported on stacked CMU blocks
Sidewalk settlement
Sidewalk settlement
Miscellaneous Site Improvements
Due to its close proximity to the street and associated vehicle traffic, bollards
should be placed around the electrical panel to protect it from possible collision.
The wetwell experiences severe root intrusion that requires cleaning every
couple of months. To remedy this problem and decrease required maintenance,
the wetwell should be lined during the next pump station rehabilitation.
Pump Station Reliability
As previously discussed, the EPA and RWQCB have required cities to certify
their sanitary sewer pump stations for reliability. The reliability deficiencies
identified for the Barbee lift station are listed in Table 3.
City of Fontana - A3-8 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 3: Barbee Lift Station Reliability Deficiencies
Reliability Deficiency Corrective Action
Insufficient Capacity
Increase Pumping Capacity to Meet the PWWF
with One Pump
No Bypass Pumping Connection Install bypass pumping connection
Alarms Inoperable in the event of a Phone
Line Failure
Install backup cellular alarm system, or replace
with radio telemetry
Secondary Controller not Independent from
Primary
Modify existing controls so that backup floats are
independent from primary controller (PLC).
Cost Estimates / Recommended Improvements
The immediate recommended improvements and the estimated construction
costs for the Barbee lift station are shown in Table 4.
Table 4: Barbee Immediate Improvements Cost Estimate
Improvement Cost
Increase Pumping Capacity to Meet PWWF (may require
new power service and panel upgrades) $45,000
Install Bypass Pumping Connection $5,000
Construct Permanent Pipe and Valve Supports within
Vault $3,000
Total $53,000
55% for Contingency, Admin., CM, Engr. $29,000
Total w/ Contingency $82,000
The cost estimate to perform a full rehabilitation on the Barbee lift station is
shown in Table 5. This estimate assumes all items within the pump station will
be replaced, including those items within the immediate improvement list.
City of Fontana - A3-9 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 5: Barbee Lift Station Cost Estimate
Item Size Make / Material Comments
Current
Replacement
Cost
Pumps and Motors
Pump and Motor #1 3 HP Barnes Submersible $7,000
Pump and Motor #2 3 HP Barnes Submersible $7,000
Subtotal $14,000
Electrical Equipment
Electrical Panel $15,000
SCADA System (Site Only) RTU & Assoicated Equipment $5,000
Level Sensor Ultrasonic w/ Backup Float $10,000
Backup Generator Portable $20,000
New Power Service $20,000
Miscellaneous Wiring, coduit, etc. $5,000
Subtotal $75,000
Piping
Discharge Piping 4 inch Ductile Iron 40 LF @ $100/ LF $4,000
Fittings 4 inch Ductile Iron 4 EA @ $400 / EA $1,600
Check Valves 4 inch Ductile Iron (body) 2 EA @ $1000 / EA $2,000
Gate Valves (isolation) 4 inch Ductile Iron (body) 2 EA @ $1000 / EA $2,000
Bypass Pumping Connection $5,000
Subtotal $14,600
Miscellaneous Equipment
Flow Meter (optional) $6,000
Flow Meter Vault & Access Hatch (optional) $20,000
Wet Well Rehabilitation & Mods Structural Repair and Coating $30,000
Pump Rail 4 EA @ $1000 / EA $4,000
Misc. Site Improvements Pavement, Fencing, etc. $25,000
Bypass Pumping During Construction $10,000
Demolition & Disposal $10,000
Subtotal $105,000
Total $208,600
55% for Contingency, Admin., CM, Engr. $115,000
Total w/ Contingency $320,000
Notes:
1. Costs referenced to June 2011 Los Angeles Construction Cost Index (10051.30)
2. Costs include materials, labor, demolition and hauling
This estimate of construction cost is a professional opinion, based upon the engineer's experience with the design
and construction of similar projects. It is prepared only as a guide and is subject to change. Schaaf & Wheeler and
its subconsultants make no warranty, whether expressed or implied, that the actual costs will not vary from these
estimated costs, and assumes no liability for such variances.
25- Year Replacement Cost
City of Fontana - A3-10 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 1: Barbee Pump Station
City of Fontana - A3-11 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 2: Wetwell
Photo 3: Existing Valve Vault
City of Fontana - A4-1 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Locust Lift Station
The Locust Lift Station is located on the northeast corner of Locust Avenue and
Athol Street, as shown in Figure 1. The pump station was originally constructed
in 1977. Minor pump station improvements and upgrades have been performed
since it was originally constructed, including an electrical panel replacement in
2000.
Figure 1: Locust Lift Station
Pump Station Inflows and Capacities
The Locust lift station receives sewage from the surrounding residential
neighborhood through a gravity sewer system. A summary of the pump station
inflows and firm capacity is shown in Table 1. The firm capacity (capacity of
station with one pump out of service) was determined by performing a drawdown
test. The Locust lift station does not have adequate capacity for the existing
PWWF or the PDWF.
Table 1: Locust Inflows and Capacity
Total #
of
Pumps
Firm
Pumping
Capacity
(gpm)
Existing
PDWF
(gpm)
Existing
PWWF
(gpm)
2 70 120 161
Locust Lift
Station
City of Fontana - A4-2 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Pump Application and Control Strategy
The Locust lift station has two 5 hp pumps as indicated on the pump station
rehabilitation record drawings. The pump station drywell was not accessed
during the site visit due to confined space regulations. Both pumps should be
replaced so that each pump is capable of conveying the PWWF. Based on Flygt
pumps, we estimate that new pumps adequately sized for the PWWF will have to
be approximately 7.5 hp each. We recommend installing rail-mounted
submersible pumps in the existing wetwell and abandoning the drywell during the
next pump station rehabilitation.
With two new pumps adequately sized for the PWWF within the existing wetwell
(with lead pump rotating with every start), the station will have a maximum pump
cycle time of approximately 7 minutes (9 starts per hour), which should be within
the manufacturers recommendations for maximum pump cycling. Therefore, the
pump station wetwell is adequately sized to allow for proper pump cycling times.
Control functions at the Locust lift station are accomplished using an Allen-
Bradley MicroLogix PLC. The primary wetwell level sensor is a bubbler, which
controls the operation of the pumps. Additional high and low level float (two high
float switches, one for each pump) switches are used to operate the pumps in the
event of primary sensor failure, and sends an alarms through the communication
system when they are tripped. The level float switches are operated through the
pump station PLC. In the event of a PLC failure, there is no means to operate
the pumps. The float switches should be capable of operating the pumps and
sending alarms independently from the primary control system (PLC). This can
be achieved by adding a series of relays to the control panel.
Force Main Evaluation
The Locust lift station has a 4-inch PVC pipe force main that was constructed in
1977. The force main, once the pumps are upgraded to handle the PWWF, will
have a flow velocity of approximately 4.1 ft/s, which is within the recommended
range of velocities (between 2 and 10 ft/s).
The City indicated that there are no known issues with the force main. However,
due to its age, the condition should be further evaluated during the next pump
station rehabilitation.
The existing force main is 1085 feet long; therefore, in order to convey the
inflows in the event of a pump station failure a bypass pumping connection
City of Fontana - A4-3 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
should be installed on the force main. The bypass connection could be added
within the drywell just downstream of the station.
Flow Measurement and Monitoring
The Locust lift station does not currently have a flow meter. The station has a
relatively low inflow; therefore, flow monitoring at this station may not be
necessary unless the City is interested in the generation rates within the
sewershed and the operating rate of the lift station.
The existing force main is not exposed at a location where it is feasible to add a
flow meter; therefore, the addition of a valve vault would be required on the
discharge side of the pump station. The approximate cost of adding a flow meter
is included within the cost estimate section of this report.
Electrical Equipment and Motor Control Center Assessment
The existing incoming Southern California Edison (SCE) service (meter #SCE
3416-054188) is rated 100 amps, 120/240 volts, three phase. Electrical
equipment is housed inside of a weather rated equipment pedestal. The motor
controller uses electronic reduce voltage starters to control two 5 HP motors.
The existing service is adequate for the existing loads and has the capacity to
support up to two 10 HP motors. There are unsealed conduits from the wet well
into the equipment pedestal which is not California Electrical Code compliant.
That is, since the wet well is considered a hazardous location (Class 1 Division 1)
unsealed conduits allow gas to be transmitted into the equipment pedestal
requiring the equipment pedestal to be classified similarly. Furthermore, the
installation of a conduit body (an LB) to the side of the equipment will allow water
intrusion into the equipment pedestal.
The service feeds equipment in the station drywell. Equipment within the drywell
was not inspected due to confined space regulations.
Emergency/Backup Power Generation
Standby power at the Locust Lift Station is accomplished using a portable
generator via a permanently installed generator receptacle. The generator circuit
is sized to match the incoming service size and has a manual transfer switch
which insures the station is not being fed from two sources simultaneously. The
City has a dedicated 35 KW backup generator for this station that is kept at the
City corporation yard.
City of Fontana - A4-4 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
To start and operate the entire existing pumping load at this station continuously
for 48-hours (as recommended in the main report), we estimate a required fuel
supply of about 50 gallons of diesel fuel. Increasing the pump sizes to the
proposed two motors at 7.5 HP apiece could still be supported using the 35 KW
generator however the fuel consumption would increase to an estimated 75
gallons over the operating period. To maintain a reliable electrical system at the
lift station, the City would need to have the resources to move and install the
generator set and provide the fuel supply for continuous operation.
The time to overflow at the Locust pump station is 3.0 hours during the PDWF
and 2.2 hours during the PWWF. The City should have a response plan in place
to respond to this station, prior to an overflow, with a portable generator in the
event of a power failure.
Communication and Monitoring
Communication from the station is one way using a dialer connected to a
telephone land line to report alarm conditions to a central location. The dialer is
manufactured by RACO Verbatim VSS series. The communications system
sends a limited amount of information to the monitoring station; specifically, only
alarm signals are sent out. The existing telephone system does not receive
control signals from the monitoring station; therefore, the station can not be
operated remotely.
The existing communications system does not currently convey all of the
recommended alarm information to the monitoring station. The communications
system shall be capable of sending an alarm in the event of a communication
failure. This can be accomplished by installing a backup cellular alarm system
that sends an alarm in the event of a primary communication failure, or by
replacing the existing system with a radio telemetry system. A list of the
recommended and current pump station alarms are shown in Table 2. It may be
necessary to expand on the current system as the station is upgraded and
additional alarms and data is desired.
City of Fontana - A4-5 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 2: Current Station Alarms
Recommended Alarms
Locust Pump
Station Alarms
Communication Failure
Power Failure X
Drywell Entry
Control Panel Entry
Battery Low
Pump Failure
High Level X
Low Level
Dry Well Flooding
Structural and Seismic Assessment
The inspection of the Locust pump station was limited to the above ground
facilities. The pump station is in good overall condition. The electrical cabinet is
resting on a concrete slab in good condition and was anchored at each corner.
The visible portions of the steel drywell shaft was painted and did not indicate
signs of cracks or rust. The visible portions of the wetwell shaft was in good
condition with some concrete spalling just below the manhole frame steel.
Concrete spalling at manhole frame
Miscellaneous Site Improvements
Due to its close proximity to the street and associated vehicle traffic, bollards
should be placed around the electrical panel to protect it from possible collision.
According to NFPA 820, sewage drywells are Class 1 Division 2 Hazardous
Location and the electrical installation is required to meet this classification.
City of Fontana - A4-6 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Explosion proof equipment is required in Class 1 Division 2 hazardous locations.
Drywells and connected areas can be considered unclassified if they are
continuously ventilated with a forced in and forced out system that has a
minimum of six (6) air changes per hour. The existing drywell ventilation does
not meet these requirements; therefore, if the drywell is not abandoned, the
ventilation system should be replaced to meet the NFPA 820 requirements.
Pump Station Reliability
As previously discussed, the EPA and RWQCB have required cities to certify
their sanitary sewer pump stations for reliability. The reliability deficiencies and
the recommended corrective actions identified for the Locust lift station are listed
in Table 3.
Table 3: Locust Lift Station Reliability Deficiencies
Reliability Deficiency Corrective Action
Insufficient Pumping Capacity
Increase Pumping Capacity to Meet the PWWF
with One Pump
No Bypass Pumping Connection Install bypass pumping connection
Alarms Inoperable in the event of a Phone
Line Failure
Install backup cellular alarm system, or replace
with radio telemetry
Secondary Controller not Independent from
Primary
Modify existing controls so that backup floats are
independent from primary controller (PLC).
Cost Estimates / Recommended Improvements
The immediate recommended improvements and the estimated construction
costs for the Locust lift station are shown in Table 4.
Table 4: Locust Immediate Improvements Cost Estimate
Improvement Cost
Increase Pumping Capacity to Meet PWWF $30,000
Install Bypass Pumping Connection $15,000
Modify Alarm System $5,000
Modify Secondary Controller $2,000
Install Bollards Around Electrical Panel $6,000
Total $58,000
55% for Contingency, Admin., CM, Engr. $32,000
Total w/ Contingency $90,000
The cost estimate to perform a full rehabilitation on the Locust lift station is
shown in Table 5. This estimate assumes all items within the pump station will
be replaced, including those included in the immediate improvement list.
City of Fontana - A4-7 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 5: Locust Lift Station Cost Estimate
Item Size Make / Material Comments
Current
Replacement
Cost
Pumps and Motors
Pump and Motor #1 7.5 HP $13,000
Pump and Motor #2 7.5 HP $13,000
Subtotal $26,000
Electrical Equipment
Electrical Panel $15,000
SCADA System $5,000
Level Sensor Transducer w/ Backup Float $10,000
Backup Generator Replace Portable $30,000
Miscellaneous Wiring, coduit, etc. $10,000
Subtotal $70,000
Piping
Discharge Piping 4 inch Ductile Iron 60 LF @ $100/ LF $6,000
Fittings 4 inch Ductile Iron 6 EA @ $400 / EA $2,400
Check Valves 4 inch Ductile Iron (body) 2 EA @ $1000 / EA $2,000
Gate Valves (isolation) 4 inch Ductile Iron (body) 4 EA @ $1000 / EA $4,000
Bypass Pumping Connection $15,000
Subtotal $29,400
Miscellaneous Equipment
Flow Meter (optional) $6,000
Flow Meter Vault & Access Hatch (optional) $20,000
Replace wetwell top for rail mounted subersible pumps $15,000
Abandon drywell Remove top and fill with CDF $15,000
Wetwell Rehabilitation & Mods Structural Repair and Coating $10,000
Misc. Site Improvements Bollards, Sidewalk, Pavement, Etc $20,000
Bypass Pumping During Construction $20,000
Demolition & Disposal $10,000
Subtotal $116,000
Total $241,400
55% for Contingency, Admin., CM, Engr. $133,000
Total w/ Contingency $370,000
Notes:
1. Costs referenced to June 2011 Los Angeles Construction Cost Index (10051.30)
2. Costs include materials, labor, demolition and hauling
This estimate of construction cost is a professional opinion, based upon the engineer's experience with the design and
construction of similar projects. It is prepared only as a guide and is subject to change. Schaaf & Wheeler and its
subconsultants make no warranty, whether expressed or implied, that the actual costs will not vary from these estimated
costs, and assumes no liability for such variances.
25- Year Replacement Cost
City of Fontana - A4-8 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 1: Locust Pump Station
Photo 2: Control Panel
City of Fontana - A4-9 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 3: Wetwell
Photo 4: Drywell
City of Fontana - A5-1 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Industry Lift Station
The Industry Lift Station is located on the north side of Philadelphia Avenue, west
of Etiwanda Avenue and south of the cul-de-sac of Industry Avenue, as shown in
Figure 1. The pump station was originally constructed in 1988. Minor pump
station and force main improvements and upgrades have been performed since it
was originally constructed.
Figure 1: Industry Lift Station
Pump Station Inflows and Capacities
The Industry lift station receives sewage from the surrounding industrial areas
through a gravity sewer system. A summary of the pump station inflows and firm
capacity is shown in Table 1. The firm capacity (capacity of station with one
pump out of service) was determined by performing a drawdown test. The
Industry lift station does not have adequate capacity for the existing PWWF.
Table 1: Industry Inflows and Capacity
Total #
of
Pumps
Firm
Pumping
Capacity
(gpm)
Existing
PDWF
(gpm)
Existing
PWWF
(gpm)
3 383 352 472
Industry
Lift Station
City of Fontana - A5-2 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Pump Application and Control Strategy
The Industry lift station has three 10 hp pumps. The pump station firm capacity
is close to the PWWF; therefore, it may be possible to rebuild the existing pumps
or replace the impellers to meet the PWWF. However, the pumps are currently
23 years old, which is close to the recommended service life of sewage pumps.
Therefore, we recommend replacing the pumps. Based on Flygt pumps, we
estimate that new pumps adequately sized for the PWWF will have to be
approximately 7.5 hp each. Though these have less hp than the existing pumps,
the new would be more efficient and have a larger capacity. The City indicated
that the sewage is very corrosive and stainless steel impellers are required, this
should be considered when the station is being rehabilitated.
The existing pumps have variable frequency drives (VFD); however, they are
currently operated at a constant speed. We recommend analyzing the system
during the next pump station rehabilitation to determine if VFD’s are necessary.
With pumps adequately sized for the PWWF (with lead pump rotating with every
start), the station will have a maximum pump cycle time of approximately 11
minutes (6 starts per hour), which should be within the manufacturers
recommendations for maximum pump cycling. Therefore, the pump station
wetwell is adequately sized to allow for proper pump cycling times.
Control functions at the Industry pump station are accomplished using an Allen-
Bradley MicroLogix PLC. The station has two primary level sensors; a bubbler
and a pressure transducer. The sensor to be used for pump operation can be
selected on the PLC. Additional high and low level float switches are used to
operate the pumps in the event of primary sensor failure, and sends an alarms
through the SCADA system when they are tripped. The level float switches are
operated through the pump station PLC. In the event of a PLC failure, there is no
means to operate the pumps. The float switches should be capable of operating
the pumps and sending alarms independently from the primary control system
(PLC). This can be achieved by adding a series of relays to the control panel.
The current pump control logic operates the pumps on a lead-lag status and the
lead pump alternates between the three pumps. All three pumps will operate
during high water conditions, turning on at different levels.
City of Fontana - A5-3 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Force Main Evaluation
The Industry lift station has an 8-inch PVC pipe force main that was constructed
in 1988. The pump station currently primarily runs with one pump, which results
in a force main velocity of approximately 2.4 ft/s. This velocity is close to the
minimum recommended velocity; therefore, we recommend running all three
pumps on a daily basis (either manually or programmed with PLC) to flush the
force main.
When operating at the PWWF, the force main would have a flow velocity of
approximately 3.0 ft/s, which is within the recommended range of velocities
(between 2 and 10 ft/s).
The City indicated that the ductile iron fittings and valves within the drywell need
to be replaced annually due to the corrosivity of the sewage. The sewage should
be analyzed during the next pump station rehabilitation to determine the
corrosive constituents. A life cycle analysis on the pipe, fittings, valves, and
pump materials should be performed to determine if it is cost effective to replace
them with a material that is less susceptible to corrosion such as stainless steel.
The existing force main is 2460 feet long; therefore, in order to convey the
inflows in the event of a pump station failure a bypass pumping connection
should be installed on the force main. We recommend adding the bypass
pumping connection outside of the building for convenience; however, this would
require excavating the force main and adding a gate valve and bypass
connection. Alternatively the connection can be added within the drywell and
flexible hose can be routed from the wetwell to the connection when necessary.
Flow Measurement and Monitoring
The Industry lift station does not currently have a flow meter. There is not
sufficient space within the drywell to add a flow meter on the force main;
therefore, a valve vault on the force main would be required to add a flow meter.
The approximate cost to add the vault and flow meter is included in the cost
estimate section of this report.
Electrical Equipment and Motor Control Center Assessment
The existing incoming Southern California Edison (SCE) service (meter #SCE
Y728-1251 & Transformer #P5370031) is rated 100 amps, 480 volts, three
phase. The actual fuse rating of this station was not physically verified since we
were unable to remove the fuse holder. However, based upon the circuitry, the
City of Fontana - A5-4 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
fuse block maximum rating and the size of the motors operated a minimum of
100 amp service would be required.
Power distribution is accomplished using a tapped main feeder where the load
feeders tap the main feeder to supply power to the loads. Power and control to
the pumps is through a pump control panel containing three Toshiba variable
frequency drives (VFD). The VFD’s control three 10 HP pump motors at
constant speed (i.e. the VFD’s are essentially used as soft starts).
Emergency/Backup Power Generation
Standby power at the Industry Lift Station is accomplished using a permanently
installed 60 KW/75 KVA generator with an automatic transfer switch. Fuel for the
generator is provided from a skid mounted fuel tank. The fuel tank capacity is
estimated to be 161 gallons of diesel fuel (estimate base upon outside
dimensions of the tank of 36”x109”x9.5”). The fuel tank is reportedly not double
walled and there is no leak detection equipment in place. Furthermore, the
permanent location of the generator is approximately 28” from the pump station
building and about 28” from the block wall on the opposite side. This space
does not offer adequate working clearance between the generator and the
adjacent structures. The generator circuit is sized for a 100 amp circuit protection
and the generator has a 100/3 circuit breaker. The generator is sized for the
connected load and has the capacity to start and operate the entire station.
Decreasing the pump sizes to the proposed three motors at 7.5 HP apiece would
decrease the generator load. To start and operate the entire existing pumping
load at this station continuously for 48-hours (as recommended in the main
report), we estimate a required fuel supply of approximately 150 gallons of diesel
fuel. Similarly, with the new proposed load the fuel consumption is expected to
be about 120 gallons of diesel fuel over the operating period. To maintain a
reliable electrical system at the lift station, the City would need to have the
resources to provide the fuel supply noted for continuous operation.
The time to overflow at the Industry pump station is 1.1 hours during the PDWF
and 0.8 hours during the PWWF. In the event of a pump station failure, this is
the estimated time the City will have to respond before an overflow occurs. Once
the pump station reliability deficiencies are taken care of the likelihood of a
station failure is minimal because the station will have fully redundant
mechanical, electrical, and power systems.
City of Fontana - A5-5 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Communication and Monitoring
Communication from the station is one way using a dialer connected to a
telephone land line to report alarm conditions to a central location. The dialer is
manufactured by RACO Verbatim VSS series. This station uses a backup
wireless communications system and will transmit alarm signals if the dialer is
not operable. The communications system sends a limited amount of information
to the monitoring station; specifically, only alarm signals are sent out. The
existing telephone system does not receive control signals from the monitoring
station; therefore, the station can not be operated remotely. This system is
sufficient from a reliability standpoint.
The existing communication system does not currently convey all of the
recommended alarm information to the monitoring station. A list of the
recommended and current pump station alarms are shown in Table 2. It may be
necessary to expand on the current communication system as the station is
upgraded and additional alarms and data is desired.
Table 2: Current Station Alarms
Recommended Alarms
Industry Pump
Station Alarms
Communication Failure X
Power Failure X
Building Entry
Wetwell Entry
Battery Low
Pump Failure X
High Level X
Low Level X
Dry Well Flooding X
Structural and Seismic Assessment
The Industry pump station is in good overall condition. Surrounding the pump
station is a 6ft tall masonry block wall which retains approximately 4ft of soil. On
the west wall one of the masonry blocks was sticking out. The maintenance
personnel indicated this is due to the neighboring business backing their tractor
trailer trucks into the wall. It is recommended to install bollards on the
neighboring property to prevent further damage or accidental collapse of this
wall. The mortar cap shows some cracking, but the grout between the blocks is
in good condition. Review of the as-built drawings indicates that this block wall
was installed after preparation of the record drawings which specify fencing. It is
City of Fontana - A5-6 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
recommended that the wall plans and design be reviewed to determine if the wall
can adequately resist current Code specified seismic forces (ASCE 7-05 chapter
13). The emergency generator is supported by a steel frame which is anchored
to the concrete pad. Next to the generator there is a cabinet which has a
“Warning Flammable” label across both front doors which is currently
unanchored and resting on two pieces of wood. The feet of the cabinet are
currently sinking into the wood supports which could cause the cabinet to
become unbalanced and fall over. Without a positive connection between the
cabinet and the ground the cabinet is unstable during seismic events and should
be properly anchored for safety as required by Code (see ASCE 7-05 Chapter
13.4).
The pump station building is a wood framed structure with vertical wood
sheathing on the exterior walls, drywall on the inside of the walls, and a concrete
tile covered roof. The exterior rim boards show signs of deterioration at their
ends which should be replaced in the near future since these boards are
supporting the roof. Otherwise the wood roof is in good condition. There are
some signs of previous water leakage, however the roof looked dry even though
it was raining for much of the morning prior to arriving. The crane located on the
ground floor was installed after the building was constructed according to the as-
built drawings. In order to fit the large crane a section of two roof rafters were cut
and removed along with some drywall and a portion of the wall top plate has
been cut almost completely through. This section of roof is now unsupported and
should be off limits to personnel until mitigation is complete. This area should
either replace a portion of the cut rafters or provide adequate framing around the
opening to transfer the load. Due to the size of the opening, additional plywood
may be required to provide adequate roof strength. The wall top plate should
also be repaired to ensure proper transfer of gravity and seismic loads.
The concrete floor and concrete equipment pad show minor cracking. The
equipment cabinet is anchored; however it is unclear if the anchors extend
through the equipment pad down to the reinforced portion of the floor. Review of
the as-built drawings indicates the equipment pad has no reinforcement and is
not positively connected to the floor slab and should therefore not be relied upon
to resist the anchorage forces.
The visual inspection and review of the as-built drawings indicates this wood
framed structure may be lacking some of the typical elements necessary to resist
seismic forces. Only a detailed analysis of the structure can determine if it will
City of Fontana - A5-7 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
perform adequately under current code specified seismic forces (ASCE 7-05
Chapters 11&12). To the left of the doorway there is a small hole in the wall
which leads to an empty electrical box mounted on the wall inside. If this
opening is not needed it is recommended this hole be plugged to prevent water,
insects, and other items from entering the building.
The wetwell is in good condition with no visible cracks or root intrusion. Access
to the bottom of the dry well is down a metal spiral staircase. The staircase is in
good condition and anchored to the walls when possible. Near the top of the
staircase, a portion of the stair support is rusted along with the connection bolts.
This element should be cleaned and painted or replaced to ensure proper
support for the staircase. The catwalk suspended from the ceiling is in good
shape and no visible cracking was observed around the wall connection points.
At the bottom of the catwalk ladder, the grout pad under the anchor bolts is
spalling away beneath the ladder base. This grout pad should be repaired and/or
replaced to ensure proper bearing and anchorage of the ladder. During the
inspection the maintenance personnel indicated that it would be safer and more
convenient if they could access the suspended walkway directly from the spiral
staircase instead of going all the way to the bottom of the drywell and then
climbing the ladder. Due to the short distance between the catwalk and stairway
this modification should not be difficult and would likely improve worker safety.
The lower portion of the drywell walls show minor cracking. These cracks require
no current action but should be monitored. The concrete equipment pedestals
are in good condition with only minor cracking at the top caps.
Roof framing cut for crane installation
Bearing wall top plate cut for crane installation
City of Fontana - A5-8 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Perimeter wall damage due to truck impact
Unanchored storage cabinet
Deterioration at end of beams
Small hole in exterior wall
Stair support rust
Ladder grout pad deterioration
City of Fontana - A5-9 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Minor drywell cracking
Location of possible suspended catwalk access
Miscellaneous Site Improvements
The Industry lift station electrical room is located atop the station drywell and is
open to the drywell below. Since the electrical room is open to the drywell, it
takes on the same hazardous location classification as the drywell. According to
NFPA 820, sewage drywells are Class 1 Division 2 Hazardous Location and the
electrical installation is required to meet this classification. Explosion proof
equipment is required in Class 1 Division 2 hazardous locations. Drywells and
connected areas can be considered unclassified if they are continuously
ventilated with a forced in and forced out system that has a minimum of six (6) air
changes per hour.
The existing ventilation at the Industry lift station is a forced air in system that is
controlled by a thermostat and a manual switch, and therefore, does not meet the
requirements for an unclassified area. Furthermore, the capacity of the
ventilation system is unknown and, therefore, it is uncertain if the ventilation
system is capable of the required air changes in the drywell and the electrical
room. We recommend installing a new ventilation system that meets these
requirements so that the drywell and control room is “unclassified” and explosion
proof equipment is not required.
City of Fontana - A5-10 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
There is a minor leak at the drywell force main penetration. The leak appears to
be groundwater. We recommend confirming that the leak is resulting from
groundwater and not from a leaking force main. If the leak is from groundwater,
we recommend stuffing ramnek joint sealant, or another sealant material into the
space between the force main and the drywell penetration.
The City’s O&M staff indicated that they would like to be able to access the
elevated platform within the drywell from the spiral staircase. We recommend
modifying the platform and stairwell to allow access as discussed in the structural
section of this report.
Pump Station Reliability
As previously discussed, the EPA and RWQCB have required cities to certify
their sanitary sewer pump stations for reliability. The reliability deficiencies and
recommended corrective actions identified for the Industry lift station are listed in
Table 3.
Table 3: Industry Lift Station Reliability Deficiencies
Reliability Deficiency Corrective Action
Insufficient Pumping Capacity
Increase Pumping Capacity to Meet the PWWF
with Largest Pump Out of Service
No Bypass Pumping Connection Install bypass pumping connection
Secondary Controller not Independent from
Primary
Modify existing controls so that backup floats are
independent from primary controller (PLC).
Cost Estimates / Recommended Improvements
The immediate recommended improvements and the estimated construction
costs for the Industry lift station are shown in Table 4.
Table 4: Industry Immediate Improvements Cost Estimate
Improvement Cost
Increase Pumping Capacity to Meet PWWF $50,000
Replace Ventilation System $20,000
Modify Secondary Controller $2,000
Install Bypass Pumping Connection $5,000
Modify Building Framing Adjacent to Hoist $5,000
Total $82,000
55% for Contingency, Admin., CM, Engr. $45,000
Total w/ Contingency $127,000
City of Fontana - A5-11 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
The cost estimate to perform a full rehabilitation on the Industry lift station is
shown in Table 5. This estimate assumes all items within the pump station will
be replaced, including those included in the immediate improvement list. Please
note that this estimate is based on standard pipe and valve materials. If it is
determined to be more cost effective to use stainless steel, or other non-standard
materials, the construction cost could be greatly affected.
City of Fontana - A5-12 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Table 5: Industry Lift Station Cost Estimate
Item Size Make / Material Comments
Current
Replacement
Cost
Pumps and Motors
Pump and Motor #1 7.5 HP Flygt $13,000
Pump and Motor #2 7.5 HP Flygt $13,000
Pump and Motor #3 7.5 HP Flygt $13,000
Subtotal $39,000
Electrical Equipment
Electrical Panel $20,000
SCADA System (Site Only) RTU & Assoicated Equipment $5,000
Level Sensor Transducer w/ Backup Float $10,000
Backup Generator $40,000
Miscellaneous Wiring, coduit, etc. $15,000
Subtotal $90,000
Piping
Discharge Piping 6 inch Ductile Iron 100 LF @ $100/ LF $10,000
Fittings 6 inch Ductile Iron 9 EA @ $1000 / EA $9,000
Check Valves 6 inch Ductile Iron (body) 3 EA @ $1500 / EA $4,500
Gate Valves (isolation) 6 inch Ductile Iron (body) 6 EA @ $1500 / EA $9,000
Bypass Pumping Connection Gate Valve and Camlock $5,000
Subtotal $37,500
Miscellaneous Equipment
Flow Meter (optional) $7,000
Flow Meter Vault & Access Hatch (optional) $20,000
Wet Well Rehabilitation & Mods Structural Repair and Coating $30,000
Building Rehabilitation & Mods $40,000
Ventilation System $20,000
Misc. Site Improvements Pavement, Fencing, etc. $25,000
Bypass Pumping $5,000
Demolition & Disposal $30,000
Subtotal $177,000
Total $343,500
55% for Contingency, Admin., CM, Engr. $189,000
Total w/ Contingency $530,000
Notes:
1. Costs referenced to June 2011 Los Angeles Construction Cost Index (10051.30)
2. Costs include materials, labor, demolition and hauling
This estimate of construction cost is a professional opinion, based upon the engineer's experience with the design and
construction of similar projects. It is prepared only as a guide and is subject to change. Schaaf & Wheeler and its
subconsultants make no warranty, whether expressed or implied, that the actual costs will not vary from these estimated
costs, and assumes no liability for such variances.
25- Year Replacement Cost
City of Fontana - A5-13 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 1: Industry Pump Station
Photo 2: Control and Motor Room
City of Fontana - A5-14 - Schaaf & Wheeler
Sanitary Sewer Pump Station Eval. August 9, 2011
Photo 3: Wetwell
Photo 4: Drywell