HomeMy WebLinkAboutSupplemental - Question from Robert GoldbergGloria Harper
From:
Robert Goldberg <rgoldberg @live.com>
Sent:
Sunday, February 24, 2019 10:21 PM
To:
Joe Kalmick; Schelly; Mike Varipapa; Sandra Massa- Lavitt; Thomas Moore
Cc:
Gloria Harper; Jill Ingram; Steve Myrter; Community Media Corporation
Subject:
Question for Council meeting 2/25/19
Attachments:
Sewer MP.Pump St #35.pdf
Dear Council and Staff,
I just have one pre- meeting question for this Monday night on Item G regarding the Sewer Pump Station AKM
Contract:
This contract is to prepare bid -ready documents for the construction of a bypass_ pumping system and
replacement of piping and valves in the drywell of Pump Station #35. However, this $500,000 project does not
appear to be described or included in the Sewer Master Plan (see attached sub - section) that was just adopted
by Council in Jun 2018.
Why is this project not in the MP?
Thank you,
Robert Goldberg
station, sewage is pumped through a 16-
inch diameter force main to the Seal
Beach Boulevard Trunk line, which
terminates at OCSD's Seal Beach Pump
Station located at the intersection of Seal
Beach Boulevard and Westminster
Avenue. Pump Station No. 35 was
constructed in 1973 as part of a
comprehensive program that eliminated
the City's wastewater treatment facility.
The project redirected flows from the
southwest quadrant of the City, where
the treatment plant was located, to the
southeast quadrant of the City where the
pump station was constructed. Pump
Station No. 35 was upgraded in 2006
and 2007, with most of the mechanical
equipment replaced.
PUMP STATIONS
Photograph 7 -14
Pump Station 35
Pump Station Housing
The upgraded facility incorporates three dry well pumps (Photograph 7 -15), all rated at 1500 gpm. All three are
connected to a variable frequency drive (VFD) and an electric motor. Two of the three pumps are backed up
by a natural gas engine, which can operate the pumps in the event of a power outage (Photograph 7 -16).
The dry well has stairway access from the building above, which houses the electric motors, natural gas
engines, and electrical switchgear. There is an overhead crane in the building which can be positioned over a
hatch in the floor to remove the pumps below. The maintenance staff has noted that the crane and ceiling
height are too low to remove the motors and drives.
Photograph 7 -15
Pump Station 35
Dry Well and Pumps
Photograph 7 -16
Pump Station 35
7 -19 City of Seal Beach
R:VRPTSISeaI BeacMSewer System Master Plan (16)IFinal ReportlFinal Report - Feb 2018.docx Sewer Master Plan 2018
J
PUMP STATIONS
The station's dry well is a 19'x 20'x 21' deep structure which houses the pumps, valves, discharge piping, and
ventilation equipment. The pumps are connected by long shafts to the motors and drives above. The City has
reported problems maintaining these shafts. Bearings are located 15 feet from the floor and are difficult to
replace while on a ladder.
Wastewater enters the wet well through a screening structure with a main channel and a bypass channel. The
wet well varies from 4 -feet to 6 -feet wide and extends the length of the dry well, or 20 feet. It is hoppered to
prevent solids from settling in the corners.
The floor elevation at the pump station motor /engine room is 7.1 ft. amsl. The dry well floor elevation is -13.9
ft, and the wet well invert elevation is -12.9 feet.
Flows
Pump Station No. 35 collects and pumps wastewater generated from the Bridgeport, Marina Hill North, Marina
Hill South, Old Town areas, and the US Naval Weapons Station. On average, the station pumps 0.7 million
gallons per day (448 gpm), including dry weather infiltration. The existing peak dry and wet weather flows are
estimated at 829 gpm and 1119 gpm, respectively.
Collection System
The area tributary to Pump Station No. 35
is large (roughly 750 acres) and includes
three (3) pump stations. Flows are
generally collected in the 24 -inch Electric
Avenue Trunk Sewer, which turns
northeast along Seal Beach Boulevard,
and then east into the pump station's wet
well. A 12 -inch VCP gravity sewer from
the Naval Weapons Station extends to a
manhole located 30 feet southwest of the
pump station, where the flow is measured.
The 12 -inch sewer continues 7 feet west,
then 50 feet north, confluencing with the
24 -inch diameter sewer at a manhole just
to the west of the wet well.
Figure 7-6 shows the pump station's
tributary area.
Disposal System
Figure 7 -6: Pump Station No.35 Service Area
Sewage collected at Pump Station No. 35 is pumped through 4,150 feet of 16 -inch ductile -iron and a short
section of PVC force main in Seal Beach Boulevard to the 24 -inch VCP Seal Beach Boulevard Trunk Sewer,
just south of Catalina Avenue. The 24 -inch trunk sewer extends north in Seal Beach Boulevard to OCSD's
Seal Beach Pump Station for further conveyance to the OCSD system.
7 -20 City of Seal Beach
R:IRPTSISeal BeachlSewer System Master Plan (16 J1Final ReportlFinal Report - Feb 2018. docx Sewer Master Plan 2018
PUMP STATIONS
Pumping Equipment
The existing pumping equipment is listed in Table 7-8. All equipment is located in the dry well and
superstructure above.
The lead pump is set to start at a wet well sewage elevation of -6.4 feet (6.5 feet above the wet well invert), and
stop at -8.4 feet. The lag pump is set to start at a wet well sewage elevation of -5.9 feet (7.0 feet above the wet
well invert), and stop at -7.9 feet.
Table 7-8
Pump Station No. 35
Pump Station Name
Pump Station No. 35
Location
Seal Beach Blvd.
& Electric Ave
Plan Identification
Interceptor Sewers and Pumping Station
S- 0073 -A thru S- 0109 -A
Construction Date
2006
Pump Information
Pump No.
1
2
3
Type of Pump
Wemco
Hidrostal Model
H8K -H -H4W
10x8
Wemco
Hidrostal Model
H8K -H -H4W
10x8
Wemco
Hidrostal Model
H8K -H -H4W
10x8
Capacity (gpm)
150012940
1500/2940
1500/2940
Head (ft)
97/67
97/67
97/67
HP
100
I.S. Motor
100
I.S. Motor
100
I.S. Motor
RPM
1210
1210
1210
Voltage
480 V
480 V
480 V
Number of Phases
3
3
3
Impeller Diameter (in)
Force Main Information
Start Point
Pump Station No. 35
Wet Well Invert (ft)
-12.9
End Point
Manhole connecting to 24" VCP gravity sewer in
Seal Beach Boulevard south of Catalina Avenue
End Point Invert (ft)
41.1
Size (in)
16
Material
DIP /PVC
Length (ft)i
4150
7 -21 city of Sea/ Beach
R.IRPTSISeal SeachlSewer System Master Plan(16)IFinal ReportlFinal Report -Feb 2018.docx Sewer Master Plan 2018
PUMP STATIONS
Deficiencies
While the overall condition of the station is good, the following concerns exist:
1. It is difficult to maintain the long drive shafts connecting the pumps to the motors because the
intermediate bearings are high and they are difficult to access. Close- coupled motors would make
maintenance easier. However, this would require replacing the two natural gas engines with a standby
generator so that the pump station can be operated in case of a commercial power outage.
2. The City has been primarily using Pump No.3, which is the pump without a gas engine drive. The
engines for Pumps No.1 and 2 are old. All three pumps need to be operated regularly to ascertain that
they will be available when needed. Due to air quality regulations, it will be difficult to permit new engine
drivers that would operate regularly.
1 The pump station experiences grease problems.
4. The single force main is over 40 years old
Recommended Improvements
The following recommendations are provided to keep this very important facility in operation in accordance with
the City's criteria:
1. Construct a parallel force main
2. Increase the wet well cleaning frequency from once every three months to every month to maintain the
wet well free of grease accumulation
3. Prepare for replacement of the pumps with close coupled electric motor driven units in the next 10
years. Construct a natural gas engine generator to power the entire facility in case of a commercial
power outage. Replace the electrical and control system at that time.
4. Increase public education as part of the City's Fats, Oils and Grease Program to reduce grease tributary
to the pump station.
7 -22 City of Sea/ Beach
R:IRPTSISeal BeachlSewer System Master Plan (16)lFinal ReportlFinal Report - Feb 2018.docx Sewer Master Plan 2018