(a) 
Vitrified clay pipe (VCP) may be used:
(1) 
On all gravity public collector sewers and building sewers (laterals).
(2) 
Where pipe cover is greater than four feet in all areas.
(3) 
Where pipe cover is greater than two feet in areas not subject to vehicular loadings.
(b) 
Ductile iron pipe (DIP) lined with Protecto 401 ceramic epoxy coating must be used:
(1) 
Where pipe cover is less than four feet in areas subject to vehicular loadings.
(2) 
Where pipe cover is less than two feet in areas not subject to vehicular loadings.
(3) 
When pipe slope is greater than 20 percent or upon written authorization by the District.
(4) 
In special circumstances, as required by the District.
(c) 
High density polyethylene (HDPE – SDR 17), color black (with gray lining) or gray may be used:
(1) 
On building sewers subject to District Code and Specifications.
(2) 
On all residential force main systems.
(3) 
Where pipe cover for building sewers is greater than four feet in areas subject to vehicular loadings.
(4) 
Where pipe cover for building sewers is greater than two feet in areas not subject to vehicular loadings.
(Added, § 1, Ord. 169, 05-03-2016; amended, § 1, Ord. 174, 11-07-2017)
(a) 
Eight-inch diameter minimum for public (District maintained) main sewers.
(b) 
Four-inch diameter minimum for individual gravity building sewer (lateral).
(c) 
Two-inch diameter minimum for conventional pump residential force main system.
(d) 
One-and-one-quarter-inch diameter minimum for grinder pump residential force main system.
(Added, § 1, Ord. 169, 05-03-2016)
The following pipe slopes must be maintained:
Main Diameter (inches)
Minimum Slope (%)
8
0.34
12
0.20
15
0.15
18
0.12
21
0.10
24
0.08
27
0.07
30
0.06
(a) 
The maximum pipe slope of 20 percent shall not be exceeded without specific written authorization by the District.
(b) 
The minimum slope on sewer mains serving less than seven single-family dwelling units shall not be less than 0.7 percent. Every effort shall be made to provide the highest velocity possible.
(Added, § 1, Ord. 169, 05-03-2016; amended, § 1, Ord. 174, 11-07-2017; § 1, Ord. 183, 09-03-2019)
Use straight grade between maintenance holes. Curvilinear alignment (vertical and horizontal, or in combination) to be minimum 300-foot radius, accomplished by deflection at pipe joints, at one half of pipe manufacturer’s allowable deflection at each pipe joint. Locate sewers on street centerline for new developments and in existing streets where possible, except where specified otherwise by Alameda County Public Works Department.
Maintenance holes shall be placed:
(a) 
At 300-foot nominal spacing;
(b) 
At all junctions of main sewers;
(c) 
At all ends of sewer mains, except stubs for future extensions with no lateral connections;
(d) 
At all changes of pipe size (match crowns at change of pipe size);
(e) 
Or as otherwise required by the District.
Drop maintenance holes are not permitted on new subdivision design or at connection of a new main line extension to the existing system unless authorized by CVSan.
Where the sewer does not change size or direction at a maintenance hole, the maintenance hole base should have a through fall of 0.1 feet..
Calculate velocity head loss at all changes of direction in maintenance hole:
Loss
V2
x
Deflection
(0.25 feet minimum)
2g
(90o)
(Added, § 1, Ord. 169, 05-03-2016; amended, § 1, Ord. 183, 09-03-2019; § 1, Ord. 184, 04-07-2020; § 1, Ord. 204, 05-06-2025)
(a) 
General Requirements.
(1) 
These requirements shall apply to any sewage pump station that is to be operated by the Castro Valley Sanitary District.
(2) 
All pumping systems shall be designed by a registered civil or mechanical engineer in the State of California and shall be sealed and signed by the registered engineer in charge of design.
(3) 
All design and construction shall be done in conformance with the general requirements of Cal/OSHA, current applicable electrical, plumbing, and building codes, and District requirements.
(4) 
All equipment and accessories shall be industry standard manufactured items and those coming into contact with sewage shall be specifically manufactured for sewage use.
(5) 
Prior to construction, the contractor or engineer shall submit detailed design information to the District for review and approval. The District may request additional information, require changes to agree with the District’s specifications, or agree that the submitted information conforms to the District’s requirements. At a minimum, the following items shall be submitted to the District for review:
(A) 
Construction Drawings.
(i) 
General drawings including location and vicinity maps, an index to drawings, legends, and a site plan.
(ii) 
Civil and mechanical drawings showing plan and profile drawings of the station, proposed pumping system, force main alignment, building gravity sewer (if applicable), trenching and shoring details (if necessary), demolition details, and pavement restoration.
(iii) 
Structural drawings showing concrete reinforcement and building design details (if applicable).
(iv) 
Electrical drawings showing power distribution schematics, single-line diagram, panel layouts, variable frequency drive (VFD) schematics (if applicable), motor control center (MCC) and control panel elevations, electrical schedules, and lighting plans.
(v) 
Process and instrumentation diagrams that show process controls and alarms.
(B) 
A specification package that includes front end (Division 0 and Division 1) specifications as well as complete technical specifications (Divisions 2 through 17).
(C) 
Calculations Package.
(i) 
Pump curves showing flow rate, head, power, efficiency, and net positive suction head required. For pumps that are being provided with VFDs, submit curves showing the pump operation at full speed and at reduced speeds.
(ii) 
System curves at both low-water level and high-water level. The pump curves shall be plotted with the system curves to demonstrate the design operating points.
(iii) 
Buoyancy calculations for wet wells, sumps, maintenance holes, and vaults.
(iv) 
Structural design calculations (if necessary).
(v) 
Electrical design calculations.
(b) 
Design Requirements.
(1) 
Pumps.
(A) 
All pump stations shall be provided with a redundant standby pump designed to function independently in case of failure of the primary duty pump. The standby pump shall be sized to match the largest duty pump at the station.
(B) 
The pump station controls shall be designed to automatically rotate the lead-lag designations of the pumps on each operating cycle so that the pumps experience roughly equal run times.
(C) 
An alarm shall be generated if any pump fails to run when it is called to start.
(D) 
The system controls shall be designed such that the lag pump is called to run in the event that the lead pump is unable to maintain the proper level. This condition shall activate an alarm.
(E) 
Pumps shall be the submersible centrifugal type and shall be provided with nonclog impellers capable of passing a two-inch sphere. The pump shall be a Flygt N-pump or equal, subject to approval by the District.
(F) 
Pumps shall be equipped with shark tooth accessory for ragging.
(2) 
Motors.
(A) 
Pump motors shall be minimum 10 horse power (HP) and shall be nonoverloading for the entire full-speed pump operating curve.
(B) 
Pump motors shall be submersible, designed for operation in a Class 1, Division 1, Group D explosion-proof atmosphere and certified as such by Factory Mutual, and Underwriters Laboratories (UL) listed.
(C) 
For applications which require the use of VFDs, the motors shall be inverter duty.
(D) 
Motors shall be provided with moisture sensors in the inner-seal chamber to detect moisture and warn of impending outer-seal failure.
(3) 
Wet Well.
(A) 
The submersible pumps shall be mounted in a reinforced concrete wet well. The wet well shall be designed in accordance with Hydraulic Institute standards for pump intake structures for solids-bearing liquids.
(B) 
The interior concrete surfaces of the wet well shall be coated with a multi-component resin-based mortar lining system specifically designed to protect the concrete surfaces from chemical attack.
(C) 
The wet well shall be provided with a flush floor hatch (or multiple hatches) to allow for installation and removal of the pumps.
(D) 
A two-inch or larger diameter vent is required; the vent shall extend above the pump station slab and have a return bend at the top of the vent.
(4) 
Emergency Overflow Sump.
(A) 
Each wet well shall be provided with a high-level emergency overflow sump. The sump shall be sized to provide a minimum of 24 hours of storage at the average dry weather flow rate of the pump station.
(B) 
The tank shall be filament-wound fiberglass with minimum one-quarter-inch structural wall thickness. The interior surface of the tank shall be provided with a minimum one-tenth-inch-thick resin-based corrosion barrier.
(C) 
The emergency overflow sump shall be connected to the wet well by means of a pipe with minimum diameter of six inches. No valves, fittings, or bends shall be permitted in this connecting pipe.
(D) 
The invert of the connecting pipe shall be no less than two feet below the top of the pump station slab, and no less than eight inches above the high-water level in the wet well.
(E) 
The overflow sump shall be provided with a flush floor hatch (or multiple hatches).
(F) 
In areas with high groundwater levels, the sump shall be provided with an anti-flotation flange.
(5) 
Controls and Communications.
(A) 
Each pump station shall be provided with a programmable logic controller (PLC) housed in a control panel. The PLC shall be capable of recording wet well level and flow data.
(B) 
The control panel shall be mounted in a convenient and accessible location and shall have a National Electrical Manufacturers Association (NEMA) rating that is appropriate for the location and environmental conditions. Outdoor panels shall be minimum NEMA 4X; indoor panels shall be minimum NEMA 1. The panel shall be provided with a large touch screen monitor and an uninterruptible power supply (UPS) battery backup system.
(C) 
Where necessary to prevent excessive on/off cycling of the pumps, or as directed by the District, the pumps shall be supplied with VFDs. Any pump not provided with a VFD shall be provided with a soft starter.
(D) 
The primary level controller shall be an ultrasonic level sensor installed in a stilling well. The stilling well shall be polyvinyl chloride (PVC) pipe, minimum eight inches in diameter, and shall have a vent hole located near the top of the pipe to allow the fluid to move up and down freely.
(E) 
Each pump station wet well shall be provided with float switches that serve as the emergency backup level sensors.
(F) 
The pump level controls shall be wired directly and independently to terminals within the control panel.
(G) 
The pump station shall be provided with a verbatim auto dialer with a minimum of 20 channels for alarms. The following alarms shall be provided, at minimum:
(i) 
Pump failure.
(ii) 
High wet well level.
(iii) 
Low wet well level.
(iv) 
Motor moisture.
(v) 
Generator failure.
(vi) 
Control panel intrusion alarm.
(vii) 
Building intrusion alarm (where applicable).
(viii) 
Access gate intrusion alarm (where applicable).
(6) 
Electrical.
(A) 
All electrical wiring and installed cabling, conduit, and controls shall meet National Electric Code (NEC) Class 1, Division 2 requirements.
(B) 
All electrical work shall conform to the requirements of Alameda County, and/or the District, whichever in the opinion of the authorized District representative is the most stringent.
(C) 
Power to the pump station shall be three phase, 60 Hz.
(D) 
Level controls and all alarm system circuits shall be listed by a Nationally Recognized Testing Laboratory (NRTL) such as Underwriters Laboratories Inc. (UL) or Canadian Standards Association (CSA) as intrinsically safe.
(E) 
Separate conduits shall be run between the sump and the control panel for the level switch wiring and the motor power wiring.
(F) 
Each pump and the level control/alarm system shall be on separate electrical circuit breakers.
(G) 
Power requirements shall be as recommended and approved by Pacific Gas and Electric Company.
(H) 
Controls and communications shall be supervisory control and data acquisition (SCADA) capable.
(7) 
Emergency Generator.
(A) 
Each station shall be provided with a natural-gas-powered emergency standby generator and automatic transfer switch.
(B) 
The generator shall be capable of providing power to maintain all station functions in the event that the main electrical power supply is interrupted for any reason.
(C) 
The generator shall be housed inside a concrete masonry unit (CMU) building. The building shall be sized to provide adequate clearance around the generator for all maintenance activities. The building shall also include at least 150 square feet of space for storage of equipment and supplies.
(8) 
Pump Station Piping and Valves.
(A) 
All exposed valves, piping, and fittings shall be flanged ductile iron pipe (DIP). All buried piping shall be restrained mechanical joint DIP or SDR-17 high-density polyethylene (HDPE).
(B) 
The discharge of each pump shall be provided with a minimum one-half-inch air relief valve (ARV), check valve, and isolation gate valve. The drain from the ARV shall be routed into the wet well.
(C) 
All below-grade valves shall be installed in precast concrete vaults. The vaults shall be provided with a flush floor hatch (or multiple hatches) to allow for installation and service of the valves.
(D) 
Each station shall have bypass piping that includes an isolation gate valve and a check valve. The point of connection for the bypass shall be a quick-release male camlock-type connection, minimum three inches in diameter. The bypass piping, valves, and connection shall be located in a precast valve vault with a flush floor hatch (or hatches).
(E) 
The force main shall be installed with a tracer wire per District standards.
(9) 
Vaults and Hatches.
(A) 
All vaults shall be precast reinforced concrete and shall be sized to provide adequate working clearance and access to all nuts and bolts.
(B) 
All vaults used in sewer service shall have drain lines that drain back into the pump station wet well.
(C) 
Hatches shall be anodized aluminum or galvanized steel and shall seal with a gasket to reduce odors.
(D) 
Hatches shall be designed for dead and live loads; in areas that experience vehicle traffic, hatches shall be designed to support American Association of State Highway and Transportation Officials (AASHTO) H-20 wheel loads.
(E) 
Hatches shall be provided with fall protection where required by Occupational Safety and Health Administration (OSHA) regulations.
(F) 
Hatches and vaults shall be confined spaced compatible and accessible via Vac-Con combo unit.
(10) 
Force Main.
(A) 
The force main shall be sized for fluid velocity in the force main to be three to eight feet per second.
(B) 
The force main material shall be SDR-17 HDPE or ductile iron pipe.
(C) 
The pressure force main shall conform to the District’s Standard Specifications and shall meet the District’s depth and bedding requirements for building sewers.
(D) 
Force mains shall be provided with access points to allow for cleaning and inspection. The access points shall consist of a wye with a blind flange, housed inside a concrete maintenance hole. The wye and blind flange shall be minimum eight inches diameter. On force mains larger than eight inches, the wye and blind flange shall be sized to match the force main.
(11) 
Access and Maintenance.
(A) 
Each pump station shall have adequate space for access by maintenance vehicles.
(B) 
Unless otherwise directed by the District, each pump station shall be surrounded by a fence or wall with a secure access gate. The gate shall be large enough to allow for maintenance vehicle access.
(C) 
Each pump station shall be provided with a means for removal of all pumps and valves; this could be a monorail with an electric hoist, a jib crane, a portable rolling floor crane, or a portable davit crane. If a portable davit crane is to be used, a pedestal base permanently anchored to the pump station slab shall be provided. Multiple pedestal bases may be required to allow for removal of all equipment.
(12) 
Potable Water Supply.
(A) 
Each pump station shall be provided with a potable water supply for cleaning and maintenance purposes.
(B) 
The water line shall be minimum one inch and shall be provided with a reduced pressure zone backflow preventer and associated valves and test ports.
(C) 
Each station shall be provided with a minimum of two hose bibs or post hydrants; hose bibs and post hydrants shall be minimum three-quarters inch.
(Added, § 1, Ord. 174, 11-07-2017; amended, § 1, Ord. 204, 05-06-2025)