33 32 17 SUBMERSIBLE UTILITY WASTEWATER PUMPING STATION
SECTION 1 - GENERAL
1.1 SUMMARY
A. This Section specifies furnishing and installing a fully operational and complete submersible pump station as detailed on the drawings and specifications, including all labor, materials, site grading, structures, excavation, sheeting, backfill, reinforced concrete, masonry, carpentry, yard piping, equipment piping, miscellaneous piping, equipment, electrical work, controls, incidental painting, and all other items or material and work required to construct structures and furnish and install equipment for a complete installation.
B. The intent and purpose of these specifications is to require a complete and satisfactory installation in every respect and any defects in material or workmanship shall be cause for the replacement and correction of such defect as directed by the Utility.
1.2 QUALITY ASSURANCE
A. Wastewater pump stations shall be designed and permitted (at a minimum) in accordance with applicable State permitting requirements.
B. Prior to construction of the facilities, the Contractor shall be responsible for coordinating all electrical work with local electric utility or Base Privatized Electrical provider.
C. Electrical equipment, materials and workmanship shall comply with all applicable codes, safety and fire law regulations at the location of the work and shall conform to applicable codes and standards of the organizations listed below:
1. Utility requirements.
2. National Electrical Motors and Generators
a. NEMA ICS2 Industrial Control Devices, Controllers and Accessories.
b. NEMA MG1 Motors and Generators Standards listed above refer to the latest revision.
3. Submersible Wastewater Pump Association – SWPA Submersible Sewage Pumping Systems Handbook.
4. Department of Defense Unified Facilities Code – Sanitary and Industrial Wastewater Collection: Pumping Stations and Force Mains. DOD_UFC 3-240-08FA
5. National Electrical Code (NEC)
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Revision Date: 12/12/2018 D. All equipment and materials shall be new and shall bear the manufacturers name and trade name.
E. In cases where the standard has been established for the particular material, the material shall be so labeled.
F. The equipment to be furnished shall essentially be the standard product of a manufacturer regularly engaged in the production of the required type of equipment for this type of work and shall be the manufacturers latest approved design.
G. Equipment and material shall be suitably delivered and stored, and shall be readily accessible for inspection. All items subject to moisture damage shall be stored in dry spaces. All material and equipment shall be protected against dirt, dust, water and chemical or mechanical injury, vandalism and theft.
1.3 SUBMITTALS
A. Product Data: Include rated capacities, operating characteristics, furnished specialties, and accessories.
B. Shop drawings shall be provided for all fabrication and installation details for each packaged sewage pumping station. Equipment assemblies shall be detailed to indicate dimensions; shipping, installed, and operating weights; loads; required clearances; method of field assembly; components; electrical characteristics; and location and size of each field connection.
C. Shop drawings and manufacturer’s product data shall be submitted to the Utility for the following items at a minimum:
1. Pumps 2. Wetwell 3. Generator 4. Drives 5. Valves 6. Controls 7. Rainhood 8. Valve Vault 9. Wiring Diagrams: Power, signal, and control wiring. 10. SCADA P&ID and wiring diagrams 11. SCADA equipment including RTU and antenna 12. All control panels and enclosures 13. Jib crane 14. Access Hatches 15. Wetwell 16. Valve vault sump pump 17. Paint and coatings to be used on the project
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Revision Date: 10/04/2019 D. Certificates of Compliance shall be submitted to the Utility for the following
1. Pumps 2. Drives 3. Controls
E. Operating & Maintenance and Service Manuals
1. The Contractor shall furnish one digital copy on a USB Flash Drive of an Operating & Maintenance and Service manual covering all of the equipment furnished for the wastewater pumping station.
2. The manual shall contain complete descriptions of each item of equipment and a complete parts list showing factory parts numbers. It shall also contain complete operating and service instructions and shall be tabbed and indexed for easy use. Manuals shall be submitted within 60 days after final review of shop drawings.
SECTION 2 – MATERIALS
2.1 GENERAL
A. The Utility will consider a factory constructed pumping station in lieu of a site constructed pumping station. The factory constructed pumping station shall generally meet all of the requirements of the specifications including this Section 33 32 17 Submersible Utility Wastewater Pumping Station, the Electrical Sections – Division 26 of the specifications, Section 33 32 50 Emergency Generators and Backup Pumping Systems, and any other Section of the specification that is related to the Pumping Station construction. The contractor is solely responsible for determining that the proposed factory constructed pumping station is in conformance with all project requirements. The Utility may allow deviations from the project requirements if the contractor specifically requests deviations from the project requirements, and those deviations are specifically approved by the Utility.
B. The contractor shall furnish, take possession of when delivered, and install the pumping station equipment where shown on the drawings, complete with all incidental and appurtenances required for a complete, finished and fully operational installation.
C. All equipment components shall be adequately sized to carry all loads and stresses occurring during fabrication and erection and resulting from normal and emergency operation in the installation shown on the drawings and under the conditions specified and/or implied.
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Revision Date: 10/04/2019 2.2 SUBMERSIBLE PUMPS & MOTORS
A. Pumps, motors, and controls shall be as specified herein and as indicated on the drawings:
1. Type: Vertical submersible centrifugal non-clog, typically 2 required (Duplex System). See plans to determine if more than 2 pumps are required. Grinder pumps may be acceptable for some installations as approved by the Utility or shown on the plans.
2. Capacity: Per Plan Data or attached Data Sheet
3. Minimum sphere size: 3-inch
4. Efficiency at design point: Per Plan Data or attached Data Sheet
5. NPSHr at design point: Per Plan Data or attached Data Sheet
6. Motor performance requirements:
a. Motor horsepower: Per Plan Data or attached Data Sheet
b. Motor speed: Per Plan Data or attached Data Sheet
c. Nominal power supply: Per Plan Data or attached Data Sheet
d. Maximum current: Per Plan Data or attached Data Sheet
e. Minimum power factor at full load: Per Plan Data or attached Data Sheet
f. Minimum efficiency at full load: Per Plan Data or attached Data Sheet
g. Minimum service factor: 1.15
B. Submersible Pumps
1. Pumps shall be submersible, centrifugal non-clog capable of passing solids as specified with hydraulic sealing diaphragms, pump mounting plates and base elbows with bottom rail supports, stainless steel upper rail supports, stainless steel lifting cable and/or stainless steel chain, schedule 40 stainless steel guide rails, and stainless steel cable supports.
2. It is the intent of these specifications that the pumps, base plates, guide rails, hoisting cable and connections to the control system (including panel, starters and circuit breakers), be provided by the pump manufacturer as an integral system.
3. Pump housing shall be of heavy cast iron construction.
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Revision Date: 10/04/2019 4. All fasteners shall be minimum 304 or 304L stainless steel or Utility approved equal.
5. Each pump shall be capable of being hoisted vertically out of the wetwell, and returned to operation without requiring the operator to enter the wetwell.
6. No electrical splices shall be allowed inside the wetwell.
7. The impeller shall be of bronze, ductile iron, or other durable, corrosion- resistant approved material. The pump impeller shall be of semi-open non- clog design and shall have back vane(s) to prevent build up of solids behind the impeller. The impeller shall be rigidly fixed to the motor shaft with a key(s) or other approved fastener (so designed to prevent separation under rotational loading).
8. The motor shaft shall be stainless steel, supported by upper and lower bearings. The upper bearing shall be a self-lubricating ball bearing. The lower bearing shall be a sleeve bearing or double row ball bearing lubricated from an oil chamber. Shaft and bearing shall have sufficient section to withstand all rotational and axial loading to be reasonably expected under normal wastewater pumping situations.
9. The shaft shall be sealed from the volute with an oil-lubricated mechanical seal system. The oil chamber shall be equipped with a seal sensor system to detect any leakage around the seal system. Mechanical seal shall be tungsten carbide type, double mechanical seal. One replacement seal for each pump shall be furnished to the utility.
10. The motor chamber shall be suitably sealed from the other chambers of the pump and from the exterior to be entirely suitable for submerged operation. The motor chamber may either be of oil-filled or air-filled design.
11. Pumps shall be Xylem, Pentair or Utility approved equal.
C. Motors
1. Pump motors shall be of the sealed submersible type meeting UL Class I, Group D, Division I - Explosion proof requirements. The maximum rpm of the motor shall be as noted on the drawings or shall be approved by the Utility. Motors shall meet NEMA thermal rating MGI - 12.42. All leads are to be epoxy sealed.
2. Motors used on variable frequency drives (VFDs) shall be rated for inverter duty applications and shall be specifically approved by the Utility.
3. Moisture sensing probes and thermal protectors shall be furnished.
4. Motor frame and end shield shall be corrosion resistant cast iron.
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Revision Date: 10/04/2019 5. Insulation shall be compatible Class B rated system with Class F material rated for continuous duty in 40-degree C liquids.
6. Motor shaft shall be type 416 stainless steel.
7. All hardware shall be stainless steel.
8. Submersible pump motors shall be furnished by the pump manufacturer.
9. Motors shall not be overloaded at any point within the operating range.
10. Motors shall be furnished with a minimum of 40-feet of submersible, waterproof, and multi-conductor power and control cable. If required cables shall terminate in a NEMA 4X stainless steel (or fiberglass if allowed by the Utility) junction box at the top of the wetwell which shall be connected to the control panel by RGS conduit. Cable size shall be sufficient to meet motor requirements.
11. The external pumping chamber seals and connections shall be sealed tightly together utilizing “O” rings or resilient gasket material. The power cable connection shall provide for a positive clamping action to seal the electrical connection and relieve strain on the cable strands.
2.3 PUMP CONTROLS
A. The pump manufacturer shall provide the pump control panel and accessory equipment. The contractor shall install the controls as shown on the drawings and manufacturer’s instructions. The control system shall include all motor starters, alternators, relays, level control switches, control panel, circuit breakers, alarm apparatus, and internal wiring.
B. Level control shall primarily be controlled by mercury displacement float switches or mechanical float switches as noted on the drawings. Submersible pressure transducers for level control may be required by the Utility for some lift stations, and will be designated on the drawings if required by the Utility.
1. Mercury Displacement Float Level Control
a. Float switches shall be of the mercury tube type, encapsulated in polyurethane or vinyl floats. The units shall be waterproof, shock proof, explosion proof and equipped with sufficient submersible cable to extend to the control panel from the wet well without splicing, or to the junction box provided adjacent to the wetwell. Any required weights shall be provided by manufacturer.
b. Switches shall be suspended in the wetwell on a suitable stainless steel rack or rail. Floats shall be installed so as not to interfere with the operation or maintenance of the pumps.
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Revision Date: 10/04/2019 2. Mechanical Float Switches
a. Float switches shall be polypropylene construction with polyurethane foam core. The units shall be waterproof, shock proof, explosion proof and equipped with sufficient submersible cable to extend to the control panel from the wet well without splicing, or to the junction box provided adjacent to the wetwell. Any required weights shall be provided by manufacturer.
b. Floats shall be capable of being wired as either normally open or normally closed switch based on project requirements.
c. Switches shall have an electrical rating of 10 amp 120 VAC.
d. Switches shall be suspended in the wetwell on a suitable stainless steel rack or rail. Floats shall be installed so as not to interfere with the operation or maintenance of the pumps.
3. Submersible Pressure Transducer (if required)
a. A submersible level transducer shall be the primary mechanism for pump control and shall be provided to sense the liquid level of the wet well as shown on the plan drawings. The pressure transducer shall be installed per manufacturer’s written recommendations and instructions.
b. The manufacturer’s cable shall be ordered long enough to reach the control panel. This cable shall not be spliced.
c. The pressure transducer shall be non-freezing, operable up to 180º F.
d. The transducer housing shall be fabricated of PVC with a 2.5-inch diameter Teflon diaphragm. Silicone oil shall be used as a hydraulic fill.
e. The sensor shall be mounted using its signal cable and have a ¾- inch NPT pipe threading for pipe mounting.
f. The internal air pressure of the sensor shall be relieved to atmospheric pressure through a sealed breather system.
g. Pressure transducer shall be installed so as not to interfere with the operation or maintenance of the pumps.
h. Pressure transducer shall be anchored with minimum 10-pound mushroom type vinyl coated anchor with 316 stainless steel chain or Utility approved alternate anchoring method. Pressure transducer cable shall be anchored to stainless steel chain with plastic zip ties at 6-inch maximum intervals. Stainless steel chain
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Revision Date: 10/04/2019 shall be hung from stainless steel float bracket or other Utility approved alternate stainless steel bracket.
4. Junction Box
a. A Junction box shall be provided adjacent to the wetwell to provide for splicing float switch cables and/or pump power cables at the wetwell, to facilitate easier disconnect and removal of floats and/or pumps.
b. The junction box enclosure shall be NEMA 4X stainless steel and shall be suitable for post mounting.
C. Control Sequence
1. On rising liquid level in the wetwell, a switch shall start the lead pump. As the liquid level continues to rise, the second switch shall start the lag pump.
2. The pump(s) shall continue to operate until the liquid level recedes to the level of the third switch that shall stop the pumps.
3. The fourth switch shall energize the alarm circuit, should the liquid level rise above the lag pump start level.
4. The pumps shall automatically alternate between the “lead” and “lag” positions by means of an electric alternator in the panel.
5. The pump and control equipment shall be provided with electrical contacts, an alarm light and alarm horn which shall be mounted on the exterior of the station.
6. The alarm equipment shall be interlocked with wetwell controls to be actuated upon high wet well levels or loss of power. The alarm circuits shall be 120 VAC circuitry. A silencer button shall be mounted to the exterior of control cabinet or panel for silencing the audible alarm.
D. Control Panel
1. Control panel for the pump station shall be shipped to the site, completely prewired, pre-assembled and ready for service.
2. The control panel shall be NEMA 4X stainless steel unless otherwise specifically approved by the Utility with hinged door and lockable handle. Panel shall have a back mounting panel and a front inside hinged panel to make the control panel “dead-front” when outside door is open.
3. The control panel shall have an aluminum rain hood sized to shelter all panels including ATS, telemetry, control panel, etc., and shall be mounted on a concrete pad with a minimum thickness as shown on drawings.
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Revision Date: 10/04/2019 4. For pump stations with 75 horsepower pumps or above, a prefabricated, air conditioned, walk-in enclosure shall be provided unless otherwise specifically approved by the Utility. The enclosure shall be approved by the Utility prior to installation.
5. Electrical service to the pump station shall be provided by local Electric Provider or Base Privatized Electrical provider.
6. The control panel shall contain the following accessories housed in the enclosure:
a. A switch for each pump labeled “Hand/Off/Auto.”
b. If a VFD is furnished for pump speed control, a speed indicator and speed adjusting potentiometer for each pump shall be provided.
c. High water alarm relay wired to alarm circuit.
d. Motor moisture and thermal sensing relays wired to alarm circuit for each pump.
e. Multi-colored (or equivalent markings) circuitry to facilitate trouble shooting.
f. Elapsed time meter to indicate running time for each pump.
g. All necessary internal wiring relays, etc., to provide operation as previously described.
h. Phase monitoring capability that shall override and stop the normal operation of the pumps.
i. Pilot Lights shall be full voltage PTT N4 oil-tight with a chrome base and Push-To-Test. The following lights shall be provided:
1) Pump 1 Over temp 2) Pump 2 Over temp 3) Pump 1 Seal Failure 4) Pump 2 Seal Failure 5) Pump 1 Run 6) Pump 2 Run 7) Pump 1 Off 8) Pump 2 Off 9) High Level 10) Phase Failure 11) Power Failure
j. 120 VAC weatherproof red strobe and horn with the silencer button shall be mounted on the control cabinet or panel for the alarm
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Revision Date: 10/04/2019 conditions. The alarm lights and horns shall be provided loose for external mounting.
k. A voltage free dry contact as a composite for all alarm conditions and a voltage free dry contact for each alarm status shall be provided as follows:
1) Pump 1 Run 2) Pump 2 Run 3) Pump 1 Off 4) Pump 2 Off 5) High Level 6) Phase Failure 7) Pump 1 Seal Failure 8) Pump 2 Seal Failure
l. Branch circuit breakers as required.
m. Circuit breaker for duplex, single-phase (120 VAC) receptacle, 20 Amp optional, 1 pole.
n. Circuit breaker for each pump motor labeled “Pump 1” and “Pump 2.”
o. Circuit breaker for control circuit, 20 Amp, 1 pole.
p. Automatic electric alternator.
q. Time delay for the lag level circuit to delay restarting of the pumps after a power failure.
r. 240/480 VAC relay to enable only one pump to run on emergency power.
s. All necessary internal relays etc. to provide intrinsically safe operation as previously described.
t. A remote terminal unit (RTU).
u. An interconnect for all alarm functions in the pump control panel plus a “transferred” alarm from the automatic transfer switch shall be provided in a separate panel.
v. Contacts and wiring as required for a remote on/off control for each pump to override and stop the operation of each pump.
w. Magnetic starter for each motor with under voltage release and quick-trip ambient-compensated overload protection for each leg. Starting shall be “across the line” except where motor horsepower
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Revision Date: 10/04/2019 is greater than 25 HP, in which case, reduced voltage soft starters shall be required.
x. 120 VAC, 20-amp auxiliary duplex weatherproof GFI power receptacle mounted on the bottom or lower side on the enclosure.
y. Manual Transfer Switches (MTS)
1) If there is no permanent back-up generator at the site, then main power disconnect (manual transfer switch) shall be provided between main power and pump station for “On,” “Off,” and “Emergency.”
2) MTS shall be used for transferring load between standby power receptacle and utility.
3) MTS shall be 3-pole, double throw with center “Off” position and shall isolate the load between the utility and portable generator sources.
4) MTS shall have a solid (non-switched) isolated neutral bus.
5) Switches shall be heavy duty, rated and shall include suitable lugs for termination of conductors indicated on the drawings.
6) Enclosure shall be NEMA 4X stainless steel and shall be suitable for post mounting.
z. Standby Power Receptacles
1) One standby power receptacle shall be provided and installed by the Contractor adjacent to the MTS enclosure on the electrical riser.
2) The receptacle shall be suitable for outdoor use and shall be heavy duty, circuit-breaking type.
3) The receptacle shall be mounted in a NEMA 4X stainless steel enclosure.
4) Receptacle shall be provided with suitable backbox, mounting hardware, and threaded cap.
5) Receptacle shall have reverse contacts, ratings, and UL listing to match the plug on the Utility’s generator.
6) The Contractor shall coordinate with Utility before purchasing receptacle.
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Revision Date: 10/04/2019 7) If shown on the electrical panel drawings, an anti- condensation heater shall be supplied inside of the enclosure. The heater shall be located in a manner that it shall not cause damage to other components or the panel wiring. The heater shall be sized to minimize the effects of humidity and condensation. The heater shall include a thermostat for temperature control.
E. Safety Disconnect Switch
1. A safety disconnect switch shall be provided between the Electric Utility Power feed and the Pump Control Panel.
2. The safety disconnect switch enclosure shall be NEMA 4X stainless steel and shall be suitable for post mounting.
3. The safety disconnect switch shall be mounted on the electrical riser adjacent to the Pump Control Panel, and shall be labeled with weatherproof plate as “SAFETY POWER DISCONNECT” with minimum 1-inch letters.
F. Telemetry
1. Contractor shall furnish through a Control System Integrator. The Control System Integrator shall provide a working wireless telemetry system to remotely monitor and control the pump station from the Utility’s existing SCADA system to include but not be limited to such items as antenna, yagi antenna mounting, antenna cable, radio, SCADA HMI programming, RTU, RTU/PLC programming, circuit breakers, TVSS, PLC, relays, battery backup, etc. The Contractor is responsible for coordination of SCADA programming and start-up.
2. SCADA system shall meet the requirements of “ASUS SCADA General Standards” included with the Project Specifications. Preferred equipment and equipment manufacturers are listed in the “ASUS SCADA General Standards”. Any deviations from the “ASUS SCADA General Standards” shall be specifically approved by the Utility.
2.4 WETWELL AND APPURTENANCES
A. Pump station wetwell shall be precast concrete with monolithic base or fiberglass as detailed on the drawings. Minimum dimensions shall be as indicated on the drawings.
1. Precast Concrete Wetwell
a. The precast wetwell shall meet ASTM C913 and ASTM C478 specifications.
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Revision Date: 10/04/2019 b. A minimum 12-inch thick foundation shall be provided for the wetwell base. Concrete shall be reinforced to withstand the internal and external loads indicated plus a 100-psf live load on the top slab.
c. Wetwell base shall be provided with additional ballast if required to prevent flotation. The combination of the concrete ballast and the loading of backfill material over the concrete base shall provide adequate ballast against buoyancy under full hydrostatic head conditions.
d. Joints shall be sealed with butyl rubber mastic (Ramneck), or “O- ring” gaskets installed in accordance with the manufacturer’s instructions. All joints shall be parged on the interior and exterior with type “C” mortar.
e. Interior of wetwell and piping inside wetwell shall be factory or “field” epoxy coated to a minimum 30 mil surface dry thickness. Epoxy sealer prime coating and finish coating shall be NSP 100 and NSP 120, respectively, Carboline or Utility approved equal. If the wetwell is factory epoxy coated, touch-up “field” coating shall be required. Color shall be white or a color approved by the Utility.
f. The wetwell shall have, mounted at 18-innch above wetwell top, a junction box (if shown on the drawings) to enable quick disconnect of power leads to pump motors or floats when pulling pumps out for maintenance.
g. A sloped invert of non-shrink grout shall be constructed at the base of the wetwell. The invert shall have sufficient slope to prevent build- up of solids in the wetwell bottom.
2. Fiberglass Reinforced Plastic (FRP) Wetwell
a. The cylinder shall be made of FRP using the filament winding process. A safety factor of 2 on the minimum ultimate tensile strength of the laminate bottom shall be used in designing the basin and cylinder wall thicknesses for the station, taking into account all normally imposed loads arising from flotation, soil pressures, normal backfill, handling loads, operating loads and static loads imposed by equipment used in hoisting the pumps in and out of the station.
b. The cylinder shall be a filament wound laminate constructed by saturating continuous strand glass roving in a controlled pattern over a corrosion resistant liner that is to be 110 mils minimum thickness. The rovings shall be applied uniformly throughout the entire length of the cylinder as required to provide adequate thickness for the mechanical loads of each application. The winding pattern shall be a combination of helical and hoop wraps and shall produce a dense laminate without non-reinforced resin pockets or
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Revision Date: 10/04/2019 air bridging between the rovings. The glass content of the structural laminate shall be 60% to 70% by weight.
c. The station bottom shall be manufactured with 30% to 50% glass content, chop spray laminate, constructed by built-up layers of chop spray and woven roving applied along with a catalyzed isophthalic resin. Each layer shall be properly wetted out and rolled out so that it is free of air voids until the required wall thickness has been obtained.
d. All inside surfaces shall be smooth and free of cracks and crazing. The inside surface shall be pigmented or gel coated to a bright near white finish. All surfaces other than those made in contact with the mold surface shall be coated with air-inhibited resin or gel coat; including any cut edges of laminate.
e. The station cylinder shall be affixed to the station bottom such that the assembled components are structurally integrated, resulting in a watertight vessel which is capable of withstanding the full hydrostatic head from the exterior of the station while the station is completely empty.
f. The station shall be provided with 1 anti-flotation flange located near the bottom of the station. This anti-flotation flange shall be an integral part of the station and shall be sufficient in design to withstand the forces acting upon the station due to the subsoil water pressure. A minimum 12-inch thick foundation shall be provided for the wetwell base, and the wetwell shall be integrally connected to the base. The combination of the flange and the loading of backfill material over the concrete base shall provide adequate ballast against buoyancy under full hydrostatic head conditions.
B. The wetwell shall be equipped with 4-inch vent pipe with insect screen. Vent pipe shall be schedule 80 PVC or schedule 10 stainless steel. There shall also be an option for a second vent to accommodate positive ventilation of the wetwell.
C. Access Hatches.
1. The wetwell shall be equipped with an aluminum access hatch as shown on the drawings that shall be of adequate dimensions to pull out pumps with no obstruction.
2. Aluminum access hatches shall be exterior sidewalk, single or double leaf type as required or shown and shall be designed to support the weight of the pump unit plus 300 psf live load.
3. Doors shall be equipped with type 304 or 316 stainless steel slam lock having a key-way protected by a threaded plug, automatic hold-open arm with release handle held open in the 90-degree position, a safety chain, and a compression spring operator.
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Revision Date: 10/04/2019 4. Cover door hinges shall be heavy-duty design and be cast Type 304 or 316 stainless steel a minimum of 1/4-inch thick with 3/8-inch diameter stainless steel hinge pins.
5. The hatch shall be equipped with an aluminum lift handle that shall be flush to the top of the diamond plate cover.
6. The access cover unit shall be equipped with a hinged safety grate to provide protection against fall-through and to control access into the confined space. Grate openings shall be sized to allow for routine maintenance inspection without having to open the safety grate. The closed safety grate shall be designed to support the weight of one pump to facilitate site pump wash-down and inspection.
7. The hatch opening shall have a 4-inch elevated toe board to prevent tools from being kicked into the wet well (per OSHA 1926.502 (j)).
8. Hatches shall be Type “J” or “JD” as manufactured by the Bilco Company, Darp Associates, Halliday, or Utility approved equal. For 6’ to 8’ diameter structures, Halliday type RIR hatches are preferred.
D. All bolts, brackets, hardware, etc. for fastening items or bolting piping located in the wetwell shall be a minimum of 304 or 304L stainless steel.
2.5 VALVE VAULT
A. Valve vault shall be precast concrete, polymer concrete or fiberglass with monolithic top and bottom as indicated on the drawings.
B. Valve vault construction and access shall meet the same requirements as the wetwell construction and access, except that the access hatch may be flush to the concrete slab, i.e. 4-inch elevated toe board is not required.
C. If a sump pump is shown on the drawings, the valve vault shall have a sump pit and a duplex receptacle installed in the vault within 6-inch of the top of the structure to provide power to the sump pump.
D. Check valve shall be of the horizontal swing type with an outside weighted swing arm.
E. A ¼-inch NPT tap for pressure gages shall be supplied on both sides of the check valve for each pump. One (1) pressure gage shall be installed on the discharge side of the check valve for each pump.
F. Plug valves shall meet the requirements of Section 33 30 00 Sanitary Sewer Piping, Structures & Appurtenances.
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Revision Date: 10/04/2019 2.6 Piping
A. Piping and fittings shall be High Density Polyethylene Pipe (HDPE) from the wetwell pumps to the valve vault. Refer to Section 33 30 00 Sanitary Sewer Piping, Structures & Appurtenances for HDPE pipe and fitting requirements.
2.7 VALVE VAULT SUMP PUMP (if shown on the drawings)
A. One (1) automatic submersible sump pump, with a rated capacity of ten (10) gpm at 10-feet TDH shall be installed in the equipment capsule sump.
B. The sump pump shall be complete with a fractional horsepower motor, oil filled and hermetically sealed, designed to operate at 1,800 rpm, on a 120 volt, single phase, AC power source and draw no more than 4.2 amps.
C. A Buna-N shaft seal shall prohibit the pumped fluid from entering the motor housing.
D. The pump body shall be constructed of aluminum and polypropylene and the motor casing shall be cast aluminum.
E. The impeller shall be of polypropylene plastic and affixed to a 316 or 316L-grade stainless steel shaft.
F. The sump pump shall be “clog-proof” energy efficient design with built in thermal protection.
G. The sump pump shall have a built-in check valve on the discharge.
H. The sump pump shall operate within an approximately 3½-inch range turning on at approximately 5-inches and off at approximately 2½-inches of depth in the sump. The sump pump shall initiate a pumping cycle before the sump is filled. The pump float shall operate by sliding up and down a fixed bar.
I. The sump pump discharge piping shall be size 1½-inch schedule 80 PVC with solvent weld connections. The discharge piping system shall be complete with a union connection located on the upper and lower halves of the discharge line.
J. A PVC ball valve shall be installed on the discharge side of the check valve to enable maintenance of check valve without draining entire sump discharge line.
K. Sump pump shall discharge into wetwell as shown in the drawings.
2.8 PUMP STATION SITE
A. The pump station access road and site access shall be minimum 12-feet wide, and shall consist of material as shown in the plan details. The access road shall have a maximum slope of 10%. A vehicular turn around shall be provided outside of the fence.
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Revision Date: 10/04/2019 B. Pump station site shall be enclosed by chain link fence as shown on the drawings if required. The dimensions of the fenced in area are shown on the drawings. Fencing shall meet the requirements of Section 32 31 13 Chain Link Fences and Gates.
C. All areas inside the site fencing shall be treated with herbicide, landscaping fabric, and stone as shown on the drawings.
D. Wetwell shall be accessible on at least one side by service truck with crane mounted on rear passenger side.
E. Positive drainage away from all structures including wetwell shall be provided.
F. Control panel shall be within sight distance of wetwell and control panel access shall be facing wetwell.
G. Electrical conduits shall be installed from the control panel for all electrical and communications lines.
H. A bypass pumping connection shall be installed per drawings if required, see plan for details.
I. A freestanding jib crane shall be installed at the site per drawings if required. The crane shall have a capacity of shown on the drawings and come with a pedestal base and be equipped with stainless steel rope or chain assemblies. The Contractor shall provide a foundation for the jib crane adequate to meet the manufacturer’s specifications.
J. Yard Hydrants
1. Yard hydrants shall be galvanized or stainless steel.
2. Yard hydrants shall be automatic draining to prevent freezing when shutoff. Drain hole shall be below the frost line. Drainage stone shall be installed at drain hole depth to facilitate draining.
3. Yard hydrants shall be 30-inches above the ground surface unless otherwise noted in the plans.
4. All working parts of the yard hydrant shall be capable of being removable through the top of the yard hydrant.
5. Yard hydrants shall have lever handles, which shall be lockable or removable for security.
6. Yard hydrants shall be ¾”, 1-inch, 1-½-inch, or 2-inch in size. See plan for size required.
7. Yard hydrants shall be manufactured by Woodford Manufacturing or Utility approved equal.
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Revision Date: 10/04/2019 SECTION 3 - EXECUTION
3.1 GENERAL
A. The contractor shall install all pumps, motors, variable speed drives, and controls specified herein in accordance with the drawings and as recommended by the manufacturer.
B. Pump manufacturer shall provide pumps, motors, variable speed drives, controls and all other necessary items to make a complete installation. The contractor shall take possession of all pumps and equipment when delivered.
C. The Contractor shall provide labor, testing water and shall assist the Utility in performing field testing to check operating conditions of all pumps. The testing procedures shall be performed by the Contractor.
D. A representative of Utility shall inspect the subgrade before the setting of the wetwell.
3.1 INSTALLATION
A. Excavation, trenching, and backfilling shall conform to Section 31 20 00 Excavation, Trenching and Backfilling.
B. The Contractor shall install sewage pumping station components where indicated, according to specific equipment and piping arrangement indicated.
C. The Contractor shall grout under and around wetwell, and shall ensure that there are no voids between foundation slab and under slab of pumping station.
D. The Contractor shall fill voids between wetwell sidewalls, sleeves, and piping and shall make a watertight seal with grout.
E. Sanitary sewer piping installation requirements shall conform to Section 33 30 00 Sanitary Sewer Piping, Structures & Appurtenances. Drawings indicate the general arrangement of piping.
F. The Contractor shall connect wiring according to manufacturer’s written recommendation and instructions.
G. The Contractor shall install identifying labels permanently attached to equipment.
H. The Contractor shall install operating instruction signs permanently attached to equipment or on pumping station wall near equipment.
I. The Contractor shall prepare and paint ferrous piping in wet wells, structural-steel supports, and anchor devices with coal-tar epoxy-polyamide paint according to SSPC-Paint 16.
J. The Contractor shall paint field-welded areas to match factory coating.
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Revision Date: 10/04/2019 3.2 FIELD QUALITY CONTROL
A. The Contractor shall perform tests and inspections and prepare test reports.
B. The Contractor shall engage a factory-authorized service representative to inspect components, assemblies, and equipment installations, including connections, and to assist in testing.
C. Tests and Inspections:
1. After installing sewage pumping stations and after electrical circuitry has been energized, the Contractor shall test the pumping station operation for compliance with requirements. All water required for pump tests shall be furnished by the Contractor.
2. Leak Test: After installation, the Contractor shall charge systems and test for leaks. The Contractor shall repair leaks and retest until no leaks exist.
3. Operational Test: After electrical circuitry has been energized, the Contractor shall start the units to confirm proper motor rotation and unit operation.
4. The Contractor shall test and adjust controls and safeties. The Contractor shall replace any damaged and malfunctioning controls and equipment.
D. The Contractor shall remove and replace components that do not pass tests and inspections and retest as specified above.
3.3 STARTUP SERVICE
A. The Contractor shall engage a factory-authorized service representative to perform startup service.
B. The manufacturer’s field engineer or representative shall inspect and check the installation after erection and prior to start-up and shall certify that the completed installation is ready for start-up.
C. The manufacturer’s field engineer or representative shall adjust pumps, accessories, control settings, and safety and alarm devices.
D. The manufacturer’s field representative shall check the proper rotation, operating speed, and starting and running electrical characteristics of the operational pumping equipment and certify that they are correct.
E. The manufacturer’s representative shall also perform a drawdown test to check the pumping characteristics of the system to confirm the pump will pump the required flowrate.
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Revision Date: 10/04/2019 F. The field manufacturer’s representative shall also be available to Utility’s operating staff in addressing operational and trouble-shooting concerns of the Utility staff.
3.2 PAINTING AND TOUCH-UP
A. All metal components with the exception of the stainless steel guide rails shall be painted in accordance with Utility requirements.
B. After all equipment and appurtenances have been installed, the Contractor shall touch-up any abrasions, scratches, or patches in the surface protection of any furnished item of work. Any mud, grease, or other extraneous material shall be removed from the completed work using suitable solvents or detergent solutions.
C. Galvanized conduit pipe threads shall be touched-up.
D. The wetwell interior and piping shall be touched-up with epoxy sealer prime coating and finish coating as noted in the Wetwell specification section above.
3.3 REPAIRS TO WETWELL
A. All openings made in the wetwell for anchorages, conduit runs, pipe runs, etc., shall be sealed using a cement grout. The grout shall be neatly applied to the vacancy and shall be troweled in, and excess grout shall be immediately removed from the wetwell. Grout shall be high strength, non-shrink grout. All grouted areas shall be sealed with epoxy sealer prime coating and finish coating as noted in the Wetwell specification section above.
3.4 INSPECTION AND ACCEPTANCE
A. All work shall be subject to inspection and approval by Utility prior to final acceptance.
B. Final acceptance of the pipe shall be contingent upon all pressure and leakage tests yielding satisfactory results, submittal of accurate as-built drawings, and the Utility’s review of the results of testing.
C. Final acceptance of the project shall not be made until the Contractor has completed the total project, restoration, startup, and cleanup have been performed to the satisfaction of the Utility and all closeout documents including O&M Manuals have been submitted and approved by the Utility. Restoration and cleanup includes the acceptance and release of the NPDES Permit by State Agency responsible for NPDES permits, and release of the project by Base DPW or other agency with jurisdiction over the Base Utility Privatization Contract with the Utility if required.
END OF SECTION 33 32 17
American States Utility Services 33 32 17 - 20 Submersible Utility Wastewater Pumping Station
Revision Date: 10/04/2019