6.20.480 Lift station | Silver Lake Water and Sewer District Code

6.20.480 Lift station.

(1) General. The sewage lift station shall be Smith and Loveless, custom series buried, dry-well type or wet-well mounted as approved by the district. Construction shall be in compliance with OSHA, UL, ASTM, NEC, WAC, and other applicable codes and regulations. The station shall be designed, constructed and anchored to comply with current IBC standards.

The lift station shall have, as a minimum, two sewage pumps. The pumps shall have sufficient capacity and capability to efficiently handle the peak design flow with one pump and to ensure a minimum velocity of three feet per second in the force main. Design calculations and pump curves indicating the same shall be provided with the submittal information.

The rotor (motor) assembly shall be dynamically balanced. Add the impeller to the rotor assembly and dynamically rebalance the assembly, all to NEMA specifications for the operating RPM condition and submit documentation to the district. Pump and motor assembly shall meet the vibration tolerances established by the Hydraulic Institute, and shall be certified by the factory prior to shipment. Field vibration testing will be conducted to confirm conformance with vibration standards after installation. Failure to meet vibration standards in the field can be cause for station rejection.

The sewage lift station supplier shall check the station during installation to determine if the installation is correct. Written confirmation of each visit and recommendations shall be provided to the district.

The sewage lift station supplier shall provide a minimum of four hours of training for district personnel at the station site during startup.

The sewage lift station supplier shall provide four complete copies of maintenance and operation material to the district.

(2) Custom Series Buried Station (Wet Well/Dry Well). The station shall be a Smith and Loveless Custom Series station complying with the latest edition of Smith and Loveless standard specifications and with the district standards.

The station shall be a minimum of eight feet in diameter and the pump motor assembly and piping shall be district standard dark green in color.

The above-ground entrance hatch shall be 44 inches minimum inside diameter with a steel cover, lockable to district standards. In all areas, lighting and ventilation shall be provided to meet the requirements for a confined space entry.

The station shall be provided with a minimum of four magnesium anodes. The test box for cathodic protection shall be mounted on the electrical rack. See Detail V-LS3.

Each motor starter shall have its own independent phase loss relay wired directly to the starter’s “enable” circuit and to the RTU for alarming.

As a minimum, the station shall include the following:

(a) Vertical close-coupled, motor driven, non-clog pumps.

(b) Resilient seat gate valves.

(d) Central control panel with circuit breakers and intrinsically safe circuits.

(e) Motor starters.

(f) Shelf mounted air compressor two 9L25 bubbler system for automatic pumping level controls.

(g) Lighting.

(h) Sump pump with dedicated simplex, gray, 20A, non-GFCI receptacle in cast aluminum weatherproof box with full in-service cover.

(i) Ventilating blower.

(j) Blower timer.

(k) Dehumidifier.

(l) All internal wiring.

(m) Protection against corrosion.

(n) Station flooding alarm.

(o) Operator in trouble emergency button.

(p) Extended warranty – 24 months from startup or 30 months from time of shipment whichever is first.

(q) Document certifying the lift station is in compliance with the NEC.

(r) Convenience receptacles, white, duplex, 20A, GFCI, in cast aluminum weatherproof boxes with full in-service covers.

(s) Spare parts each pump:

(i) Replacement pump shaft seal – one for each pump.

(ii) Filter element for the seal filters – one for each pump.

(iii) Volute gaskets – two for each pump.

(t) Touch up paint kit.

(u) Ductile iron piping between wet well and station.

(v) Common reinforced concrete base slab for station and wet well.

(w) 316 stainless steel sump pump piping from the sump pump to the wet well with check valve and unions. Piping to go up dry well entry and discharge through the connection opening in the entry tube.

(x) Air bubbler line to go up dry well entry, above ground level, back down and discharge through connection openings in entry tube. Air bubbler line shall be 316 stainless steel tubing in the station and three-quarter-inch-diameter 316 stainless steel pipe from the entry tube to a wet well mounted tee with three-eighth-inch stainless steel pipe extended down from the wet well mounted tee to six inches above the inlet of the suction pipes.

(y) The wet well shall be a minimum of eight feet in diameter. The wet well shall provide for the volume of the pumps to be fully submerged.

(z) The wet well shall be of precast concrete construction with flat slab cover and four-by-six (two-door) hatch for access. The flat slab concrete cover shall be provided with a four-inch vent, which is “hooked and screened.”

(3) Wet Well Mounted Station. The station shall be Smith and Loveless wet well mounted vacuum primed station complying with the latest edition of Smith and Loveless standard specifications and with the district standards.

Each motor starter shall have its own independent phase loss relay wired directly to the starter’s “enable” circuit and to the RTU for alarming.

As a minimum, the station shall include the following:

(a) Vertical, close-coupled, motor driven, vacuum-primed, non-clog pumps.

(b) Resilient seat gate valves.

(d) Central control panel with circuit breakers and intrinsically safe circuits.

(e) Motor starters.

(f) Shelf mounted air compressor two-bubbler system automatic pump level controls. Shelf to be mounted at the same level or higher as the top of the station side wall.

(g) Heater.

(h) Ventilating blower.

(i) Priming pumps and appurtenances.

(j) All internal wiring.

(k) Discharge pipe welded to the base plate and to be flanged below.

(l) Bubbler piping above the base plate, plastic tubing, and below the base plate to be three-eighth-inch-diameter 304 stainless steel pipe extended down to six inches above the inlet of the suction pipes.

(m) Lid to be two-piece design with hydraulic hood assist.

(n) Paint station with dark green epoxy.

(o) Shelf mounted vacuum pumps located at the same level or higher as the top of the station side wall.

(p) Extended warranty – 24 months from startup or 30 months from time of shipment whichever is first.

(q) Document certifying the lift station is in compliance with the NEC.

(r) Convenience receptacles, white, duplex, 20A, GFCI, in cast aluminum weatherproof boxes with full in-service covers.

(s) Three-quarter-inch conduit connection in electric panel for connection to the telemetry sub panel.

(t) Spare parts for each pump:

(i) Replacement pump shaft seal – one for each pump.

(ii) Volute gaskets – two for each pump.

(u) Touch up paint kit.

(v) AWWA C900 PVC suction pipes.

(w) Flexible restrained coupling (Romac Adaptor RFCA) to connect station to suction pipes.

(x) The wet well shall be a minimum of eight feet in diameter.

(4) Motors. The pump and motor shafts shall be the maximum diameter available for these units.

Pump motors shall be three-phase, 60-cycle, 480-voltage inverter rated, TEFC. Motors 40 hp and larger shall be furnished with soft start or variable frequency drives (VFDs). VFDs shall comply with the latest ANSI, IEEE, and NEC codes. VFD load circuits from starter to motor shall be shielded power cables in RGS conduits. All VFDs shall be Allen Bradley.

The motors shall have 1.15 service factor and be nonoverloading for the full range of the curve unless otherwise approved by the district.

(a) General. The wet well shall be precast concrete manhole sections. Joints between precast wall sections shall be confined O-ring or as otherwise approved. The poured in place slab top shall be designed with the wet well to exceed buoyant forces and shall have a cast in place flush mount safety system sleeve per district standard detail.

The wet well shall be provided with polypropylene manhole steps as specified for manholes.

The wet well shall be checked to ensure all joints are watertight to prevent infiltration and exfiltration of the wet well.

The wet well floor, walls and underside of the top shall be coated to comply with the following:

(i) Surface Preparation. Allow a minimum of 28 days cure time for concrete. Sweep blast to provide a surface profile. Surface shall be clean, dry and free of contaminants.

(ii) Exterior Surfaces. The exterior surface of the wet well shall be coated with 30 mils minimum of coal tar epoxy.

(A) Filler and Surfacer. Tnemec Series 218 Filler and Surfacer. Applied as needed. After the application of the prime coat, the bugholes and surface voids shall be filled to ensure that the finish coat is monolithic and pinhole free.

(B) Finish. Tnemec Series 435 Perma-Glaze. Applied in two coats at 15 mils dry film thickness each. Color light gray.

Comply with all conditions of the manufacturer’s specifications for preparation and application.

(6) Controls. The control panel shall include:

(a) Main disconnect.

(b) Panel mounted running light for each pump.

(d) Panel mounted running time meter for each pump.

(e) Panel mounted Cutler Hammer HOA switches for each pump.

(f) Mounting bracket for telemetry sub panel in station (size: 13.5 inches long by 10 inches wide by six and one-half inches deep).

(g) Local/remote contact for the following alarms:

(i) Low level.

(ii) High level.

(iii) Power/phase failure (single and three-phase).

(iv) Pump failure.

(v) High water (dry well).

(vi) Pump on.

(vii) Intrusion.

(h) Panel mounted wet well gauge. Minimum two-and-one-half-inch dial and read for depth of wet well in inches (Model Marsh Bellofram No. G 22 687).

(i) Phase monitor to protect the pump motors from single-phase reversal and low voltage.

(j) Discharge check valve limit switches (each).

(k) Pump alternator, each cycle.

(l) High water float pump control.

(a) General. Codes and regulations exist at the federal, state, and local level dictating minimum acceptable requirements for electrical systems. The following standards shall be used as a basis for design and review:

(i) National Electric Code (NEC).

(ii) Occupational Safety and Health Act (OSHA).

(iii) State and local building codes.

(iv) National Electrical Safety Code (NESC).

(v) National Electrical Manufacturers Association (NEMA).

(vi) Underwriters’ Laboratory (UL).

(vii) Insulated Power Conductor Engineering Association (IPCEA).

(viii) American National Standards Institute (ANSI).

(ix) Institute of Electrical and Electronic Engineers (IEEE).

(b) Electrical Service. The local electric utility will be the primary source of electrical power. The developer shall ascertain proper coordination between the nominal secondary delivery voltage supplied by Snohomish County PUD No. 1 and the connection to the lift station equipment. The electrical service shall be 480/277V four-wire, three-phase, 60 hertz, with a solid neutral terminal at the disconnect or as may otherwise be required by Snohomish County PUD No. 1. This shall be confirmed with the Snohomish County PUD No. 1 and confirmed by the suppliers.

All installation shall be approved by Snohomish County PUD No. 1 and shall be in conformance with the NEC (current issue), UL, OSHA and county and state electrical codes.

The district shall be furnished with a certificate of final inspection by the inspecting agency.

All wire shall be stranded copper.

All conduit shall be rigid galvanized steel (RGS). All underground RGS conduits, elbows, and fittings shall be coated with 20 mils (minimum) of PVC coating or a half-lapped wrap of Scotchwrap No. 51. See Detail V-LS4.

All underground conduits shall be covered with a strip of yellow polyethylene tape placed six inches below finished grade and directly above the conduit.

All conduit shall have a minimum of two feet of cover.

Instrumentation conduits, elbows and fittings shall be RGS over their entire length.

Heating strips shall be provided for outside electrical enclosures.

A service entrance shall be provided with a pedestal on which shall be mounted, as a minimum, the following equipment:

(i) Meter and meter can (as required by the PUD).

(ii) Meter C.T.S. (as required by the PUD).

(iii) Main disconnect SUSE-rated circuit breaker in a NEMA 3R enclosure, with padlock to district standards.

(iv) Service voltage shall be 480/277 volts, three-phase, four-wire, except as required by Snohomish County PUD No. 1.

(v) Single phase services shall be 240/120 volt, three-wire. Panels shall conform with NEMA 3R.

(vi) A 120-volt duplex in NEMA 3R enclosure with padlock to district standards on the electrical rack.

(vii) Ground rod and connector wire in conduit to NEC standards.

(viii) Mount equipment per Detail V-LS3.

(ix) Provide a complete electrical plan set including the following minimum documents:

(A) Electrical plan view showing equipment and interconnecting conduits.

(B) A cable and conduit schedule.

(D) Motor starter control schematics.

(E) Panelboard schedule.

(F) Main control panel schematics.

(G) PLC I/O tables.

(H) Associated electrical details.

(x) The district shall be provided with a complete reproducible set of as-constructed plans and details showing final location of all equipment, conduit and wire.

(c) Controls. Control and instrument system plans shall thoroughly and completely depict system design. The plans, in conjunction with the specifications, shall define the type of control system, the type of components in the system, set points and the interface between the instrumentation and control system and the lift station system. To accomplish this, the control and instrument plan(s) shall include, as a minimum, the following:

(i) Control and instrumentation system legend and general notes.

(ii) Control, instrumentation and distribution diagram.

(iii) Plans showing location of all control, instrument, and distribution system equipment and components, both electrical and pneumatic.

(iv) All equipment and installation details.

The power, control and instrumentation systems shall be designed with both operational reliability and maintainability. Use standard products wherever possible.

Electrical equipment and devices shall be connected using separate power, control, and instrumentation conduits. Electrical gutters or fabricated raceways shall not be used.

All components within the lift station system, including both internally and face-mounted instruments and devices, shall be clearly identified with phenolic nameplates of black background with white letters reverse engraved from the backside (smooth front surface).

Intrinsically safe electrical circuits shall be installed in the main control panel in compliance with NEC, not in the motor starters.

All wiring between cabinet, equipment and components shall be labeled and color coded where applicable.

All pump motors shall have an independent lockable circuit breaker located within the lift station and the lift station shall have a lockable main circuit breaker located outside the lift station.

Lead and lag pump functionality shall alternate between pumps on each cycle change.

The pump controls shall be air bubbler type with two compressors alternating on timer control, and shall provide for both pumps to operate at high water conditions. The control elevations shall be indicated on the plans, i.e., on-off, first pump on, second pump on, and high water alarm. The air compressors shall not be located in electrical cabinets or enclosures.

The wet well shall be equipped with a high water redundant float to override the bubbler pump control and start the pumps and send high wet well level alarm.

A complete set of spare fuses shall be provided for all fused equipment.

(d) Telemetry. The district’s telemetry system utilizes Allen Bradley Compact Logics for SCADA functions related to the wastewater collection systems. The PLCs report to a master unit at the District Headquarters. The master unit communicates with a personal computer running inductive automation ignition software to allow supervisory control and data acquisition functions to take place.

The PLCs shall be provided in enclosures with auxiliary equipment to facilitate connection of external signals to the PLCs, and to monitor voltage, intrusion, and similar status signals. Communication with the District Headquarters shall be via ethernet IP.

For each new lift station, the developer shall provide an Allen Bradley Compact Logics PLC (with Modbus option, accumulator/pulse counter access and battery backup) along with an enclosure, power supply, relays, surge protection devices for power and ethernet connections, and other auxiliary devices as required for proper operation of the system. Typical discrete inputs for a station include:

(i) Utility power fail.

(ii) Three-phase power fail (phase reversal, phase imbalance, phase loss, undervoltage, and overvoltage).

(iii) Generator run.

(iv) Generator fail.

(v) ATS in standby.

(vi) Intrusion alarm.

(vii) Wet well high level.

(viii) Wet well low level.

(ix) Pump No. 1 run.

(x) Pump No. 2 run.

(xi) Pump No. 1 fail.

(xii) Pump No. 2 fail.

(Note: Additional pump run and fail signals are required for each pump when the station has more than two pumps.)

(xiii) Station flood (buried station).

(xiv) Ventilation fail (buried station).

(xv) Operator in trouble (buried station).

(xvi) Flow meter totalizer.

(xvii) All exterior transfer switches will be NEMA 3 enclosure with keyed switch for access to controls.

Typical discrete outputs include: start generator (with an interposing relay driven by the PLC in the telemetry subpanel).

Typical analog inputs include:

(i) Pump No. 1 amperes.

(ii) Pump No. 2 amperes.

(iii) Wet well level.

(iv) Flow rate.

Provisions shall also be made for additional I/O signals by providing terminals from each I/O point on the PLC to terminals within the telemetry panel.

The telemetry panel and all items contained therein shall be provided by Systems Interface, Inc., (425) 481-1225.

Programming of the PLC and HMI shall be performed by Infinium Engineering and Consulting, Inc., of Yakima, WA.

The developer shall also be responsible for correct set-up of the PLC with respect to the existing system configuration. This includes coordinating configuration parameters such as:

(i) PLC addressing.

(ii) Master unit configuration.

(iii) PLC configuration.

(iv) I/O point configuration (enable/disable format).

(v) Debounce time.

(vi) NO/NC inputs.

(vii) Percent change reporting.

(viii) High/low alarm limits.

(ix) Accumulator sampling rates.

(x) Momentary/latched outputs.

(xi) Signal adjustments (receive gain, transmit gain).

(xii) Rebalancing of the district’s Verizon dedicated telemetry circuit.

The developer shall coordinate with the telephone utility and the district for obtaining proper telephone service to the site. The developer shall be responsible for obtaining, installing, and starting up the PLC for the new lift station. The developer shall coordinate obtaining, installing and starting up the PLC with the district to ensure that the station is properly configured and functions correctly in conjunction with the existing system.

All major components, including relays, timers, and power supplies shall be identified using phenolic or vilam engraved labels.

A line (surge) protector unit shall be provided for the telemetry equipment. The unit shall protect the equipment from transient and electrical surges on the telephone line. Protection shall include line fuses and clamps for voltages over 25 volts, gas tubes shall be provided as an integral part of the lighting protection unit.

(a) General. Standby power generation equipment shall be provided at the lift station site, which will operate the lift station in the event of a commercial power outage.

The standby system shall be designed with capacity and rating to safely start and operate the entire connected lift station load, including all pumps and ancillary loads, unless otherwise approved by the district. All applicable codes shall be followed, including NEC and UPC.

The generator set shall be complete in every respect and shall include, but not be limited to, the following:

(i) Generator, control panel and circuit breaker.

(ii) Engine, radiator and exhaust system.

(iii) Fuel tank, diesel only. (Capacity for seven days at 25 percent load.)

(iv) Alum-Tek generator set enclosure providing noise attenuation in compliance with Chapter 173-60 WAC, and lockable to district standards.

(v) Automatic transfer switch – single electric motor style.

(vi) Block heater.

(vii) Battery and rack.

(viii) Battery charger.

(ix) Conduit, wire and piping.

The generator set and transfer switch shall be Cummins/Onan complying with the latest edition of Onan Corporation standard specifications and district standards or a district approved equal generator set and transfer switch.

The generator set shall be spark-ignited, liquid propane; 60 Hertz, 1,800 rpm, three-phase, 480/277 volt standby power or diesel if approved by the district. Diesel required for generator sets greater than 150 kW.

The generator set shall include the following:

(i) Engine. Single phase, 1,500 watt block heater (115 Vac).

(A) Mainline circuit breaker.

(B) Five-year basic power warranty.

(A) Batteries.

(B) Battery charger, two-amp, 12 VDC, 120 Vac input.

(A) Annunciator relays (12).

(B) Run relay package (three).

(D) Anti-condensation space heater, 120 Vac.

(E) Oil temperature gauge.

(F) Wattmeter.

(G) Emergency stop switch.

(v) Fuel Systems. Diesel unless approved by the district. All piping shall be black iron, except for flexible vibration isolation connections at pipe ends with shut off ball valves.

(vi) Alternator. Anti-condensation heater, 120 Vac.

(A) Run-stop-remote switch.

(B) Remote starting, 12-volt, two-wire.

(D) Field circuit breaker.

(E) DC voltmeter.

(F) Running time meter.

(G) Lamp test switch.

(H) Oil pressure gauge.

(I) Fault reset switch.

(J) Cycle cranking.

(K) Twelve-light engine monitor with individual one-half amp relay signals and a common alarm contact for each of the following conditions:

1. Run (green light).

2. Pre-warning for low oil pressure (yellow light).

3. Pre-warning for high coolant temp (yellow light).

4. Low oil pressure shutdown (red light).

5. High coolant temperature shutdown (red light).

6. Overcrank shutdown (red light).

7. Overspeed shutdown (red light).

8. Switch off (flashing red light indicates generator set not in automatic start mode).

9. Low coolant temperature (yellow light).

10. Low fuel (yellow light).

11. Two customer selected faults (red light).

(viii) AC Meter Package. Order with NFPA 110 monitor to meet code requirements:

(A) AC voltmeter (dual range).

(B) AC ammeter (dual range).

(D) Dual scale frequency meter/tachometer.

(E) AC rheostat (panel mounted) for plus five percent voltage adjust.

The transfer switch shall include the following:

(i) Sized for full station and auxiliary equipment load plus 25 percent.

(ii) Pole Configuration. Poles – Three (solid neutral).

(iii) Frequency. Sixty Hertz.

(iv) Application. Appl – Utility to genset.

(v) System Options. Three phase, three-wire or four-wire.

(vi) Enclosure. Alum-Tek or equal generator will be installed in a 12-gauge galvanized welded steel, insulated, sound attenuated, NEMA 3R weather-protective, walk-in drop over acoustical enclosure. The enclosure will meet the requirements of ASTM A-653 and the current IBC. The sound pressure level will average not more than 45 dBA at 110 feet in a free-field condition, or 53 dBA at 23 feet, or will meet more stringent sound requirements as specified by the district.

(vii) Listing. Listing – UL 1008.

(viii) Programmed Transition. Program transition, one to 60 seconds.

(ix) Applications Modules. Monitor – Phase sequence/balance.

Suitable guards shall be provided on all electrical parts to minimize the personal shock hazard.

Generator shall be broken-in sufficiently to permit application of full load immediately upon installation.

Generator supplier shall provide all tools for the generator set as recommended and required by the manufacturer.

Generator installation shall be checked by the supplier after installation to determine that the installation is correct. Written confirmation shall be provided to the district. Generator supplier shall perform a full load test for two hours after installation is complete. Provide resistive load bank for this test.

Generator supplier shall provide a minimum of four hours of training for district personnel at the station site during startup.

Generator manufacturer shall provide four copies of the maintenance and operation manual. These manuals shall be complete and shall include all information necessary to allow district personnel to maintain the generator.

Generator mounting pad shall be reinforced concrete to carry the weight of the unit and shall extend a minimum of three inches beyond generator housing. All formed edges to be one-half round or three-quarter-inch chamfer.

Diesel tanks shall be Convault AST, or approved equal, equipped with external fuel shutoff valve. [Res. 735 § 1, 2017.]