Jacksonville\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Duval County\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 904-346-1266
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\nOrange Park\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Clay County\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 904-264-6444
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\nPalm Coast\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Flagler County\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 386-439-5290
\nDaytona\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Volusia County\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 386-253-4911
\nServing all of Florida \u00a0and Georgia\u00a0\u00a0\u00a0 at \u00a0\u00a0\u00a0\u00a0904-346-1266<\/p>\n
EMAIL <\/strong>LARRY@1STPROP.COM<\/a> (feel free to email your bidding packages here)<\/p>\n MONTHLY SERVICE AVAILABLE<\/p>\n MONTHLY SERVICE CONTRACTS<\/p>\n LIFT STATION INSPECTIONS<\/p>\n LICENSED LIFT STATION COMPANY<\/p>\n INSURED<\/p>\n FREE ESTIMATES<\/p>\n STATE OF FLORIDA CERTIFIED PLUMBING CONTRACTOR<\/p>\n CFCO56659<\/p>\n LIFT STATION PUMPS<\/p>\n LIFT STATION CRANE<\/p>\n CONTROL PANELS<\/p>\n RAILS<\/p>\n we have a team of \t\texperienced individuals who come into your plant OR BUSINESS\u00a0 with a fresh pair of \t\teyes.\u00a0 The system is checked from influent to effluent.\u00a0 System \t\toptimization, equipment efficiency and operational excellence are key \t\tcomponents explored. Key Benefits Equipment efficiency Total Cost of \t\tOperation reductions Reliability and safety<\/p>\n An onsite audit is conducted to examine system parameters, process controls, and current monitor and control procedures. A physical walk-through is conducted, process flow diagrams are examined, previous design criteria are examined and current standard operating procedures are evaluated along with data logs.<\/p>\n NOW HIRING<\/strong><\/p>\n apply for a job online at www.asapapply.com<\/a><\/strong><\/p>\n <\/strong><\/p>\n \n CLICK BELOW AND PLACE A WORK ORDER<\/span><\/span><\/p>\n IN OUR AUTOMATED WORK ORDER SYSTEM<\/span><\/span><\/p>\n http:\/\/www.asap-plumbing.com\/Submit_a_New_Work_Order\/submit_a_new_work_order.php<\/a><\/span><\/span><\/p>\n <\/span><\/span> <\/strong><\/p>\n Wastewater \tlift stations are used to help transport liquid wastewater from homes and \tbusinesses across the City to the treatment plant for processing and \tcleaning.<\/p>\n Lift Stations <\/strong><\/p>\n Sewage lift stations are by definition installed in a difficult operating \tenvironment. The commonly used prefabricated steel “can” stations are \tconstantly subjected to a corrosive environment on both the interior and \texterior of the station. Because these structures are out of sight they \toften do not receive the type of care and maintenance needed to protect \tsteel surfaces.<\/p>\n ignificant problem many times with lift stations is odor generation. In \taddition to concerns for sewer personnel exposed to accumulated gases, sewer \tgases left to accumulate in air-tight environments can create additional \ttoxic gases and underground potential for explosion, stagnation, and dead \tspace in lines. Aeration is an option to reduce odor. Many ODORS accumulate because of oxygen-deficient \tenvironments. The cost to retrofit old sewer systems (lines, stations, can \tbe astronomical for a municipality.\u00a0\u00a0 Sometimes chemicals such as \tsodium nitrate are added to increase oxygen content in the water and provide \tthe bacteria\u00a0 an alternate oxygen source when free oxygen from \tmechanical sources is not available. This prevents H2S formation from \tfacultative or anaerobic bacteria. Pine Scented blocks also have been added \tto neutralize odors so that neighbors are not complaining.<\/p>\n Grease<\/span><\/p>\n <\/strong>Fats, oil and grease – – also called FOG in the wastewater business – – \tcan have negative impacts on wastewater collection and treatment systems. \tMost wastewater collection system blockages can be traced to FOG. Blockages \tin the wastewater collection system are serious, causing sewage spills, \tmanhole overflows, or sewage backups in homes and businesses. With the \tincrease in fast food restaurants, many municipalities are having problems \twith an increase in grease build-up in their lift stations.<\/p>\n <\/span><\/p>\n Why \tis grease a problem?<\/strong><\/p>\n In the sewage collection and treatment business Grease is singled out for \tspecial attention because of its poor solubility in water and its tendency \tto separate from the liquid solution.<\/p>\n Large amounts of oil and grease in the wastewater cause trouble in the \tcollection system pipes. It decreases pipe capacity and, therefore, requires \tthat piping systems be cleaned more often and\/or some piping to be replaced \tsooner than otherwise expected. Oil and grease also hamper effective \ttreatment at the wastewater treatment plant. Grease is the number one cause \tof foaming and bulking, especially Nocardia and M. parvicella.<\/p>\n Grease in a warm liquid may not appear harmful. But, as the liquid cools, \tthe grease or fat congeals and causes nauseous mats on the surface of \tsettling tanks, digesters, and the interior of pipes and other surfaces \twhich may cause a shutdown of wastewater treatment units.<\/span><\/span><\/p>\n Bioaugmentation Solutions for Lift stations, \tWet Wells and Collection Systems<\/p>\n <\/span><\/a>Solid block biological products \tthat are specifically formulated and packaged for use in lift stations and \tlarge restaurant grease traps to remove grease build-up and help increase \tdegradation capabilities.<\/p>\n This biological product is a high strength \tformulation developed to degrade fats oils and grease quickly. It can be \tused in restaurants, grease traps and drain fields where food based grease \tis a problem.<\/p>\n This product is an improved biological product, \tspecifically formulated and packaged for use in sewers to help degrade \tgrease build-up and stop blockage.<\/p>\n we have a team of \t\texperienced individuals who come into your plant with a fresh pair of \t\teyes.\u00a0 The system is checked from influent to effluent.\u00a0 System \t\toptimization, equipment efficiency and operational excellence are key \t\tcomponents explored. Key Benefits Equipment efficiency Total Cost of \t\tOperation reductions Reliability and safety<\/p>\n An onsite audit is conducted to examine system parameters, process controls, and current monitor and control procedures. A physical walk-through is conducted, process flow diagrams are examined, previous design criteria are examined and current standard operating procedures are evaluated along with data logs.<\/p>\n United States Operation and Maintenance Costs other websites we recommend you look at:<\/strong><\/p>\n
\n<\/span><\/span><\/p>\nServing the entire Jacksonville area including the following communities:<\/h4>\n
\n
\nEnvironmental Protection
\nAgency
\nOffice of Water
\nWashington, D.C.
\nEPA 832-F-00-073
\nSeptember 2000
\nCollection Systems
\nTechnology Fact Sheet
\nSewers, Lift Station
\nDESCRIPTION
\nWastewater lift stations are facilities designed to
\nmove wastewater from lower to higher elevation
\nthrough pipes. Key elements of lift stations include
\na wastewater receiving well (wet-well), often
\nequipped with a screen or grinding to remove
\ncoarse materials; pumps and piping with associated
\nvalves; motors; a power supply system; an
\nequipment control and alarm system; and an odor
\ncontrol system and ventilation system.
\nLift station equipment and systems are often
\ninstalled in an enclosed structure. They can be
\nconstructed on-site (custom-designed) or prefabricated.
\nLift station capacities range from
\n76 liters per minute (20 gallons per minute) to more
\nthan 378,500 liters per minute (100,000 gallons per
\nminute). Pre-fabricated lift stations generally have
\ncapacities of up to 38,000 liters per minute (10,000
\ngallons per minute). Centrifugal pumps are
\ncommonly used in lift stations. A trapped air
\ncolumn, or bubbler system, that senses pressure and
\nlevel is commonly used for pump station control.
\nOther control alternatives include electrodes placed
\nat cut-off levels, floats, mechanical clutches, and
\nfloating mercury switches. A more sophisticated
\ncontrol operation involves the use of variable speed
\ndrives.
\nLift stations are typically provided with equipment
\nfor easy pump removal. Floor access hatches or
\nopenings above the pump room and an overhead
\nmonorail beam, bridge crane, or portable hoist are
\ncommonly used.
\nThe two most common types of lift stations are the
\ndry-pit or dry-well and submersible lift stations. In
\ndry-well lift stations, pumps and valves are housed
\nin a pump room (dry pit or dry-well), that is easily
\naccessible. The wet-well is a separate chamber
\nattached or located adjacent to the dry-well (pump
\nroom) structure. Figures 1 and 2 illustrate the two
\ntypes of pumps.
\nSubmersible lift stations do not have a separate
\npump room; the lift station header piping,
\nassociated valves, and flow meters are located in a
\nseparate dry vault at grade for easy access.
\nSubmersible lift stations include sealed pumps that
\noperate submerged in the wet-well. These are
\nremoved to the surface periodically and reinstalled
\nusing guide rails and a hoist. A key advantage of
\ndry-well lift stations is that they allow easy access
\nfor routine visual inspection and maintenance. In
\ngeneral, they are easier to repair than submersible
\npumps. An advantage of submersible lift stations is
\nthat they typically cost less than dry-well stations
\nand operate without frequent pump maintenance.
\nSubmersible lift stations do not usually include
\nDry Well
\nWet Well
\nInlet
\nHoist
\nDischarge
\nSource: Qasim, 1994.
\nFIGURE 1 DRY-WELL PUMP
\nlarge aboveground structures and tend to blend in
\nwith their surrounding environment in residential
\nareas. They require less space and are easier and
\nless expensive to construct for wastewater flow
\ncapacities of 38,000 liters per minute (10,000
\ngallons per minute) or less.
\nAPPLICABILITY
\nLift stations are used to move wastewater from
\nlower to higher elevation, particularly where the
\nelevation of the source is not sufficient for gravity
\nflow and\/or when the use of gravity conveyance
\nwill result in excessive excavation depths and high
\nsewer construction costs.
\nCurrent Status
\nLift stations are widely used in wastewater
\nconveyance systems. Dry-well lift stations have
\nbeen used in the industry for many years. However,
\nthe current industry-wide trend is to replace drywell
\nlift stations of small and medium size
\n(typically less than 24,000 liters per minute or 6,350
\ngallons per minute) with submersible lift stations
\nmainly because of lower costs, a smaller footprint,
\nand simplified operation and maintenance.
\nVariable speed pumping is often used to optimize
\npump performance and minimize power use.
\nSeveral types of variable-speed pumping equipment
\nare available, including variable voltage and
\nfrequency drives, eddy current couplings, and
\nmechanical variable-speed drives. Variable-speed
\npumping can reduce the size and cost of the wetwell
\nand allows the pumps to operate at maximum
\nefficiency under a variety of flow conditions.
\nBecause variable-speed pumping allows lift station
\ndischarge to match inflow, only nominal wet-well
\nstorage volume is required and the well water level
\nis maintained at a near constant elevation.
\nVariable-speed pumping may allow a given flow
\nrange to be achieved with fewer pumps than a
\nconstant-speed alternative. Variable-speed stations
\nalso minimize the number of pump starts and stops,
\nreducing mechanical wear. Although there is
\nsignificant energy saving potential for stations with
\nlarge friction losses, it may not justify the additional
\ncapital costs unless the cost of power is relatively
\nhigh. Variable speed equipment also requires more
\nroom within the lift station and may produce more
\nnoise and heat than constant speed pumps.
\nLift stations are complex facilities with many
\nauxiliary systems. Therefore, they are less reliable
\nthan gravity wastewater conveyance. However, lift
\nstation reliability can be significantly improved by
\nproviding stand-by equipment (pumps and controls)
\nand emergency power supply systems. In addition,
\nlift station reliability is improved by using non-clog
\npumps suitable for the particular wastewater quality
\nand by applying emergency alarm and automatic
\ncontrol systems.
\nADVANTAGES AND DISADVANTAGES
\nAdvantages
\nLift stations are used to reduce the capital cost of
\nsewer system construction. When gravity sewers
\nare installed in trenches deeper than three meters
\n(10 feet), the cost of sewer line installation
\nincreases significantly because of the more complex
\nand costly excavation equipment and trench shoring
\ntechniques required. The size of the gravity sewer
\nlines is dependent on the minimum pipe slope and
\nflow. Pumping wastewater can convey the same
\nflow using smaller pipeline size at shallower depth,
\nand thereby, reducing pipeline costs.
\nHoist
\nDischarge
\nSource: Qasim, 1994.
\nFIGURE 2 WET-WELL SUBMERSIBLE
\nDisadvantages
\nCompared to sewer lines where gravity drives
\nwastewater flow, lift stations require a source of
\nelectric power. If the power supply is interrupted,
\nflow conveyance is discontinued and can result in
\nflooding upstream of the lift station, It can also
\ninterrupt the normal operation of the downstream
\nwastewater conveyance and treatment facilities.
\nThis limitation is typically addressed by providing
\nan emergency power supply.
\nKey disadvantages of lift stations include the high
\ncost to construct and maintain and the potential for
\nodors and noise. Lift stations also require a
\nsignificant amount of power, are sometimes
\nexpensive to upgrade, and may create public
\nconcerns and negative public reaction.
\nThe low cost of gravity wastewater conveyance and
\nthe higher costs of building, operating, and
\nmaintaining lift stations means that wastewater
\npumping should be avoided, if possible and
\ntechnically feasible. Wastewater pumping can be
\neliminated or reduced by selecting alternative sewer
\nroutes or extending a gravity sewer using direction
\ndrilling or other state-of-the-art deep excavation
\nmethods. If such alternatives are viable, a costbenefit
\nanalysis can determine if a lift station is the
\nmost viable choice.
\nDESIGN CRITERIA
\nCost effective lift stations are designed to: (1)
\nmatch pump capacity, type, and configuration with
\nwastewater quantity and quality; (2) provide
\nreliable and uninterruptible operation; (3) allow for
\neasy operation and maintenance of the installed
\nequipment; (4) accommodate future capacity
\nexpansion; (5) avoid septic conditions and
\nexcessive release of odors in the collection system
\nand at the lift station; (6) minimize environmental
\nand landscape impacts on the surrounding
\nresidential and commercial developments; and (7)
\navoid flooding of the lift station and the
\nsurrounding areas.
\nWet-well
\nWet-well design depends on the type of lift station
\nconfiguration (submersible or dry-well) and the
\ntype of pump controls (constant or variable speed).
\nWet-wells are typically designed large enough to
\nprevent rapid pump cycling but small enough to
\nprevent a long detention time and associated odor
\nrelease.
\nWet-well maximum detention time in constant
\nspeed pumps is typically 20 to 30 minutes. Use of
\nvariable frequency drives for pump speed control
\nallows wet-well detention time reduction to 5 to 15
\nminutes. The minimum recommended wet-well
\nbottom slope is to 2:1 to allow self-cleaning and
\nminimum deposit of debris. Effective volume of
\nthe wet-well may include sewer pipelines,
\nespecially when variable speed drives are used.
\nWet-wells should always hold some level of sewage
\nto minimize odor release. Bar screens or grinders
\nare often installed in or upstream of the wet-well to
\nminimize pump clogging problems.
\nWastewater Pumps
\nThe number of wastewater pumps and associated
\ncapacity should be selected to provide headcapacity
\ncharacteristics that correspond as nearly as
\npossible to wastewater quantity fluctuations. This
\ncan be accomplished by preparing pump\/pipeline
\nsystem head-capacity curves showing all conditions
\nof head (elevation of a free surface of water) and
\ncapacity under which the pumps will be required to
\noperate.
\nThe number of pumps to be installed in a lift station
\ndepends on the station capacity, the range of flow
\nand the regulations. In small stations, with
\nmaximum inflows of less than 2,640 liters per
\nminute (700 gallons per minute), two pumps are
\ncustomarily installed, with each unit able to meet
\nthe maximum influent rate. For larger lift stations,
\nthe size and number of pumps should be selected so
\nthat the range of influent flow rates can be met
\nwithout starting and stopping pumps too frequently
\nand without excessive wet-well storage.
\nDepending on the system, the pumps are designed
\nto run at a reduced rate. The pumps may also
\nalternate to equalize wear and tear. Additional
\npumps may provide intermediate capacities better
\nmatched to typical daily flows. An alternative
\noption is to provide flow flexibility with variablespeed
\npumps.
\nFor pump stations with high head-losses, the singlepump
\nflow approach is usually the most suitable.
\nParallel pumping is not as effective for such
\nstations because two pumps operating together yield
\nonly slightly higher flows than one pump. If the
\npeak flow is to be achieved with multiple pumps in
\nparallel, the lift station must be equipped with at
\nleast three pumps: two duty pumps that together
\nprovide peak flow and one standby pump for
\nemergency backup. Parallel peak pumping is
\ntypically used in large lift stations with relatively
\nflat system head curves. Such curves allow
\nmultiple pumps to deliver substantially more flow
\nthan a single pump. The use of multiple pumps in
\nparallel provides more flexibility.
\nSeveral types of centrifugal pumps are used in
\nwastewater lift stations. In the straight-flow
\ncentrifugal pumps, wastewater does not change
\ndirection as it passes through the pumps and into
\nthe discharge pipe. These pumps are well suited for
\nlow-flow\/high head conditions. In angle-flow
\npumps, wastewater enters the impeller axially and
\npasses through the volute casing at 90 degrees to its
\noriginal direction (Figure 3). This type of pump is
\nappropriate for pumping against low or moderate
\nheads. Mixed flow pumps are most viable for
\npumping large quantities of wastewater at low head.
\nIn these pumps, the outside diameter of the impeller
\nis less than an ordinary centrifugal pump, increasing
\nflow volume.
\nVentilation
\nVentilation and heating are required if the lift
\nstation includes an area routinely entered by
\npersonnel. Ventilation is particularly important to
\nprevent the collection of toxic and\/or explosive
\ngases. According to the Nation Fire Protection
\nAssociation (NFPA) Section 820, all continuous
\nventilation systems should be fitted with flow
\ndetection devices connected to alarm systems to
\nindicate ventilation system failure. Dry-well
\nventilation codes typically require six continuous
\nair changes per hour or 30 intermittent air changes
\nper hour. Wet-wells typically require 12 continuous
\nair changes per hour or 60 intermittent air changes
\nper hour. Motor control center (MCC) rooms
\nshould have a ventilation system adequate to
\nprovide six air changes per hour and should be air
\nconditioned to between 13 and 32 degrees Celsius
\n(55 to 90 degrees F). If the control room is
\ncombined with an MCC room, the temperature
\nshould not exceed 30 degrees C or 85 degrees F.
\nAll other spaces should be designed for 12 air
\nchanges per hour. The minimum temperature
\nshould be 13 degrees C (55 degrees F) whenever
\nchemicals are stored or used.
\nOdor Control
\nOdor control is frequently required for lift stations.
\nA relatively simple and widely used odor control
\nalternative is minimizing wet-well turbulence. More
\neffective options include collection of odors
\ngenerated at the lift station and treating them in
\nscrubbers or biofilters or the addition of odor
\ncontrol chemicals to the sewer upstream of the lift
\nstation. Chemicals typically used for odor control
\ninclude chlorine, hydrogen peroxide, metal salts
\n(ferric chloride and ferrous sulfate) oxygen, air, and
\npotassium permanganate. Chemicals should be
\nSource: Lindeburg, revised edition 1995.
\nFIGURE 3 CENTRIFUGAL ANGLE-FLOW
\nPUMP
\nclosely monitored to avoid affecting downstream
\ntreatment processes, such as extended aeration.
\nPower Supply
\nThe reliability of power for the pump motor drives
\nis a basic design consideration. Commonly used
\nmethods of emergency power supply include
\nelectric power feed from two independent power
\ndistribution lines; an on-site standby generator; an
\nadequate portable generator with quick connection;
\na stand-by engine driven pump; ready access to a
\nsuitable portable pumping unit and appropriate
\nconnections; and availability of an adequate holding
\nfacility for wastewater storage upstream of the lift
\nstation.
\nPERFORMANCE
\nThe overall performance of a lift station depends on
\nthe performance of the pumps. All pumps have
\nfour common performance characteristics: capacity,
\nhead, power, and overall efficiency. Capacity (flow
\nrate) is the quantity of liquid pumped per unit of
\ntime, typically measured as gallons per minute
\n(gpm) or million gallons per day (mgd). Head is
\nthe energy supplied to the wastewater per unit
\nweight, typically expressed as feet of water. Power
\nis the energy consumed by a pump per unit time,
\ntypically measured as kilowatt-hours. Overall
\nefficiency is the ratio of useful hydraulic work
\nperformed to actual work input. Efficiency reflects
\nthe pump relative power losses and is usually
\nmeasured as a percentage of applied power.
\nPump performance curves (Figure 4) are used to
\ndefine and compare the operating characteristics of
\na pump and to identify the best combination of
\nperformance characteristics under which a lift
\nstation pumping system will operate under typical
\nconditions (flows and heads). Pump systems
\noperate at 75 to 85 percent efficiency most of the
\ntime, while overall pump efficiency depends on the
\ntype of installed pumps, their control system, and
\nthe fluctuation of influent wastewater flow.
\nPerformance optimization strategies focus on
\ndifferent ways to match pump operational
\ncharacteristics with system flow and head
\nrequirements. They may include the following
\noptions: adjusting system flow paths installing
\nvariable speed drives; using parallel pumps
\ninstalling pumps of different sizes trimming a pump
\nimpeller; or putting a two-speed motor on one or
\nmore pumps in a lift station. Optimizing system
\nperformance may yield significant electrical energy
\nsavings.
\nOPERATION AND MAINTENANCE
\nLift station operation is usually automated and does
\nnot require continuous on-site operator presence.
\nHowever, frequent inspections are recommended to
\nensure normal functioning and to identify potential
\nproblems. Lift station inspection typically includes
\nobservation of pumps, motors and drives for
\nunusual noise, vibration, heating and leakage, check
\nof pump suction and discharge lines for valving
\narrangement and leakage, check of control panel
\nswitches for proper position, monitoring of
\ndischarge pump rates and pump speed, and
\nmonitoring of the pump suction and discharge
\npressure. Weekly inspections are typically
\nconducted, although the frequency really depends
\non the size of the lift station.
\nIf a lift station is equipped with grinder bar screens
\nto remove coarse materials from the wastewater,
\nthese materials are collected in containers and
\ndisposed of to a sanitary landfill site as needed. If
\nthe lift station has a scrubber system for odor
\ncontrol, chemicals are supplied and replenished
\ntypically every three months. If chemicals are
\nadded for odor control ahead of the lift station, the
\n0
\n10
\n20
\n30
\n40
\n50
\n60
\n70
\n0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
\nDischarge (m3\/s)
\nHead (m)
\nSystem Curve
\nPump Curve
\nSource: Adapted from Roberson and Crowe, 1993.
\nFIGURE 4 PUMP PERFORMANCE CURVE
\nchemical feed stations should be inspected weekly
\nand chemicals replenished as needed.
\nThe most labor-intensive task for lift stations is
\nroutine preventive maintenance. A well-planned
\nmaintenance program for lift station pumps
\nprevents unnecessary equipment wear and
\ndowntime. Lift station operators must maintain an
\ninventory of critical spare parts. The number of
\nspare parts in the inventory depends on the critical
\nneeds of the unit, the rate at which the part normally
\nfails, and the availability of the part. The operator
\nshould tabulate each pumping element in the system
\nand its recommended spare parts. This information
\nis typically available from the operation and
\nmaintenance manuals provided with the lift station.
\nCOSTS
\nLift station costs depend on many factors, including
\n(1) wastewater quality, quantity, and projections;
\n(2) zoning and land use planning of the area where
\nthe lift station will be located; (3) alternatives for
\nstandby power sources; (4) operation and
\nmaintenance needs and support; (5) soil properties
\nand underground conditions; (6) required lift to the
\nreceiving (discharge) sewer line; (7) the severity of
\nimpact of accidental sewage spill upon the local
\narea; and (8) the need for an odor control system.
\nThese site and system specific factors must be
\nexamined and incorporated in preparing a lift
\nstation cost estimate.
\nConstruction Costs
\nThe most important factors influencing cost are the
\ndesign lift station capacity and the installed pump
\npower. Another cost factor is the lift station
\ncomplexity. Factors which classify a lift station as
\ncomplex include two or more of the following: (1)
\nextent of excavation; (2) congested site and\/or
\nrestricted access; (3) rock excavation; (4) extensive
\ndewatering requirements, such as cofferdams; (5)
\nsite conflicts, including modification or removal of
\nexisting facilities; (6) special foundations, including
\npiling; (7) dual power supply and on-site switch
\nstations and emergency power generator; and (8)
\nhigh pumping heads (design heads in excess of
\n200 ft).
\nMechanical, electrical, and control equipment
\ndelivered to a pumping station construction site
\ntypically account for 15 to 30 percent of total
\nconstruction costs. Lift station construction has a
\nsignificant economy-of-scale. Typically, if the
\ncapacity of a lift station is increased 100 percent,
\nthe construction cost would increase only 50 to 55
\npercent. An important consideration is that two
\nidentical lift stations will cost 25 to 30 percent more
\nthan a single station of the same combined capacity.
\nUsually, complex lift stations cost two to three
\ntimes more than more simple lift stations with no
\nconstruction complications.
\nTable 1 provides examples of complex lift stations
\nand associated construction costs in 1999 dollars.
\nTABLE 1 LIFT STATION CONSTRUCTION COSTS
\nLift Station
\nDesign Flowrate
\n(MGD)<\/p>\n
\nLift station operation and maintenance costs include
\npower, labor, maintenance, and chemicals (if used
\nfor odor control). Usually, the costs for solids
\ndisposal are minimal, but are included if the lift
\nstation is equipped with bar screens to remove
\ncoarse materials from the wastewater. Typically,
\npower costs account for 85 to 95 percent of the total
\noperation and maintenance costs and are directly
\nproportional to the unit cost of power and the actual
\npower used by the lift station pumps. Labor costs
\naverage 1 to 2 percent of total costs. Annual
\nmaintenance costs vary, depending on the
\ncomplexity of the equipment and instrumentation.<\/p>\n