Sanitary Lift Stations
Contents
1. be provided for parking of maintenance staff and service vehicles Fencing All industrial lift station sites shall be fenced Fencing in residential areas may be required as determined by Aquatera The fence shall as a minimum have a double roller gate for entry of vehicles and equipment and additionally a man gate may be required Any gates shall be lockable and the developer shall equip them with an Aquatera lock Fences shall typically be zinc coated industrial grade steel chain link security type Fence height shall be 1 83 m in overall height complete with three strand barbed wire overhang installed above the 1 83 m height Where dictated by esthetic reasons an architectural fence providing a similar level of security may be required Site Grading The pumping station site shall be designed with adequate grade so that surface water drains freely away from the building and no ponding of water occurs adjacent to the building entrances or within the site Site elevations shall be established such that the facility shall not be subject to flooding due to runoff flows or ponding under any conditions of rainfall or 2015 SECTION 10 Page 17 of 20 10 17 4 10 17 5 10 18 10 18 1 10 18 2 10 18 3 CZ AQUATERA DM Section 10 Sanitary Lift Stations runoff from snowmelt Landscaping and Aesthetic Considerations As a minimum lift station sites shall be paved with asphalt inside the fenced area Where the proximity to res2. located so that it cannot be flooded under any foreseeable circumstances Pressure Gauges Taps with shut off valves suitable for quick connect pressure gauges shall be provided on each suction and discharge The location of these taps shall be such that the locations are suitable and easily accessible i Gauge taps shall be installed on the discharge side of all pumps and on the main discharge to the force main The gauge taps are required to permit the determination of operating pressures of the pumps for comparison with pump curves and identification of any change in operating pressure that could be indicative of an operational problem Pump discharge gauge taps should be located between the pump discharge and the discharge check valve ii Gauges should be a compound pressure vacuum type equipped with a diaphragm seal and isolation valves Gauges provided for discharge lines shall be liquid filled with a maximum range of at least twice the operating pressure Gauges shall be stainless steel Maintenance and Operation Provisions Pump and Equipment Removal i Permanent hoist equipment and access hatches shall be provided to permit the removal and or replacement of any pieces of station equipment Hoists and beams should if possible allow for placement of equipment onto service vehicles without double handling the equipment or use of mobile cranes ii Appropriate vehicle access and adequate access hatches must be provided to allow
3. switch utility power fail pump fault fail to run level transducer fault and high low level alarms e All SCADA equipment software shop drawings schedule and the site specific program files shall be reviewed by Aquatera prior to installation The supplier shall conduct a bench test for all equipment to be installed The bench test results shall be documented and provided to Aquatera All SCADA equipment software as built drawings with schedule site specific program files license and warranty agreements and all relevant documentation shall be transferred to Aquatera in hardcopy and electronic file format prior to CCC release Pump Valve and Piping Arrangement Pump and Discharge Header Arrangement Two or more pumps shall be connected in a parallel arrangement to a common header which must be located within a control building or dry well above ground such that the isolation and check valves are accessible for operation and maintenance Consideration shall be given to allow access to the isolation and check valves that does not require confined space entry Pump Removal Pumps are to be connected such that when any pump is removed for servicing the remaining pump s will remain operational Submersible pumps shall be removable and replaceable without the need for 2015 SECTION 10 Page 10 of 20 10 12 3 10 12 4 10 12 5 10 12 6 CZ AQUATERA DM Section 10 Sanitary Lift Stations dewatering the wet well or for
4. RA DM Section 10 Sanitary Lift Stations cooling net positive suction head priming requirements and vortex control Wet wells must be sized small enough to minimize the total retention time the time sewage is held in the wet well and any rising forcemain and yet be large enough to control the frequency of pump starts The maximum retention time in the wet well should not exceed thirty 30 minutes for the design minimum flow rate anticipated when the contributing area is fully developed Total retention time in the wet well and forcemain shall be kept to a minimum generally less than four 4 hours to avoid anaerobic fermentation and the resultant production of odorous hazardous and corrosive gases Otherwise provisions must be made to control anaerobic conditions It is desirable to have a wet well with sufficient active volume so that all sewage within the discharge forcemain will be replaced during one pumping cycle especially if sags exist in the forcemain profile Wet wells shall be sized large enough to maximize pump life by decreasing the frequency of pump starts However in the interest of limiting excessive detention time wastewater pumping stations will inherently be subject to relatively high frequencies of switching cycles Exceeding a frequency of 12 starts per hour for motors above 30 kw increases the cost of switch gear and motor maintenance and the reliability and life of the machinery and electrical components
5. a Cs AQ 10 1 10 2 10 2 1 10 2 2 10 2 3 10 3 10 3 1 10 3 2 UATERA WATER EARTH INNOVATION 2015 SECTION 10 SANI TARY LIFT STATI ONS GENERAL Aquatera encourages consistency and standardization in the design and construction of wastewater pumping stations The standardization is intended to promote designs that facilitate the economical construction operation and increased reliability Standardization in equipment and controls will reduce the inventory of spare parts allow interchangeability and promote safe and efficient operation and maintenance LOCATI ON Proximity to Other Land Uses Special consideration shall be given to the location of wastewater pumping stations relative to existing or proposed adjacent development in order to minimize the aesthetic impacts in terms of visibility odor and noise The location of wastewater pumping stations in the immediate proximity of school sites and playgrounds shall be avoided if possible Safety and security measures are to be addressed in such cases Flood Proofing Pumping stations are to be located outside of the limits of any area subject to surface ponding or inundation by surface water flow during major runoff events to prevent flooding so that they are accessible in all weather conditions Vehicle Access Wastewater pumping stations must be located so as to be readily accessible by road or permanent paved trail which shall be constructed to the
6. able back up points Alternate route of temporary pumping elevation and length of temporary pumping and type of equipment required Structural Drawings All valves air releases on site and forcemain to include survey co ordinates ot a E e o N 2015 SECTION 10 Page 18 of 20 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations Station Data 1 Pump motor name plates and impeller size design L s for all pumps 2 Storage time and average flow L s peak flow L s 3 Auxiliary equipment data 4 Wet well control levels starts stops high and low levels 5 TDH 6 All fuse sizes and locations 10 18 4 The manual shall also include complete equipment manufacturer s operation maintenance service and repair instructions and complete parts lists for all mechanical and electrical equipment including but not limited to all control diagrams and schematics with wires individually numbered and identified Each set shall be firmly bound in a hard covered binder and include test results and calibration of all equipment from commissioning and testing conducted by a professional engineer for the Developer prior to application of a CCC 2015 SECTION 10 Page 19 of 20 73 AQUATERA Reviaiona DM Section 10 Sanitary Lift Stations Details CLP AQUATERA INCOMING SEWERS WASTEWATER PUMPING STATION E Approved by Timothy Lau P Eng 10 01 12 07 12 Checked by Brad Va
7. anitary system 2015 SECTION 10 Page 4 of 20 10 6 5 10 6 6 CT AQUATERA DM Section 10 Sanitary Lift Stations Overflows to Storm Drainage Systems Overflows to storm drainage sewers storage facilities natural water courses or surface outfall points will require special justification and will be subject to approval from Alberta Environment and The City of Grande Prairie before acceptance by Aquatera Overflows to storm services are preferred as opposed to overflows to watercourses Prevention of Backflow for Overflows Overflow connections shall be provided with suitable means to prevent backflow from the overflow into the pumping station 10 7 STAGING OF WASTEWATER PUMPING FACILITIES 10 7 1 10 7 2 10 7 3 10 7 4 10 8 Where warranted due to economic considerations or to accommodate extended periods of development of the contributing areas the provision of pumping capacity and or the construction of a wastewater pumping station may be staged appropriately Where such staging is proposed all stages are to be defined and related to the anticipated development scenario for the contributing area A plan of action is to be established as part of the initial design to define the process for the implementation of future stages The plan should consider continuity of service the responsibility and financial arrangements for future stage implementation and the most cost effective method for implementing the capacity c
8. compartment within a single building to house the wet well Brick work or siding for buildings shall be 240 Buff or an equivalent color approved by Aquatera Brick work shall be full split face Brick work shall have two 2 coats of clear sealant applied to the outside face only Building shall be insulated with an R 20 factor for walls and an R 40 factor for roofs Interior walls shall be painted Battleship Grey color 848482 Concrete floors shall be treated with Lithochrome color hardener in Platinum Grey color A 57 or an equivalent color approved by Aquatera Roofs flashing soffits downspouts shall be color QC8228 Metro Brown or an equivalent color approved by Aquatera Drain spouts shall have splash pads installed under the outlet Roofs shall be equipped with ice racks around the perimeter of the roof Lift stations with buildings shall have a floor drain in the control room and Shall be tied into the wet well Discharge of floor drains shall not drain on top of the pumps ladders rail systems or in a configuration that would drain onto an operator working within the wet well Floors shall slope toward the floor drains Piping within the lift station shall be labeled and color coded Sanitary pipes within the lift station shall be painted Green color 7581 The Back Nine Potable water pipes shall be painted Blue color 7358 Hidden Springs Gas pipes shall be painted Yellow color 7909 I
9. e manufacture s experience and history in the design and selection of pumps for raw sewage use Lift Station shall be designed with Flygt Pumps equipped with flush valves as this is the most common pumps in Aquatera s lift stations Alternate pump selection would require that a present worth analysis be undertaken and approved by Aquatera Pump Electrical Requirements Main pump motors shall operate at 600 volt 3 phase power Contact Aquatera for Design Guidelines for Electrical and Control Systems for Sewage Lift Stations for details of electrical power panels and connections Lift Station Electrical Requirements Inlet if possible and outlet flow meter flow rate and totalizer such as ABB ProcessMaster or ABB WaterMaster Soft starter and Across the line starter option with pilot lights run fault hour meters amp meter and HOA switch such as EATON S811 or AB SMC Flex Level transmitter with level switches backup option Low Level Stop Lead Start Lag Start and High Level such as MultiRanger 100 200 XPS 15 PMC Versaline VL2000 and Flygt level switches Note Transducer and level switches cables shall have quick connectors located in a non classified area Pumps shall have Plug and Receptacle on cable Such as STAHL SolConex or CES Series Backup generator shall be natural gas with louver controls fresh air outside vent and re circulate and automatic transfer switch Such as Belimo modulating actuator and Johnson c
10. eam entering the wet well should be avoided to prevent entrained air from reducing pump performance or causing loss of prime Provisions necessary to address this may include drop tubes inside wet wells of small facilities grade adjustments or a drop manhole upstream of the pumping station However inlet sewers shall not enter the wet well at an elevation lower then the normal high liquid level for the design capacity flow rate Inflow Shut Off Provisions An inflow shut off valve shall be provided on the inlet to the wet well so that inflow to the wet well can be stopped Shut off valves or slide gates should be installed in the first manhole upstream of the pumping station The shut off equipment shall be of a type and materials for raw sewage service The installation of shutoff devices within the wet well is not recommended unless there are no alternatives Under these circumstances provisions must be made for operating them without entry into the wet well WET WELL SI ZE AND DETAIL Size Considerations i Wet wells are to be of adequate size to suit equipment space operator access requirements and active volume considerations ii To minimize dead storage volume the depth from the pump off level to the floor of the wet well shall be kept to an acceptable minimum The required depth will be dictated by suction pipe inlet conditions pump manufacturer s requirements for submergence or 2015 SECTION 10 Page 6 of 20 CZ AQUATE
11. equivalent structure of the adjacent roadway PUMPI NG STATI ON CONFI GURATI ON REQUI REMENTS Lift Station shall be designed with wet well only configurations for pumping stations Wet well dry well configurations may be considered in exceptional circumstances The wet well submersible pump configuration is preferred for all facilities 2015 SECTION 10 Page 1 of 20 10 3 3 10 3 4 10 3 5 10 4 10 4 1 10 4 2 CZ AQUATERA DM Section 10 Sanitary Lift Stations due to the relatively low capital cost Where technically viable options exist in the choice of the type of pumps or in the station arrangement a present worth analysis shall be undertaken to determine the most cost effective equipment and arrangement including but not limited to the following factors e Cost of the Facility and its life e Energy costs over the life of the facility Life and replacement cost of the pumping equipment including ancillary equipment switch gear lifting and ventilation equipment The cost of operation and maintenance Reliability Safety Local availability of repair services Flood proofing Nuisance to residents of adjacent homes or users of parks facilities and developments The facility as a possible source of contamination to the environment e Compatibility with existing pumping stations units The design is to address the required functional lifetime of the facility structure This is deemed to be fifty 50 year
12. facilities Suitable equipment shall be installed to provide for continuous ventilation at a minimum rate of six 6 air exchanges per hour in each of the wet well and dry well areas Completely separate systems are required for each well and there will be no interconnection between the wet well and dry well ventilation systems ii Fresh air heated and thermostatically controlled shall be forced into each area at a point 150 mm above the floor in dry wells and 150 mm above the high water level in wet wells and exhausted at higher levels In wells with a depth greater than 4 5 m multiple inlets and outlets shall be considered in the design iii Increased ventilation on access Consideration shall be given to the provision of automatic controls to increase ventilation rates to 20 30 air changes per hour interconnected to turn on with the light switches and door switches in addition to the continuous ventilation requirements iv Provision shall be made to detect and actuate an alarm if the ventilation system should fail A local alarm indicator noticeable prior to entering the station but not noticeable to the general public is required A volume control buzzer and red beacon on the inside of the building visible as soon as the doors are opened is acceptable This alarm shall also be connected to the overall alarm system for the station V Provisions for back up ventilation to wet wells Provision shall be made for ventilation of we
13. for the use of mobile exterior cranes as required by Aquatera iii For wet well pump installations the provision and arrangement of lifting equipment shall be such that the necessity for personnel to enter the wet well for removal of equipment is minimized or 2015 SECTION 10 Page 13 of 20 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations eliminated iv Lifting equipment shall have sufficient capacity to handle the heaviest loads of equipment based on ultimate design and shall include allowances for dynamic forces due to load shifting The capacity of all lifting equipment shall be clearly posted on the equipment Eyebolts in the walls and ceilings if required shall be provided for rigging chain hoists or come alongs V Electrical connections for pumps shall be STAHL wall mounted explosion proof quick connects or an equivalent approved by Aquatera 10 14 2 Access into Station Structures i Suitable and safe means of access shall be provided for all equipment requiring inspection maintenance and to the wet well for inspection and cleaning ii Stairways and ladders shall comply with applicable legislation All stairs shall be of a non skid type For wet wells less than 10 7 m in depth access shall be provided by means of an aluminum ladder Wet wells in excess of 10 7 m shall have access provided by means of an aluminum stairs A platform shall be installed 1 5m above the high water level iii Access to wet wells
14. hanges A modular approach to the arrangement of structural components and or pumping units may facilitate staging and should be reviewed as part of the design Where the staging of a lift station includes staging of the pumps a mixer shall be installed in the wet well and baffles shall be installed in the unused portion of the wet well Interim Wastewater Pumping Stations Design Criteria Relaxation of the criteria for design and construction of temporary pumping stations may be permitted if approved by Aquatera in writing DETAILED DESIGN FOR WASTEWATER PUMPING STATIONS Refer to standard drawing 10 1 for typical arrangement and components of wastewater pumping stations 2015 SECTION 10 Page 5 of 20 10 9 10 9 1 10 9 2 10 9 3 10 9 4 10 10 10 10 1 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations WASTEWATER INLET SEWER Single Sewer Entry to Wet Wells Only one sewer connection shall be provided into a wet well to convey sewage from the contributing collection system Collection Manhole If more than one sewer enters the site or is required to be connected to the pumping station a collection manhole shall be provided as a junction point for all incoming sewers Appropriate stubs shall be provided for future connections Only a single connection is to be made from the collection manhole to the wet well of the pumping station Inlet Sewer Elevation Excessive entrainment of air into the flow str
15. idential areas public lands or other uses dictates the need for additional landscaping to conceal the facility and or to make it blend into the surroundings or to enhance the appearance these requirements shall be included as part of the facility design Additional landscaping requirements may include but not limited to planting of trees shrubbery or other architectural treatment of the site Signage All pumping facilities shall have as a minimum 1 one 600 six hundred mm by 1200 twelve hundred mm sign The sign shall have Aquatera s registered logo on it only No reference on the signage should indicate a pumping station The sign shall also include Aquatera s phone number 780 538 0348 Operating Maintenance and Service Manual As part of the design of a waste water pumping station the design engineer shall prepare and provide an Operating Maintenance and Service Manual for the facility Two 2 complete copies and one 1 digital copy of the manual are to be provided prior to the transfer of the facility operation to Aquatera This Shall be at the time of the approval of a construction completion certificate CCC Contact Aquatera for a reference template for the manual The manual shall include As builts drawings of the facility Size length and details of the forcemain Available main power and fuse size Actual capacities of pumps and rates of flow throughout the day Lowest services on the system and most prob
16. ll C E T Scale Drawn by Scott Walls Permit Number File Number P09242 11009 Page 20 of 20
17. nca Gold PUMPING CAPACITY REQUIREMENTS Design Capacity Pumping equipment shall be selected with capacity in excess of the maximum expected flow as determined by established engineering practice In all cases the design capacity flow rate for a wastewater pumping station shall exceed the expected maximum flow rate as determined in accordance with Section 9 of Aquatera s Design Standards Mechanical Redundancy A minimum of two 2 pumps are required for each pumping station and 2015 SECTION 10 Page 3 of 20 10 6 10 6 1 10 6 2 10 6 3 10 6 4 CZ AQUATERA DM Section 10 Sanitary Lift Stations three 3 are preferred Generally these pumps shall be identical and interchangeable Where only two 2 pumping units are provided they shall each be of the same pumping capacity and each unit operating independently shall be capable of pumping at the design capacity flow rate for the station under the service conditions Where three 3 or more pumping units are provided they shall have pumping capacity such that with the largest unit out of service the remaining units operating in parallel are capable of pumping at the design capacity flow rate for the station under the service conditions OPERATIONAL RELI ABI LI TY EMERGENCY BACK UP PROVISIONS The design of wastewater pumping facilities must identify and anticipate all events that may affect the functioning of the facility Provisions must be made to mitigate the con
18. of corrosion resistant materials ii All aluminum doors or hatches are recommended for access to the wet wells Installation of electrical equipment and wiring within the wet well is to be avoided unless it is essential that it be located in the wet well 10 10 5 Electrical All electrical equipment and wiring located within the wet well shall be Class 1 Category 2 as per the Canadian electrical Code 10 11 Pumps 10 11 1 Pump Selection Considerations i Submersible pumps are preferred for all situations Pumps are to be removable and replaceable without dewatering the wet well or requiring personnel to enter the wet well All pumps in a lift station Shall be identical and interchangeable ii Pump impellers shall be of a non clog design and be capable of passing spherical solids of up to 75 mm in diameter iii Pumps are to be selected which provide optimum efficiencies at actual operating points The power rating of the motor should not be exceeded by the pump at any operating condition on the characteristic curve for the pump selected iv Flush valves recirculation pipes or mixers shall be provided for aeration and suspension of grit and solids in the wet well V Pump selection shall also take into account the availability of local 2015 SECTION 10 Page 8 of 20 CZ gt AQUATERA 10 11 2 10 11 3 10 11 4 vi DM Section 10 Sanitary Lift Stations repair service Pumps selected shall also take into account th
19. ontrols temperature controller Building High Low temperature alarm SCADA Requirements SCADAPack compact Smart RTUs should be used in combination with SCADAPack Vision panel mounted operator interface terminal for onsite SCADA system On site SCADA system should be housed inside a pre fabricated CSA approval electrical panel equipped with UPS battery backup 2015 SECTION 10 Page 9 of 20 10 12 10 12 1 10 12 2 CZ AQUATERA DM Section 10 Sanitary Lift Stations e On site SCADA system should be compatible with ClearSCADA server through a preferable Ethernet communication or phone landline with phone stick if sharing a common phone line e On site parameters that need monitoring and or controlling by SCADA system should be included but not limited to pump status wet well sewer level with time stamp pump start stop adjustable set points flow rate flow totalizer intruders air quality generator activity status and alarms e On site operator display interface should be included but not limited to pump status wet well sewer level with time stamp pump start stop adjustable set points flow rate flow totalizer intruders air quality generator activity status and alarms e SCADA system alarms should be independent from the ProTalk alarms that should serve as backup to each other e SCADA alarms that shall be included high low temp air quality H2S CO 02 and Flammable generator fault fail to run transfer
20. p dispenser e towel dispenser ii Sufficient additional space to accommodate the following e Maintenance of fixed pumping station components e Storage for spare parts tools and manuals e Plan table and chair iii Safety Equipment as specified by Aquatera or as a minimum the following e DBI Sala 3D Ring harness Model 1102008 e DBI Sala lift work winch Model 8102001 with stainless steel cable 2015 SECTION 10 Page 16 of 20 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations e DBI Sala Sealed Blok Self Retracting Lifeline model 3400108 e DBI Sala Davit arm and flush mounted davit base model 8000059 and Model 8000055 or equivalent e Fire Extinguisher Dependant on the depth of the wet well the model number may change but equipment shall still conform to these standards 10 16 10 17 10 17 1 10 17 2 10 17 3 Sump Pump Dry wells shall be equipped with a sump and sump pump to deal with leakage or seepage The sump pump is to discharge into the wet well at a point above the maximum high water level A check valve shall be provided in the discharge pipe to preclude backflow of wastewater into the sump Site Requirements Vehicle Access A minimum 4 5 m wide paved road shall be provided to the site with extensions as appropriate to provide maintenance vehicle access to the facility electrical transformers and for the removal and delivery of other station equipment Paved parking shall also
21. personnel to enter into the wet well Pump Suction Arrangement Each pump shall have its own individual intake and or suction connection to the wet well Suction Crossover wet well dry well lift stations In wet well stations a full sized valve cross over pipe shall be installed connecting the individual suction pipes and shut off valves shall be placed on the pump suction pipes between the crossover connections and the pumps The piping and valve arrangement shall be such that it will permit the isolation of any individual pump for maintenance and or removal Provision for Back Flushing Piping and valves shall be provided to back flush each pumping unit and its suction connection using the discharge flow from another pump directed through the discharge of the unit being flushed Piping and Valve Requirements i Minimum size of piping The minimum diameter of piping for all pump suction and discharge piping shall be 100 mm nominal Piping shall be sized such that flow velocity will not exceed 1 8 m s in suction piping or 3 5 m s in the discharge header within the pumping station Flow velocities should not be less than 0 75 m s to maintain solids in suspension Discharge piping should be as large as possible while still maintaining the minimum velocity for scouring ii Pipe Materials All piping within the wastewater pumping station shall be of stainless steel materials All flange bolting within the wet well shall be stainless
22. r or replacement A forcemain isolation valve shall be included on the main discharge pipe where it connects to the discharge forcemain before leaving the facility This is to allow for isolation of the forcemain from the pumping station Bypass Provisions A tee connection with a shut off valve on the branch shall be provided on the main discharge pipe within each pumping station upstream from the Forcemain Isolation Valve The arrangement is to allow for either bypassing the station using auxiliary pumping equipment or bypassing the forcemain and pumping to an alternate outlet line The unconnected end of the tee connection must be orientated to face towards an access hatch or entryway to facilitate the connection of the auxiliary pump discharge or outlet line Provisions for Removal of Valves and Equipment Provisions shall be made in the piping for removal of all valves and equipment Appropriately located vent and drain valves shall be provided to permit drainage of all piping to facilitate removal of valves and equipment 2015 SECTION 10 Page 12 of 20 10 13 10 13 1 10 13 2 10 14 10 14 1 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations Pump Control and Instrumentation Requirements Contact Aquatera for information relating to the Design Guidelines for Electrical and Control Systems for Sewage Pumping Stations Control panel and Electrical equipment The control panel and electrical equipment shall be
23. s unless Aquatera specifically approves a different lifetime The pumping equipment shall be assumed to receive a major overhaul involving renewal of the wearing components at seven 7 to ten 10 year intervals dependent on service conditions The analysis shall bear in mind that the pumping units may require replacement every 15 years This may be as a result of obsolescence or other reasons BUILDING REQUIREMENTS A building will be required at all pumping stations to house all electrical and control equipment Permanent pumping stations may require additional space for maintenance storage hand washing facilities and office space office space refers to a desk or plan table with a chair These requirements may be reduced for temporary lift stations or based on the size and location of the lift station with Aquatera s written approval All heating and ventilation equipment and valves are to be housed in the building or a dry well The building or dry well shall be completely isolated from the pumping station wet well and provision for access to the wet well shall only be from the outside through separate 8 foot high double doors or access hatches with approved locking devices 2015 SECTION 10 Page 2 of 20 CZ gt AQUATERA 10 4 3 10 4 4 10 4 5 10 4 6 10 4 7 10 4 8 10 4 9 10 4 10 10 5 10 5 1 10 5 2 DM Section 10 Sanitary Lift Stations Pumping stations may require a separate building or separate
24. sequences of failure of the facility by any mode so as to prevent property damage the endangerment of public health or any environmental damage Power Supply Reliability Provisions a Independent power supply sources Whenever feasible the electric power supply to the facility is to be provided from two or more independent distribution sources b Emergency stand by power In cases where a redundant electrical power supply in not feasible or available provision of an on site installed emergency power equipment is required Emergency power equipment shall be natural gas fired unless otherwise approved by Aquatera Alarm Telemetry General requirements Automated remote sensing and telemetry equipment shall be provided at each wastewater pumping station This equipment shall provide for the detection of the status of selected operating conditions and transmission of appropriate alarms to the monitoring facilities established and operated by Aquatera Generally this equipment shall be Pro Talk plus with battery backup and Allen Bradley PLC complete with UPS or an equivalent approved by Aquatera Overflow Connections In anticipation of the potential operational failure of a wastewater pumping facility and its backup provisions the feasibility of providing a gravity overflow is to be evaluated The elevation and hydraulic capacity of overflow connections are to be optimized to minimize the risk of basement flooding due to a backup in the s
25. shall not be from dry wells iv Doors and access hatches shall be equipped with suitable locking devices V For all entry hatches non protruding extension ladders shall be provided The extension ladders shall be located far enough from the walls to be able to be pulled up through the access opening and extend 1 0 m above the opening vi Access hatches located outside shall be sealed and have sufficient overhang to prevent rainwater inflow Odor tight aluminum hatch covers shall be used vii Access hatches to wet wells shall be Syracuse Castings Top Mounted Safety Grate System Weather Tight Heavy Duty H20 aluminum hatches or an equivalent approved by Aquatera 10 14 3 Lighting 2015 SECTION 10 Page 14 of 20 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations i Adequate lighting shall be provided for the entire facility The light fixtures shall be either vapor proof fluorescent for dry wells and or explosion proof incandescent for wet wells Emergency backup lighting shall also be provided ii Wet well lighting shall be portable and retractable and shall be arranged to be maintained from outside of the wet well iii Exterior lighting shall be provided to illuminate all building entrance areas entrance hatches and outside equipment Exterior lighting shall be designed so as to not create a nuisance to any nearby developments 10 14 4 Ventilation i Forced mechanical ventilation is required at all waste water
26. steel Buried pipe under the facility and within the excavation zone of the pumping facility shall be a minimum of standard wall welded steel with yellow jacket exterior and cement or epoxy coated interior or galvanized pipe with polyken tape wrapped exterior and Cathodic protection iii Pipe Pressure Rating Pressure rating for piping within the pumping facility shall suit the service requirements but shall also have a minimum pressure rating of 900 kpa 2015 SECTION 10 Page 11 of 20 10 12 7 10 12 8 10 12 9 10 12 10 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations Check Valves i Pump Discharge A check valve shall be installed on the discharge line between each pump and isolation valve These check valves shall not be mounted in a vertical position When vertical mounting of a check valve is necessary then the check valve shall not be of the flapper type ii Bypass Tee A check valve shall be installed after the bypass tee connection shut off valve to prevent backflow into any connected auxiliary pump This valve may be mounted vertically if necessary iii Check valve types Check valves shall be supplied with external levers and spring and limit switches to indicate and prove the valve opening Isolation Valves Shut off valves shall be included on the discharge lines from each pump between the check valve and discharge header This shall allow isolation of each pumping unit and check valve for repai
27. t wells using portable ventilation equipment in case of failure of the permanent on site ventilation 2015 SECTION 10 Page 15 of 20 10 14 5 10 15 10 15 1 10 15 2 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations Balancing Report For stations with new or refitted ventilation systems a balancing report is required signed by a professional engineer indicating measured ventilation flows and actual air change rates This will be forwarded by the Engineer to the Aquatera Project Engineer and posted in the station Heating Heating systems shall be designed so as to minimize heating costs Consideration shall be given to the use of high efficiency furnaces or boilers and the provision of heat recovery units to recover waste heat from exhausted air The entire facility shall be designed taking into account energy conservation Water Supply A potable water supply complete with a sufficient length of 50 mm hose shall be provided for the cleaning of floors pumps and other equipment There shall be no physical connection that might under any circumstances cause contamination of the potable water supply Backflow prevention and cross connection control shall comply with the most current Provincial and City of Grande Prairie plumbing regulations Provisions for Operating Personal in Permanent Pumping Stations i Hand washing facilities will be required that includes at a minimum the following e a large sink e soa
28. will decrease Accordingly sufficient storage between switching levels should be provided to limit the number of pump starts normally to 6 per hour with pump alternation and 12 per hour with the standby pump inoperative The manufacturer s recommendations with regard to the allowable frequency of pump starts for the specific size and type of motor are to be satisfied 10 10 2 Wet Well Shaping and Benching Wet wells shall be arranged and benched to limit dead spaces were solids can accumulate and to provide smooth uniform unobstructed flow to the pump suction influence zones Wet well floors should have a minimum slope of 1 1 to a hopper type bottom The horizontal area of the hopper type bottom should be no larger than necessary for the proper installation of the pump or suction pipe The cross sectional area and shape of the wet well above the benching is to be constant or increasing from the bottom towards the top 2015 SECTION 10 Page 7 of 20 CZ gt AQUATERA DM Section 10 Sanitary Lift Stations iii The critical flood line shall be permanently marked on the walls of the wet well 10 10 3 Vortex Prevention Suction elbows baffle plates vortex breakers or drop tubes are to be provided as required 10 10 4 Corrosion Considerations Wet Well i All bolts nuts other fasteners and piping used in the wet well areas shall be stainless steel All Supports brackets gratings ladders and other structures shall be
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