- The division operates two wastewater treatment plants with a combined capacity of about 51.4 million gallons per day of maximum month average daily flow (MMADF) and 132 million gallons per day of peak hydraulic flow.
- One Class A Sludge Treatment Facility
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Treatment Process
Headworks
Final Clarifiers
Oxidation Ditch/Aeration
Effluent Handling
Returned Activated Sludge( RAS )
Sludge Handling
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| Wastewater Treatment Plant Improvements
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Currently (2005) there are two projects underway for improving wastewater management at the Lucas and North Regional Wastewater Treatment Plants. Those consist of the following improvements:
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- Expand the existing flow equalization basin (FEB) headworks to a capacity of 100+ million gallons per day (mgd), reconfigure the piping at the existing Pista-Grit equipment to reduce headloss, relocate the existing grit pumps to improve performance, and modify the Pista-Grit units to bring them to their rated capacities.
- Enclose the headworks and provide odor control.
- Abandon-in-place the original aerated grit removal facilities including the Parshall flume, mechanical bar screens and associated piping. Mechanical equipment that is determined to be in good condition during time of construction will be salvaged. Convert the aerated grit building into an operation building.
- Remove the existing mechanical equipment from the aeration basins and retrofit with fine bubble diffused aeration. Add bioselector cells at the aeration basins.
- Modify the sludge removal mechanism in the four existing clarifiers to add two additional sludge scrapper arms to each mechanism. Evaluate the need to replace the existing mechanism motors with higher horsepower motors to accommodate the additional sludge arms.
- Add on additional secondary clarifier and scum removal pump.
- Allocate land for potential future construction of additional secondary clarifiers, filters, and tanks required to meet anticipated future nitrification, denitrification, total suspended solids (TSS) removal, and organic removal requirements.
- Reconfigure the piping to the FEBs so that each basin may be isolated for cleaning. Provide water cannons to assist in cleaning the basins.
- Construction of an ultraviolet (UV) light facility as an alternative means of disinfection. The UV system eliminates any concerns the treatment plant has regarding compliance with Title III regulations for chlorine and sulfur dioxide.
- Upgrade the Supervisory Control and Data Acquisition (SCADA) system to be compatible with the City’s new SCADA system.
- Provide new return activated sludge (RAS) pumps associated with the new clarifier (item 5).
- Provide a parallel 48-inch diameter transmission pipe from the headworks at the FEBs to the new bioselector to reduce headloss at high flows.
- Construct a wet-weather flow treatment facility.
- Provide paving, grading, drainage, structural and electrical facilities as required to accommodate the listed modifications.
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| North Regional WWTP Upgrades
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- Perform structural repairs to the FEBs including replacing the failing banks and subsurfaces on FEB3, developing a method to seal the joints at all the FEBs or installing waterstops, and providing a cleaning method for the FEBs to reduce the potential for odor generation during the cleaning process.
- Construct a new headworks prior to the FEBs and third treatment train.
- Construct a third oxidation ditch to provide reliable service during maximum monthly flows (Class 1 reliability) and sufficient treatment capacity to allow one treatment train to be out-of-service for cleaning.
- Provide a bioselector structure or anoxic zone in the oxidation ditches 1 through 3 to enhance treatment through the development of desirable bacteria and reduction of filamentous bacteria.
- Provide access to gates at the existing headworks through the addition of grating over the channels and handrail.
- Provide a new junction box from the FEB overflow to direct flow to the new train or by-pass the FEBs.
- Construct an UV light facility as an alternative means of disinfection. The UV system eliminates any concerns the treatment plant has regarding compliance with Title III regulation for chlorine and sulfur dioxide.
- Modify the existing effluent pump station header to eliminate hydraulic restrictions and construct a new 30-inch diameter effluent pipe parallel to the existing pipe to provide for peak flow discharge capacity.
- Upgrade the SCADA system to be compatible with the City’s new SCADA system.
- Replace wiring and conduit at the plant as required.
- Raise the existing switchgear to provide flood protection.
- Provide drainage improvements throughout the plant, particularly to the existing gravity drainage system.
- Modify the existing effluent pump station and construct a new effluent pipe parallel to the existing pipe.
- Provide paving, grading, drainage, structural and electrical facilities as required to accommodate the listed modifications.
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| Both of the plants have essentially been rebuilt from the ground up, at a cost of approximately $86 million. These projects are nearing completion, and involve improvements in virtually every physical aspect of the treatment processes, including the screening, aeration, clarification, disinfection and pumping systems, in addition to electrical, instrumentation (SCADA) and other improvements. Both plants have converted from chemical to ultraviolet light disinfection, eliminating all risks of airborne releases of chlorine and sulfur dioxide.
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| System-wide SCADA system
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As part of the plant improvement program, a System Control and Data Acquisition (SCADA) system is being implemented for the collection system, including key lift stations. The system will automate much of the facilities” operations and will enable the City to significantly improve real-time operations control during and immediately after wet-weather events throughout the system.
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| Flow Equalization Basins
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Purpose:
To hold the excessive wet weather flow until the Lucas and North Regional Wastewater Treatment Plant can effectively treat the wastewater without hydraulic and/or organic overload. The flow equalization basins are located at the Lucas and North Regional Wastewater Treatment Plants.
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| Flow Equalization Ponds
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| Purpose:
To hold the excessive wet weather flow until the Lucas Wastewater Treatment Plant, can effectively treat the wastewater without hydraulic and/or organic overload. The flow equalization ponds consist of both the Huntington Park and West Shreveport facility.
Operation:
If an excessive wet weather event occurs, and the flow exceeds the effective treatment capacity of the Lucas plant, the operator in charge notify the sewer lift personnel to activate the equalization ponds. Once the event has stabilized, the flow is then diverted back to the Lucas Wastewater Treatment Plant, via the Wallace Lift Station, for normal operation.
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| Laboratory
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| The laboratory facilities contain some of the finest laboratory equipment presently available. The lab is staffed by approximately five college Science graduates and a supervisor; they operate on an eight hour basis. The laboratory is used to analyze the wastewater discharges and industries throughout the City of Shreveport.
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