The wastewater lift station in the municipality is old. Pumps are nearing the end of their usefulness, the controls require modernization, and the access hatch needs to be replaced. The concrete wet well is sturdy and solid.
Image credit: romtecutilities.com
Do you think the station should be completely demolished and rebuilt? Not necessarily. The more important issue is whether the existing infrastructure can support a modern pumping system without compromising availability, reliability or future capacity.
A thoughtfully designed retrofit of a pump station can help preserve important infrastructure and replace components that are no longer in compliance with operating requirements.
Start with the structure isn’t being replaced by anyone.
It’s costly and inconvenient to replace the wet well since it is submerged in the ground, linked to pipes, and is necessary for the collection of wastewater.
Retaining a concrete construction that is functional can reduce the excavation and construction.
But, any deterioration that occurs around the access hatch can complicate the decision. Romtec Utilities identifies wet well hatch replacement as a common retrofit requirement. Instead of affixing a hatch to cement that has deteriorated, replacing the whole top layer may be a better option. This method can be used to increase accessibility and the functionality of the structure, without the need to replace the entire wet well.
A More Powerful Pump Changes the Engineering
Imagine a neighborhood that has seen an increase in population since its first lift station was put in place. It’s possible that pumping system is no longer capable of handling the increased flows of wastewater.
The improvement of a pumping system could comprise higher horsepower equipment, but this cannot be done without considering the whole system. To get more powerful pumps, you may need to make changes to the discharge elbows or piping. It is also possible to change electrical controls and valves.
Engineers must also think about the hydraulic requirements of the system. This includes flow and the total dynamic pressure. A larger pump installed without reviewing these conditions can create problems in operation instead of resolving them. Planning for future expansion during your initial design process will enable you to expand later on.
Make sure that the water for waste is moving during construction
A wastewater pump station retrofit introduces a challenge that ordinary equipment replacement projects may not face: the station may need to remain operational throughout construction.
Even when contractors are working they continue to receive wastewater. According to the project it is possible that a temporary bypass pumping system may be necessary to maintain service as existing equipment is removed or new equipment is installed.
Romtec Utilities accepted this challenging task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project involved replacing two aging wastewater lift stations in the process of maintaining operation at the facility. The project was able to adapt to existing station footprints as well as operational requirements by using local-specific engineering and system for replacement that is packaged. This illustrates how the order of construction should be carefully considered before installation.
If replacing is the only alternative
Each station is not able to be rehabilitated. A seriously degraded wet well insufficient structural capacity or significant changes in hydraulic requirements could make the sewer lift station replacement more appropriate than changing the existing installation.
The decision must take into consideration structural condition, equipment compatibility, construction access along with service continuity and long-term operating requirements. Romtec Utilities begins retrofits and replacements by identifying components which are expected to stay and those that need to be replaced.
From there, the firm designs site-specific engineering solutions including preliminary designs, as well as budgetary estimates. Prefabricated components are also beneficial for organizing installation and reducing the number of on-site requirements.
The Project isn’t Over Until the Pumps Start
Modern lift stations must be able to function as an integrated system. Before returning the lift station to service, testing its startup and commissioning are a way to make sure that the pumps and controls as well as other equipment work in accordance with established specifications.
Manuals for maintenance and operation and also training for operators, are essential. Maintenance staff should be acquainted with the new equipment and operating procedures, in addition to the documents before taking charge of the station.
A successful retrofit helps preserve the value of infrastructure as well as addressing the weaknesses that forced modernization.
For facilities owners and municipal authorities this means looking beyond the immediate repair. The most successful project is one that integrates the new equipment into existing structures, ensures vital services throughout construction and also prepares the pumping system to last for years of continual operation.