A municipality is home to an aging wastewater lift station. The pumps are coming to the expiration date of their service life span, the controls require modernization as well as the access hatch is deteriorating. The concrete wet well is solid and structurally sound.
Should the station be totally destroyed? Not necessarily. The more important question to ask is whether or not the current infrastructure can accommodate pumps that meet the latest standards, without compromising reliability or future capacity.
Image credit: romtecutilities.com
A carefully engineered pump station retrofit can preserve valuable infrastructure while replacing components that no longer meet operational requirements.
Begin with the Structures that nobody Would Like To Replace
Wet wells are often the most expensive and difficult component to replace, as they are underground and connected to existing pipes, and vital to wastewater collection.
The concrete structure can be retained to make it easier to dig and build.
However, damage to the access hatch can complicate the choice. Romtec Utilities says that wet well hatches can be replaced in retrofits. Instead of gluing a hatch to cement that is degrading replacing the whole top layer can be more durable. This could increase the accessibility to the structure and extend its use, without the need to completely rebuild the wet well.
A new pump improves the design
Imagine a neighborhood that has grown substantially since its first lift station was put in place. The pumps that are in place may not be adequate to handle the increased flow of wastewater.
The upgrading of a pumping unit could include higher-horsepower equipment, but it is not possible to do this without considering the entire system. To get more powerful pumps there is a possibility that you will need to make changes to the discharge elbows or piping. It is also possible to alter electrical controls and valves.
Engineers must also consider the hydraulic requirements of the system, which includes the rate of flow and the dynamic head total. If you add a larger pump without evaluating these conditions the system could cause operational problems rather than resolve them. Planning for future capacity during the initial design can allow for later expansion much more easily.
Make sure that the waste water is moving during construction
A wastewater pump station retrofit introduces a challenge that ordinary replacement of equipment projects do not face: the station might require to be operational throughout the construction.
When contractors aren’t busy they continue to receive wastewater. According to the study it is possible that a temporary bypass pumping system might be needed to keep service running while the existing equipment is taken down or new components are added.
Romtec Utilities accepted this challenging task at the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project consisted of replacing two older wastewater lift stations as well as maintaining the operation of the facility. The project was able accommodate the footprints of existing stations as well as operational requirements by using customized engineering on site and system for replacement that is packaged. This case illustrates why it is important to look at the construction process prior to installing.
In the event that replacement is not an option, it’s the best option, replace it.
Not every station is suited for rehabilitation. Sewer lift stations might have to be rebuilt for a damaged wet well or a lack of capacity for structural strength.
It is essential that the choice taken into account structural factors as well as equipment compatibility and accessibility to construction as well being long-term operational needs. Romtec Utilities begins retrofit and replacement projects by determining what components will be left and which will require replacement.
The company develops site-specific engineering solutions, preliminary designs, and budgetary estimates. Prefabricated components can also help to organize installation and decrease some building requirements that are required on-site.
The project won’t be finished until the pumps kick in
Modern lift stations should operate as a system. Before returning a lift station to normal service, restart tests, commissioning as well as verification of the equipment are essential to confirm that all pumps, control systems, and the related equipment function as designed.
Manuals for operation and maintenance along with training for operators, are important. Prior to taking over the responsibility of a station, maintenance personnel must be aware of new equipment, procedures and documents.
A successful retrofit preserves infrastructure that still has value while addressing the issues that forced modernization.
For municipal facilities and facility owners This means looking beyond immediate repairs. The strongest project is one that integrates new equipment into existing structures, provides essential service throughout construction, and prepares the pumping system to last for years of continuous operation.