The municipality has an old wastewater lift station. Pumps are nearing the end of their useful life, while controls need to be modernized and the access hatch has to be replaced. While the concrete wetwell is structurally sound, it’s time to be upgraded.
Do you think the station should be completely destroyed? Not necessarily. The better question is whether the current infrastructure can support a modern pumping system without compromising security, maintenance access or capacity in the future.
Image credit: romtecutilities.com
A well-designed pump station retrofit can preserve important infrastructure and replace components that are no longer in compliance with operating requirements.
Begin with the Structures that nobody Wants To Replace
It is expensive and disruptive to change the wet well because it is buried beneath the earth, and is connected to pipes and essential for the collection of wastewater.
The concrete structure can be retained to make it easier to dig and build.
However, deterioration near the hatch could complicate your decision. Romtec Utilities says that wet well hatches are often replaced as part of retrofits. Instead of attaching the hatch to cement that has deteriorated replacing the whole top layer might be a more reliable option. This can increase access to the structure, and extend its utility, without having to replace the entire structure as well.
The technology behind pumps that are more powerful is different
Think about a community that has experienced a significant increase in population since the construction of its lift station. The existing pumps may not be able to handle the demand for increased wastewater flows.
The upgrade of a pumping unit could include higher-horsepower equipment, but this isn’t possible without considering the surrounding system. Pumps with greater power may require changes to elbows for discharge, piping valves, electrical controllers, and other components.
Engineers must also evaluate the system’s hydraulic requirements, including the flow rate and the total dynamic head. In the event of installing a larger pump, not reviewing these conditions can create problems with operation rather than addressing them. Making plans for future capacity in the initial design can help later expansions to be much easier.
Make sure that the wastewater is moving during construction.
Retrofitting a wastewater pump station can be the challenge of a completely new one. As with other equipment replacement projects, this one will need to continue operating for the duration of construction.
Contractors continue to work and wastewater continues to come in. According to the project an interim bypass pumping system may be necessary to maintain service as existing equipment is removed or new components installed.
Romtec Utilities was able to take on this task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project consisted of replacing two older wastewater lift stations as well as maintaining the operation at the facility. Specific engineering for the site packages, replacement systems for packaged equipment, and bypass pumping techniques helped allow for the station’s footprints as well as operational requirements. This illustrates how important it is to think about the sequence of construction prior to constructing.
If you decide to replace, it is the best Option
Some stations are not suitable to be renovated. A severely deteriorated wet well, inadequate structural capacity, or major changes in hydraulic requirements may make sewer lift station replacement more appropriate than modifying the existing installation.
The decision should account for structural condition, equipment compatibility, construction access as well as service continuity as well as long-term requirements for operation. Romtec Utilities begins retrofit and replacement projects by determining what elements will remain and which will require replacement.
The business will then design sites-specific engineering designs along with budget estimates and preliminaries of designs. Prefabricated components are also beneficial for organizing installation and reducing certain requirements on site.
The project isn’t finished when the pumps are turned on
The modern lift station needs to work as a whole. Prior to returning it back to normal service, it is necessary to start testing and commissioning help verify that the controls, pumps, and other equipment are operating according to the established design.
Both manuals and training for operators are equally important. Maintenance personnel should be knowledgeable with the latest equipment and operating procedures as well as the documents before taking charge of the station.
A successful retrofit helps preserve infrastructure that still has value while addressing the limitations that led to modernization being necessary.
This means that municipalities and owners of facilities must take a look beyond the immediate fixes. Most successful projects blend new equipment with existing structures. They will maintain the vital services throughout construction and then prepare the pumping systems to last for a long time.