A municipality has an outdated wastewater lift station. The pumps have reached the maximum lifespan and the controls are dated, as well as the access hatch is degraded. Yet the concrete wet well is structurally sound.
Should the station be completely removed? Not necessarily. The more important issue is whether the current infrastructure is able to support a modern pumping system with no compromise in availability, reliability or capacity in the future.
Image credit: romtecutilities.com
Retrofitting an existing pump station can be an excellent way to maintain infrastructure and replace components that are no longer functional.
Begin with the Structure that nobody is Trying to Replace.
Wet wells are usually the most expensive and difficult component to replace, as they are submerged and linked to pipes that are already in place, and essential to the collection of wastewater.
The retention of a concrete structure that is functional can reduce the excavation and construction.
However, the deterioration of the access hatch may complicate the choice. Romtec Utilities identifies wet well hatch replacement as a common retrofit requirement. Instead of gluing a hatch to cement that is deteriorating replacing the whole top layer might be more durable. This option can be utilized to increase access and improve the structural’s functionality without the need to replace the entire wet well.
The design of a more powerful pump is different
Imagine a place that has increased significantly since the lift station’s initial installation. It is possible that the current pumps aren’t capable of handling the increased water flow.
A pumping station upgrade could involve higher-horsepower pumps, but equipment selection cannot happen independently of the surrounding system.
Engineers should also consider the hydraulic requirements of the system. This is a consideration for flow as well as the total dynamic pressure. In the event of installing a larger pump, not taking a look at these requirements could cause problems with operation rather than addressing the issues. Planning future capacity prior to designing the initial design makes expansion later significantly easier.
Make sure that the wastewater is kept moving during Construction
A retrofit to a wastewater pump station introduces a challenge that ordinary replacement of equipment projects do not be able to overcome: the station may require operation throughout construction.
Contractors continue working and wastewater continues to come in. In the case of a project an interim bypass pumping system may be necessary to ensure the service until existing equipment is taken away and new components are put in place.
Romtec Utilities embraced this difficult task in the Federal Law Enforcement Training Center, Brunswick, Georgia.
The project included replacing two older wastewater lift stations and ensuring the operations of the facility. Site-specific engineering as well as packaged systems and bypass pumping techniques made it possible to meet existing station footprints as well as operational requirements. This is a good example of why the sequence of construction is important to consider prior to installation.
In the event that replacement is not an option, it’s the best option, replace it.
Some stations may not be suited for rehabilitation. If the sewer lift station requires replacement due to a badly deteriorated well, structural problems or significant changes in the hydraulic requirements, it could be more beneficial to replace rather than modify.
It is essential that the decision taken takes into account structural conditions the compatibility of equipment and accessibility to construction, as in the long-term requirements for operation. Romtec Utilities starts retrofitting and replacing projects by identifying components that will be retained and those that will need to be replaced.
The company then develops engineering solutions tailored to the location, including preliminary designs and budget estimates. Prefabricated parts are also helpful for organizing installation and reducing certain on-site demands.
The project won’t be finished until the pumps kick in
Modern lift stations need to be operated as an integrated system. Before returning it to normal service, it is necessary to start testing and commissioning will help ensure that the controls, pumps and other equipment are operating according to the approved design.
Both manuals and training for operators are equally essential. Maintenance personnel should be knowledgeable with the new equipment and operating procedures, and the documentation before they take responsibility for the station.
A successful retrofit preserves the infrastructure that is still valuable while addressing the issues that forced modernization.
This means that municipalities as well as facility owners must consider more than just immediate repairs. The most successful projects combine new equipment and existing structures. They provide essential services while construction is underway and set up the pumping system for a lifetime of operation.